Made available in DSpace on 2014-06-11T19:27:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-06-29Bitstream added on 2014-06-13T19:15:37Z : No. of bitstreams: 1 martins_lg_me_sjc.pdf: 695176 bytes, checksum: fb089e33ad4b62aa9c5866bfb90390b7 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A ação de beta-bloqueadores na melhoria da qualidade óssea e sua ação anti-inflamatória embasam a hipótese de que a modulação simpática pode influenciar a evolução da doença periodontal (DP). Estudos demonstram relação entre disfunção salivar e DP; no entanto, os efeitos da DP nas glândulas salivares, cuja secreção é controlada pelo sistema nervoso autônomo, são pouco estudados. Objetivou-se analisar os efeitos do bloqueio e da ativação de receptores beta-adrenérgicos na reabsorção alveolar na DP em ratos, assim como os efeitos da DP, associada ou não a tratamento adrenérgico, nas glândulas salivares. Foram utilizados 40 ratos divididos em quatro grupos: (1) Grupo Propranolol 0,1mg/Kg com indução de DP; (2) Grupo Isoproterenol 0,75mg/Kg e DP; (3) Grupo Controle sem DP, com administração solução fisiológica ; (4) Grupo Controle com DP, com administração solução fisiológica. Depois de 14 dias de tratamento, ocorreu a eutanásia. Removeram-se as hemimandíbulas e as glândulas submandibulares e sublinguais para análise. O suporte e a perda óssea alveolar foram determinados radiográfica e macroscopicamente. As glândulas foram pesadas, medidas e submetidas à preparação de rotina para coloração com hematoxilina e eosina e Alcian Blue. Avaliou-se histomorfometricamente a área de ácinos, ductos e a vacuolização celular. Após estatística (p<0,05), verificou-se menor suporte e maior perda alveolar na presença de ligadura e maior perda alveolar em animais com tratados com isoproterenol. O isoproterenol aumentou significantemente peso e dimensões glandulares, reduziu área ductal e vacuolização, e aumentou área acinar na submandibular. Propranolol apenas reduziu vacuolização em relação ao controle com DP, e as demais comparações não foram estatisticamente significantes... / The action of beta-blockers in the improvement of bone quality and their anti-inflammatory actions base the hypothesis that sympathetic nervous system modulation can influence periodontal disease (PD). Studies demonstrate a relationship between salivary dysfunction and PD; however, there are few studies about the effects of PD in salivary glands, whose secretion is controlled by the autonomic nervous system. The aim of this study was to analyze the effects of the blockade and of the activation of beta-adrenergic receptors in alveolar resorption in PD in rats, as well as the effects of PD, associated or not to adrenergic treatment, in salivary glands. Forty rats were divided into four groups: (1) group Propranolol 0.1mg/Kg with PD induction; (2) group Isoproterenol 0.75mg/Kg and PD; (3) group Control without PD, which received saline; (4) group Control with PD, which also received saline. After 14 days of treatment, euthanasia occurred. Hemimandibles and submandibular and sublingual glands were removed for analysis. Alveolar bone support and alveolar bone loss were evaluated by radiographic and macroscopic analysis. Gland weight and dimensions were measured, and then the samples were submitted to routine preparation for hematoxilin and eosin and Alcian blue stainings. Acinar and ductal area and cellular vacuolization were histomorphometrically evaluated. After statistical analysis (p <0.05), less alveolar bone support and larger alveolar loss were verified in animals with ligatures for PD induction and larger alveolar loss were also verified in rats treated with isoproterenol. Isoproterenol also increased significantly glandular weight, size and acinar area, and reduced ductal area and cellular vacuolization in submandibular glands. Group Propranolol presented less vacuolization than group Control with DP... (Complete abstract click electronic access below)

An exceptionally important stress response of Pseudomonas putida strains to toxic chemicals is the induction of efflux pumps that extrude solvents, as well as other toxicants, into the surrounding medium. However, the bacterial tolerance mechanisms are still not fully understood, thus in this thesis metabolomic approaches were used to detect and identify metabolites involved in P. putida DOT-T1E tolerance to abiotic stresses, in particular focussing on the role of efflux pumps. To elucidate any metabolome alterations several strains of P. putida, including the wild type DOT-T1E, and the efflux pump knockouts DOT-T1E-PS28 and DOT-T1E-18, were challenged with different levels of propranolol. Fourier-transform infrared (FT-IR) spectroscopy, which provided a rapid, high-throughput metabolic fingerprint of P. putida strains, was used to investigate any phenotypic changes resulting from exposure to propranolol. FT-IR data illustrated phenotypic changes associated with the presence of propranolol within the cell that could be assigned to the bacterial protein components. To complement this phenotypic fingerprinting approach metabolic profiling on the same samples was performed using gas chromatography mass spectrometry (GC-MS) to identify metabolites of interest during growth of bacteria following this toxic perturbation with propranolol. GC-MS revealed significant changes in ornithine levels which can be directly linked to bacterial tolerance mechanisms, and alterations in the levels of several other metabolites which were also modified in response to propranolol exposure. Moreover, the effect of the organic solvent toluene was also investigated using the same approach. Examination of FT-IR data indicated that protein and fatty acids were the most affected components of P. putida strains due to the presence of toluene within the cell. Moreover, application of GC-MS allowed for the identification and quantification of several metabolites which were differentially produced or consumed in the presence of toluene. To investigate the role of efflux pumps in P. putida DOT-T1E, several analytical techniques were employed including Raman spectroscopy, gas and liquid chromatography to identify and quantify the level of propranolol or toluene in P. putida cells. These analyses showed that propranolol and toluene accumulated in the mutant P. putida DOT-T1E-18 (lacking the TtgABC pump) at higher levels in comparison with the levels found in the wild-type DOT-T1E and the mutant DOT-T1E-PS28 (lacking the TtgGHI pump), indicating the key role of efflux pumps in solvent tolerance. Furthermore, the effect of Mg2+ and Ca2+ on the stabilisation of the toluene tolerance of P. putida DOT-T1E strains was examined in order to elucidate whether divalent cations interact with efflux pumps or other resistant mechanisms to improve solvent tolerance. FT-IR analysis suggested that the influence of divalent cations on the stabilisation of the toluene tolerance could be due to the contribution of metal ions towards other tolerance mechanisms such as lipopolysaccharide (LPS) instead of enhancing the activity of efflux pumps. In conclusion, this thesis presents evidence that phenotypic fingerprinting and metabolic profiling approaches in combination with chemometric methods can generate valuable information on phenotypic responses occurring within microbial cultures subjected to abiotic stress.

Succinate is a dicarboxylic acid that accumulates due to succinate dehydrogenase inhibition. This dicarboxylic acid has a biphasic effect on neural activity in vitro that seems to be mediated by N-methyl-D-aspartate (NMDA) receptors. The NMDA receptor is distributed throughout the central nervous system and mediates synaptic plasticity-related events, such as learning and memory. Although it has been described that succinate modulates NMDA conductance, it is not known if this organic acid modulates learning and me mory. Therefore, in the present study we investigated whether the immediate post-training systemic or intrahippocampal administration of succinate affects the memory of fear conditioning in rats. In addition, we investigated whether the NMDA and β-adrenergic receptors are involved in the facilitatory effect of succinate on memory. Systemic (0,00005, 0,0005, 0,005, 0,05 and 0,5 mg/kg i.p) or bilateral intra-hippocampal (0.21 pmol i.h.) immediate post-training administration of succinate biphasically facilitated contextual fear conditioning and had no effect on conditioning to tone. Systemic or intra-hippocampal administrations of MK-801 (0,001 mg/kg i.p. or 0,21 pmol i.h. respectively), a noncompetitive NMDA receptor antagonist, at a dose that had no effect per se, reversed the facilitatory effect of succinate on contextual fear conditioning. The systemic administration of propranolol (10 mg/kg i.p.), a β-adrenergic antagonist, at a dose that had no effect per se, also reversed the facilitatory effect of succinate on contextual fear conditioning. The administration of succinate (0,005 mg/kg i.p.) immediately after training and 15 minutes before the test did not affect the performance of the animals on fear conditioning. These results suggest that the facilitatory effect of succinate on the memory of fear conditioning involves NMDA and β-adrenergic receptors. The results also indicate that the facilitatory effect of succinate on memory is not related to state-dependence / O sucinato é um intermediário do ciclo de Kreks e também da cadeia respiratória, mas que também parece ter funções não relacionadas ao metabolismo energético. De fato, este ácido dicarboxílico tem efeito bifásico sobre a atividade neural in vitro, que parece ser mediado pelo receptor glutamatérgico N-metil-D-aspartato (NMDA). O receptor NMDA está presente em todo o sistema nervo central (SNC) e os processos mediados por este receptor incluem plasticidade sináptica e formação de circuitos neurais. Embora tenha sido descrito que o sucinato modula a atividade neural in vitro, não se sabe se este ácido orgânico modula processos fisiológicos ligados ao receptor NMDA, como o aprendizado e memória. Consequentemente, neste estudo foi investigado o efeito da administração sistêmica e intrahipocampal de sucinato, MK-801 e propranolol sobre a consolidação da memória em ratos, utilizando a tarefa de medo condicionado clássico. Posteriormente se investigou se os efeitos do sucinato sobre a memória envolvem dependência de estado. O teste do medo condicionado consistiu na apresentação de estímulos pareados, condicionado (tom 2000 Hz 90 dB/10 s) e incondicionado (choque 0.6 mA/1 s). O estado de imobilidade do animal foi utilizado como um indicativo de memória nas sessões de avaliação de memória ao contexto e ao tom. A administração sistêmica de sucinato nas doses de 0,00005, 0,0005, 0,005, 0,05 e 0,5 mg/kg i.p. imediatamente após o treino melhorou a memória. Contudo, a dose de 5 mg/kg de sucinato não alterou a memória dos animais, caracterizando um efeito bifásico sobre a memória. Essa melhora da memória induzida por sucinato (0,005 mg/kg i.p.) foi revertido pela administração pós-treino de um antagonista do receptor NMDA, MK-801 (0,001 mg/kg i.p.) e pela administração imediatamente após o treino de um bloqueador adrenérgico, propranolol (10 mg/kg i.p.). A administração de sucinato (0,005 mg/kg i.p.) imediatamente após o treino e 15 minutos antes do teste não afetou a performance dos animais, não caracterizando dependência de estado. Nos experimentos que visaram identificar se a administração central de sucinato alterava a memória, os animais foram canulados bilateralmente no hipocampo e após a recuperação cirúrgica, recebiam injeções bilaterais imediatamente após o treino, de sucinato (0,21 pmol i.h.) que melhorou a memória. A administração imediatamente após o treino de MK- 801 (0,22 nmol i.h.) foi capaz de reverter esse efeito facilitador do sucinato sobre a memória. Estes resultados sugerem que o efeito facilitador da memória induzida pela administração de sucinato é mediado pelo receptor NMDA e envolve de alguma maneira o sistema adrenérgico

Die therapeutische Beeinflußbarkeit einer Leberverfettung gilt weltweit als unbefriedigend ge-löst, so daß ein letaler Ausgang besonders bei Wiederkäuern teilweise nicht zu verhindern ist. Die Nutzung von beta-Rezeptorenblockern hat bisher mit dieser Indikation keinen Eingang in die Veterinärmedizin gefunden. In den vorliegenden Untersuchungen wurden deshalb die Auswirkungen einer unspezifischen Blockade der beta-adrenergen Rezeptoren auf die Lipolyse, die klinischen und hämatologi-schen Funktionen sowie Leber-, Eiweiß- und Mineralstoffwechsel bei fastenden Schafen ge-prüft. Insbesondere wurde dabei die Wirkung einer Propranololapplikation auf die Lipolyse in der frühen Phase des Fastens untersucht. Zu diesem Zweck wurden insgesamt 15 weiblichen, klinisch gesunden, güsten Schafen der Rasse Merino-Fleisch während eines dreitägigen Futterentzuges mit Hilfe einer Dauertropfinfu-sion mit zwei 8stündigen Pausen 0,5 bzw. 1 mg Propranolol/kg KM/d bzw. den Tieren der Kontrollgruppe ein vergleichbares Volumen einer NaCl-Lösung appliziert. Neben der klini-schen Kontrolle von Puls- und Atemfrequenz, Körpertemperatur und Pansenaktivität erfolgte über die wiederholte Gewinnung von Blutproben aus der Vena jugularis externa eine Erfassung der Konzentrationen von Glucose, FFS, Bilirubin, BHB, K, Na, Mg, Gesamteiweiß und Albu-min im Blutserum. Zur Kontrolle der Leberfunktion wurden die Aktivitäten der GLDH und ASAT bestimmt. Die Wirkung des beta-Rezeptor-Antagonisten Propranolol auf die hämatolo-gischen Parameter wurde durch die Kontrolle der Leukozyten-, Erythrozyten- und Hämoglo-binkonzentrationen und den Hämatokrit der Schafe im Versuchsverlauf überprüft. In Übereinstimmung mit bisherigen Untersuchungen an Wiederkäuern und Nichtwiederkäuern kam es aufgrund der dreitägigen Futterdeprivation in allen Tiergruppen zu einer signifikanten Verminderung des Körpergewichtes um bis zu 9,8 %. Die Zahl der Pansenbewegungen redu-zierte sich bei allen Tieren signifikant bereits innerhalb der ersten 48 Stunden der Futterdepri-vation. Der stärkste Abfall der Pansenaktivität ließ sich bei den Schafen, denen 1 mg Propra-nolol/kg KM/d infundiert wurde, nachweisen. Puls- und Atemfrequenz, die Konzentrationen von Na, K, Mg, Gesamteiweiß und Albumin sowie die Aktivitäten von GLDH und ASAT im Blutserum blieben im Versuchsverlauf ohne signifikante Veränderungen. Eine Beeinflussung der hämatologischen Parameter ließ sich we-der bei den Schafen der Kontrollgruppe noch bei denen der Versuchsgruppen nachweisen. Während der Futterentzug in allen Tiergruppen zu einer tendenziellen Abnahme der Blut-serumkonzentration an Glucose führte, stiegen die Konzentrationen an FFS, Bilirubin und BHB im Blutserum aller Tiere an. Damit weisen die Veränderungen in den Konzentrationen von FFS, BHB und Bilirubin im Blutserum der Schafe der Kontrollgruppe die typischen Merkmale einer Fastenstoffwechsellage auf. In beiden Versuchsgruppen fielen diese Konzen-trationserhöhungen gegenüber denen der Kontrollgruppe statistisch gesichert niedriger aus. Unter Berücksichtigung der dabei erreichten Niveaus ließ sich für die Versuchsgruppen eine geringere Belastung von Energie- und Leberstoffwechsel als in der Kontrollgruppe feststellen. Der Übergang von der ersten in die zweite Phase des Fastenstoffwechsels ist in allen Tiergrup-pen, besonders deutlich in beiden Versuchsgruppen, zum Zeitpunkt um 48 h nach Versuchsbe-ginn an der Erhöhung der Körpertemperatur sowie den stärkeren Anstiegen der FFS-Konzentrationen erkennbar. Die besondere klinische und labordiagnostische Bedeutung der Änderungen der FFS-Konzentration im Blutserum zeigte sich in der zeitlich früheren und ausgeprägteren Reaktion als die Konzentrationsänderungen von Bilirubin und BHB. Bereits nach 24stündigem Fasten waren in allen Schafgruppen signifikant gegenüber den Ausgangswerten erhöhte FFS-Konzentrationen nachweisbar. In beiden Versuchsgruppen war bis zum Erreichen der Maxi-malwerte 48 h nach Beginn des Fastens ein geringerer Anstieg der FFS-Konzentration im Blut-serum als in der Kontrollgruppe nachzuweisen. Nach dem Erreichen der Maximalkonzentration kam es unter dem Propranololeinfluß in beiden Versuchsgruppen zu einem raschen, signifi-kantem Abfall der FFS-Konzentration um 44,7 bzw. 63,5 %. Die Abnahme der FFS-Konzentration im Blutserum vom Maximalwert bis zum Versuchsende betrug in der Kontroll-gruppe lediglich 8,6 %. und lag damit signifikant unter den Vergleichswerten der Versuchstie-re. Für die Konzentration der FFS fanden sich zum Versuchsende zwischen allen Gruppen si-gnifikante Unterschiede. Damit läßt sich eine dosisabhängige Wirkung einer Propranololappli-kation auf die Freisetzung von FFS aus den körpereigenen Fettdepots ableiten. Als Besonderheit war zu beobachten, daß sich die Konzentration der FFS in der Kontrollgrup-pe in den Zeiträumen der Infusion der NaCl-Lösung vermindert. Möglicherweise spielt hierbei der säuernde Einfluß des NaCl auf den pH-Wert im Blut eine Rolle. Unter dem Einfluß einer pH-Verminderung kommt es dabei zu einer Absenkung der Lipolyserate. Der zwischen den Infusionszeiten starke Konzentrationsanstieg der FFS in der Kontrollgruppe führt in dieser zu signifikant höheren FFS-Konzentrationen als in den Versuchsgruppen. Die Konzentrationsänderungen von direkt reagierendem und Gesamtbilirubin fielen bei den Schafen der Kontrollgruppe höher aus als bei den Tieren der Versuchsgruppen. Während die Maximalkonzentrationen für das Gesamtbilirubin in den Versuchsgruppen mit Dosierungen von 0,5 bzw. 1 mg Propranolol/kg KM/d 48 h nach Versuchsbeginn erreicht werden, ließen sich die maximalen Gesamtbilirubinkonzentrationen in der Kontrollgruppe erst 56 h nach Versuchsbe-ginn nachweisen. Die dabei vorhandenen Konzentrationsunterschiede zwischen den einzelnen Gruppen weisen auf eine geringere Belastung der Leber bei den Schafen der Versuchsgruppen hin. Auch die BHB-Konzentrationen im Blutserum der Schafe der Versuchsgruppen lagen zum Versuchsende unter denen der Tiere in der Kontrollgruppe. Damit liegt ein weiterer Indikator auf eine geringere Leberbelastung der Tiere in den Versuchsgruppen gegenüber den Schafen der Kontrollgruppe vor. Die absolut niedrigsten BHB-Konzentrationen waren bei den Schafen der Versuchsgruppe mit einer Propranololgabe von 1 mg/kg KM/d nachweisbar. In dieser Gruppe wurde die maximale BHB-Konzentration 32 h nach Fastenbeginn erreicht. Die vorliegenden Ergebnisse zeigen, daß sich mit Propranololgaben in Höhe von 0,5 bzw. 1 mg/kg KM/d beim Schaf eine Hemmung der Lipolyse innerhalb der ersten 64 Stunden eines Futterentzuges erreichen läßt, ohne dabei nachweisbaren Einfluß auf hämatologische Parameter auszuüben. Insbesondere weisen die zwischen Versuchs- und Kontrollgruppe vergleichbaren Anstiege der FFS-Konzentrationen in den infusionsfreien Zeiträumen auf den Einfluß des beta-adrenergen Antagonisten auf die Lipolyse während der Infusion hin. Die Konzentrationsände-rungen von Bilirubin und BHB in den Versuchsgruppen erfolgen in deutlich geringerem Um-fang als in der Kontrollgruppe. Damit läst sich auf eine geringere Belastung von Energie- und Leberstoffwechsel bei den Versuchstieren schließen. Die nicht signifikanten Veränderungen der Enzymaktivitäten von GLDH und ASAT bestätigen, daß durch die Anwendung von Propra-nolol keine negative Beeinflussung der Leberfunktion erfolgt. Aufgrund der stärkeren Reduzie-rung der Zahl der Pansenbewegungen und des verminderten Konzentrationsanstieges von FFS im Blutserum der Schafe, denen 1 mg Propranolol/kg KM/d appliziert wurde, gegenüber denen die 0,5 mg Propranolol/kg KM/d erhielten, ist von einer Dosisabhängigkeit der Propranolol-wirkung auszugehen. Die Applikation von Propranolol in einer Dosis von 0,5 bzw. 1 mg/kg KM/d stellt beim Schaf eine geeignete Methode dar, frühzeitig eine Verminderung der fasten-induzierten Lipolyse zu erreichen. / The treatment of the fatty liver disease is world-wide regarded as unsatisfactory, so that death of the affected ruminants is partly unavoidable. The administration of beta receptor blockers in such cases has not found its way into veterinary medicine until now. In this study, the effects of a nonspecific blockade of the beta adrenoceptors on lipolysis, clinical and hematological parameters as well as on the metabolism of the liver, proteins and minerals in fasting sheep were therefore tested. Especially, the effect of a Propranolol administration on the lipolysis in the early stage of fasting was examined. During a three-day period of food deprivation, 15 female, clinically healthy and non-pregnant sheep (Merino-Fleisch) were given 0.5 or 1 mg Propranolol/kg body weight per day via a continuous infusion with two interruptions of eight hours. During the experiment, pulse, respiration rate, body temperature and rumen activity were checked. The serum concentrations of glucose, FFA, bilirubin, beta-hydroxybutyrate, potassium, sodium, magnesium, total protein and albumin were controlled by repeatedly taking blood samples from the vena jugularis externa. The activity of the enzymes GLDH and AST were determined to check the liver function. The effect of the beta-receptor antagonist Propranolol on the hematological parameters was checked by examining the WBC, RBC, the hemoglobin concentrations and the packed cell volume. All test groups showed significant decrease in body weigth of up to 9.8 %, due to the three-day food deprivation. Even within the first 48 hours of food deprivation, rumen motility of all animals was decreasing significantly. Those sheep which received 1 mg Propranolol/kg body weight per day showed the strongest decrease in rumen activity. Pulse and respiration rate, the concentrations of potassium, sodium, magnesium, total protein and albumin as well as the activity of GLDH and AST in blood serum remained without significant changes during the experiment. Neither the sheep of the control group nor those of the experimental groups showed any influence on the hematological parameters. While the blood glucose concentration tended to be lower during the food deprivation in all groups, the concentrations of FFA, bilirubin and beta-hydroxybutyrate in blood serum were increasing. Thus, the changes of FFA, bilirubin and beta-hydroxybutyrate concentrations in the control group showed the typical characteristics of fasting metabolism. These absolute increases in concentrations were significantly lower in both experimental groups than those in the control group. With regard to the levels reached and compared to the control group, a smaller load of energy and liver metabolism could be determined in the experimental groups. The transition from the first to the second stage of the fasting metabolism in all groups (but especially in the experimental groups) was clearly discernible in the rises of body temperature and in the stronger increases of the FFA concentrations approximately 48 hours after the experiment started. The special clinical and diagnostic importance of the FFA concentration was indicated in an earlier and stronger change of the FFA concentration in the blood serum, compared to the changes of bilirubin and beta-hydroxybutyrate. As early as 24 hours after the beginning of the fasting, a significant rise of the FFA concentration in comparison to the initial concentration could be proved. In contrast to the control group the two experimental groups showed a smaller increase in the FFA concentration. All groups reached their maxima of FFA concentration 48 hours after the beginning of the experiment. Afterwards FFA concentrations in the two experimental groups were sinking fast and significantly by 44.7 % and 63.5 % respectively. In the control group, the decrease of the FFA concentration from the maximum until the end of the experiment was only 8.6 % and thus significantly lower than the comparative results. At the end of the experiment, significant differences in FFA concentrations between all groups could be proved. So, it can be assumed that there is a dose-dependent effect of Propranolol on the FFA release from the bodyŽs own fat depots. The FFA concentration in the control group was decreasing during the NaCl-infusion. This could be due to NaClŽs influence on the pH value of the blood. The reduction of the pH causes a decreasing rate of the lipolysis. The strong rise of FFA concentration between the infusion in the control group, lead to significantly higher results compared to the experimental groups. The changes of total and direct reacting bilirubin in the control group were higher than in the experimental groups. While maximum concentrations of total bilirubin acid in the experimental groups (which got 0.5 and 1 mg Propranolol/kg body weigth per day respectively) could be determined 48 hours after the experimentŽs start, maximum concentrations in the control group could be found only 56 hours after beginning of the fasting. Beta-hydroxybutyrate concentrations in the experimental groups were also lower than in the control group. These differences between the groups indicate a smaller strain of the liver in the experimental groups. The lowest beta-hydroxybutyrate concentrations could be proved in the experimental group with a dose of 1 mg Propranolol/kg body weight per day. In this group, the maximum beta-hydroxybutyrate concentration was reached 32 hours after the beginning of the fasting. These results suggest that by the administration of Propranolol at doses of 0.5 mg and 1 mg/kg body weigth per day respectively it is possible to inhibit the lipolysis within the first 64 hours after a food deprivation without effecting the hematological parameters. Particularly, the comparable increases in FFA concentrations in the experimental and control groups between the infusions indicate a direct effect of the beta-adrenergic antagonist on the lipolysis during the infusions. The changes of bilirubin and beta-hydroxybutyrate concentrations in the experimental groups were smaller than those in the control group. This suggests a smaller strain on the energy and liver metabolism in the experimental groups compared to the control group. The nonsignificant changes of the activity of GLDH and AST indicate no negative influence on the liver function after applicating Propranolol. The stronger reduction of rumen motility and the smaller increase of the FFA concentration in the group with 1 mg Propranolol/kg body weigth per day compared to the group with 0.5 mg Propranolol/kg body weigth per day shows the dose-dependent effect of Propranolol. The application of Propranolol at a dose of 0.5 mg or 1 mg/kg body weigth per day is a suitable method to early inhibit fasting-induced lipolysis in sheep.

No / The electrophoretic mobilities of three beta-blocker drug practolol, timolol and propranolol, have been measured in electrolyte systems with mixed binary and ternary water-methanol-ethanol solvents with acetic acid/sodium acetate as buffer using capillary electrophoresis. The highest mobilities for the analytes studied have been observed in pure aqueous. the lowest values in ethanolic buffers The measured electrophoretic mobilities have been used to evaluate the accuracy of a mathematical model based on a mixture response surface method that expresses the mobility as a function of the solvent composition. Mean percentage error (MPE) has been computed considering experimental and calculated mobilities as an accuracy criterion. The obtained MPE for practolol, timolol and propranolol in the binary mixtures are between 0.9 and 2.6%, in the ternary water-methanol-ethanol solvent system the MPE was about 2.7%. The MPE values resulting from the proposed equation lie within the experimental relative standard deviation values and can he considered as an acceptable error.

Synapses can be altered due to experiences in a process called synaptic plasticity, which causes memory formations. Synapses can be strengthened through methods known as long-term potentiation (LTP) or weakened through long-term depression (LTD). Stresses can cause changes by altering synapses through either LTP or LTD. Rats were used to study the effects of post-traumatic stress disorder (PTSD)-like symptoms and a prophylactic treatment using pharmaceuticals. The first model used was the single prolonged stress (SPS) with two weeks of chronic light, which was not as effective for causing changes in synaptic plasticity. The second model, seven days of social defeat (SD) with two weeks of chronic light was more effective at inducing PTSD-like behavior symptoms and causing changes in LTP levels in the ventral hippocampus, amygdala, and prefrontal cortex between stressed and non-stressed rats. For the prophylactic treatment, propranolol and mifepristone were administered one week prior to and throughout the two weeks of the social defeat protocol. The drugs were able to prevent the changes due to stress on LTP in the three aforementioned brain regions, but did not change the anxious behavior of the rats. An enzyme-linked immunosorbent assay (ELISA) was used to determine corticosterone and norepinephrine levels between the different groups of rats. No significant differences were detected between SD and control rats, but SD injected rats were different from controls indicating that the injections were causing added stress. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) was used to detect changes in the adrenergic, corticoid, AMPA, and NMDA receptors. There were a few significant changes to some of the targets indicating that the stress protocol and drugs were having an effect on the mRNA expression. Propranolol and mifepristone could possibly be used as a prophylactic treatment for traumatic stress. In a separate study, techniques were used to determine the negative effects chronic stress (non-PTSD-like) has on synaptic plasticity in the dorsal hippocampus and to show how exercise was able to mitigate some of those negative stress effects. Electrophysiology showed differences in LTP between four groups of mice: sedentary no stress (SNS), sedentary with stress (SWS), exercise with stress (EWS), and exercise no stress (ENS). SWS had the lowest amount of LTP, whereas ENS had the highest. SNS and EWS had similar levels of LTP, which were in between the SWS and ENS groups. Corticosterone blood levels measured by an ELISA showed significant increases in the stressed groups compared to the non-stressed groups. The radial arm maze showed that both groups of exercise mice made fewer reference memory errors the second week of testing compared to the sedentary groups. RT-qPCR determined that brain-derived neurotrophic factor (BDNF) and corticoid and dopamine 5 receptors were likely causing some of the memory changes.

Synapses can be altered due to experiences in a process called synaptic plasticity, which causes memory formations. Synapses can be strengthened through methods known as long-term potentiation (LTP) or weakened through long-term depression (LTD). Stresses can cause changes by altering synapses through either LTP or LTD. Rats were used to study the effects of post-traumatic stress disorder (PTSD)-like symptoms and a prophylactic treatment using pharmaceuticals. The first model used was the single prolonged stress (SPS) with two weeks of chronic light, which was not as effective for causing changes in synaptic plasticity. The second model, seven days of social defeat (SD) with two weeks of chronic light was more effective at inducing PTSD-like behavior symptoms and causing changes in LTP levels in the ventral hippocampus, amygdala, and prefrontal cortex between stressed and non-stressed rats. For the prophylactic treatment, propranolol and mifepristone were administered one week prior to and throughout the two weeks of the social defeat protocol. The drugs were able to prevent the changes due to stress on LTP in the three aforementioned brain regions, but did not change the anxious behavior of the rats. An enzyme-linked immunosorbent assay (ELISA) was used to determine corticosterone and norepinephrine levels between the different groups of rats. No significant differences were detected between SD and control rats, but SD injected rats were different from controls indicating that the injections were causing added stress. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) was used to detect changes in the adrenergic, corticoid, AMPA, and NMDA receptors. There were a few significant changes to some of the targets indicating that the stress protocol and drugs were having an effect on the mRNA expression. Propranolol and mifepristone could possibly be used as a prophylactic treatment for traumatic stress. In a separate study, techniques were used to determine the negative effects chronic stress (non-PTSD-like) has on synaptic plasticity in the dorsal hippocampus and to show how exercise was able to mitigate some of those negative stress effects. Electrophysiology showed differences in LTP between four groups of mice: sedentary no stress (SNS), sedentary with stress (SWS), exercise with stress (EWS), and exercise no stress (ENS). SWS had the lowest amount of LTP, whereas ENS had the highest. SNS and EWS had similar levels of LTP, which were in between the SWS and ENS groups. Corticosterone blood levels measured by an ELISA showed significant increases in the stressed groups compared to the non-stressed groups. The radial arm maze showed that both groups of exercise mice made fewer reference memory errors the second week of testing compared to the sedentary groups. RT-qPCR determined that brain-derived neurotrophic factor (BDNF) and corticoid and dopamine 5 receptors were likely causing some of the memory changes.

No description available.

No description available.

Posttraumatic stress disorder is a debilitating anxiety disorder that can develop in the aftermath of a traumatic or life–threatening event involving extreme horror, intense fear or bodily harm. The disorder is typified by a symptom triad consisting of re–experiencing, hyperarousal and avoidance symptoms. Approximately 15–25% of trauma–exposed individuals go on to develop PTSD, depending on the nature and severity of the trauma. Although dysfunctional adaptive responses exist in multiple neurobiological pathways in the disorder, e.g. glutamate, GABA, glucocortocoids and serotonin, the noradrenergic system is particularly prominent and represents an important pharmacological target in attempts at preventing the development of PTSD posttrauma. However, current literature shows opposing and conflicting results regarding the effect of selective noradrenergic agents in memory processing, and the effect of modulation of selective noradrenergic receptors are spread over diverse protocols and paradigms of learning and fear also employing different strains of animals. Fear conditioning is a behavioural paradigm that uses associative learning to study the neural mechanisms underlying learning, memory and fear. It is useful in investigating the underpinnings of disorders associated with maladaptive fear responses. Performing fear conditioning experiments with the aim of applying it to an animal model of PTSD, and relating these behavioural responses to a defined neural mechanism, will assist both in the elucidation of the underlying pathology of the disease, as well as the development of more effective treatment. This project has set about to re–examine the diverse and complex role of noradrenergic receptors in the conditioned fear response with relevance to PTSD. To the best of my knowledge, this study represents the first attempt at studying a range of noradrenergic compounds with diverse actions and their ability to modify conditioned fear in a single animal model. This work thus introduces greater consistency and comparative relevance not currently available in the literature, and will also provide much needed pre–clinical evidence in support of treatment strategies targeting the noradrenergic system in the prevention of PTSD posttrauma. The first objective of this study was to set up and validate a passive avoidance fear conditioning protocol under our laboratory conditions using the Gemini Avoidance System. The noradrenergic system plays a prominent role in memory consolidation and fear conditioning, while administration of –adrenergic blockers, such as propranolol, have been shown to abolish learning and fear conditioning in both humans and animals. Propranolol has also demonstrated clinical value in preventing the progression of acute traumatic stress syndrome immediately posttrauma to full–blown PTSD. To confer predictive validity to our model, the centrally active –adrenergic antagonist, propranolol, and the non–centrally acting –adrenergic antagonist, nadolol, were administered to Wistar rats after passive avoidance fear conditioning training in the Gemini Avoidance System. Wistar rats were used because of their recognised enhanced sensitivity to stress. Evidence from this pilot study confirmed that propranolol 10 mg/kg significantly inhibits the consolidation of learned fear in rats, whereas nadolol is ineffective. This effectively validated our protocol and the apparatus for further application in this study and also confirmed the importance of a central mechanism of action for –adrenoceptor blockade in the possible application of these drugs in preventing the development of PTSD posttrauma. The second objective of this study was to investigate the role of 1–, 2–, 1–, and 2–receptors in a conditioned fear passive avoidance paradigm. This was done in order to investigate how selective pharmacological modulation of these receptors may modify the conditioned fear response, and whether any of these receptor systems might exert opposing effects in passive fear conditioning. Various centrally active noradrenergic agents were employed over a 3–tiered dose response design, including the 1–antagonist, prazosin, the 2–agonist, guanfacine, the 2–antagonist, yohimbine, the 1–antagonist, betaxolol and the 2–antagonist ICI 118551. The effect of post–exposure administration of these drugs on conditioned fear was compared to that of propranolol 10 mg/kg. Selected doses of betaxolol (10 mg/kg) and ICI 118551 (1 mg/kg) attenuated fear conditioning to an extent comparable to propranolol, as did prazosin (0.1 mg/kg). Yohimbine tended to boster fear learning at all doses tested, albeit not significantly, while guanfacine did not produce any significant effect on memory retention at any of the doses studied. This latter observation was surprising since yohimbine tended to bolster fear conditioning while earlier studies indicate that 2–agonism impairs conditioned fear. Concluding, this study has conferred validity to our passive avoidance model and has provided greater insight into the separate roles of noradrenergic receptors in contextual conditioned fear learning. The study has provided supportive evidence for a key role for both 1– and 2–antagonism, as well as 1–antagonism, in inhibiting fear memory consolidation and hence as viable secondary treatment options to prevent the development of PTSD posttrauma. However, further study is required to delineate the precise role of the 2–receptor in this regard. / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2012.