Made available in DSpace on 2016-12-08T16:24:12Z (GMT). No. of bitstreams: 1 PGCV06MA009.pdf: 426326 bytes, checksum: 327decb1f96fe7fe958d4a50ff4d33d0 (MD5) Previous issue date: 2006-03-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study was designed to determine the hemodynamic and hemogasometric effects of the premedication with atropine in dogs submitted to chlorpromazine and dexmedetomidine administration under general anesthesia with isoflurane and kept in mechanic ventilation. Six dogs, weighing 17.9 ±3.9kg constituted the two groups of the study, with an interval of seven days between treatments. The animals were instrumentalized using isoflurane, proceeding the catheterization of the dorsal tibial artery and introduction of the SwanGanz catheter through the jugular vein. At the end of the instrumentalization the isoflurane concentration was adjusted to 1 CAM, initiating a 30 minute period of hemodynamic stabilization, when it was measured the parameters for the beginning of the protocol (M -15). It was administered atropine (0,04mg/kg/IM) (group atropine) or NaCl 0.9%/IM (saline group), and then M0 was measured 15 minutes after it. Immediately after this, chlorpromazine (0,5mg/kg) and dexmedetomidine (3μg/kg) were administered intravenously. Five minutes (M5) later all parameters were measured. From this moment, all evaluations were carried through 15 minutes intervals (M20, M35, M50, M65). Data were analyzed one-way ANOVA. Mean comparisons were made by SNK test and t pareado (p≤0,05). Intense bradycardia was observed in saline group and the systolic, diastolic and mean arterial pressure presented higher values in atropine group in relation to the values found in saline group five minutes after chlorpromazine and dexmedetomidine administration, however a lower cardiac index, mainly in M5, was observed in both groups. The total peripheral resistance index was higher in both groups from M5, being much higher and lasting in the atropine group. The left ventricular work index presented a superior value from M0 in atropine group in relation to the saline group. There were statistically significant differences in M20. The mechanical ventilation allowed the ventilatory stability and the hemogasometric parameters had no clinically significant differences. The results allowed concluding that chlorpromazine administration did not brighten up the severe and lasting arterial hypertension produced by the dexmedetomidine. The premedication with atropine kept the stability of the heart rate; however it aggravated the arterial hypertension produced by the alpha-2, increasing the cardiac work and the consumption of oxygen from myocardium / Objetivou-se avaliar os efeitos hemodinâmicos, hemogasométricos e cardiovasculares da prémedicação com atropina em cães tratados com clorpromazina e dexmedetomidina sob anestesia geral com isofluorano e mantidos em ventilação mecânica. Foram utilizados seis cães mestiços, pesando 17,9kg (±3,9), que respeitando-se intervalo de sete dias entre tratamentos, constituíram os dois grupos do estudo. Para instrumentação os animais foram anestesiados com isofluorano, procedendo-se a canulação da artéria tibial dorsal e introdução do cateter de Swan Ganz através da veia jugular direita. Ao término da instrumentação a concentração do isoflurano foi ajustada para 1 CAM, iniciando-se o período de estabilização hemodinâmica de 30 minutos, quando mensurou-se os parâmetros para início do protocolo experimental (M-15). Administrou-se, então, pela via intramuscular, atropina (0,04mg/kg) (grupo atropina) ou cloreto de sódio a 0,9% (grupo salina), após 15 minutos mensurou-se M0, quando subseqüentemente, aplicou-se por via intravenosa, em ambos os grupos, clorpromazina (0,5mg/kg) e dexmedetomidina (3μg/kg). Decorridos cinco minutos (M5) repetiram-se as mensurações. A partir deste momento as avaliações foram realizadas em intervalos de 15 minutos (M20, M35, M50, M65). A análise estatística das médias entre grupos foi realizada através do teste t pareado e a avaliação entre tempo dentro de cada grupo através de ANOVA de 1 via do teste Student Newman Keuls (p≤0,05). Observou-se intensa bradicardia no grupo salina e as pressões arteriais sistólica, diastólica e média apresentaram valores maiores no grupo atropina em relação aos encontrados no grupo salina a partir de M5, porém o índice cardíaco foi reduzido, principalmente em M5, nos dois grupos. No índice de resistência periférica total houve acréscimo a partir de M5 em ambos os grupos, sendo mais acentuado e duradouro no GAtropina. O índice do trabalho ventricular esquerdo apresentou valor superior a partir de M0 no grupo atropina em relação ao grupo salina, sendo a diferença estatisticamente significativa em M20. O controle da ventilação mecânica permitiu a estabilidade ventilatória e os parâmetros hemogasométricos não apresentaram diferença significativa clinicamente. Os resultados permitem concluir que a administração de clorpromazina não amenizou a hipertensão arterial severa e duradoura produzida pela dexmetomidina. A pré medicação com atropina manteve a freqüência cardíaca estável, porém agravou a hipertensão arterial produzida pelo alfa-2, aumentando o trabalho cardíaco e o consumo de oxigênio pelo miocárdio

Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2007.

Sildenafil, a selective phosphodiesterase type 5 (PDE5) inhibitor, is registered for the treatment of male erectile dysfunction (Viagra®) and pulmonary hypertension (Revatio®) in the United States. PDE5 is found in the endothelium of blood vessels in the penile corpus cavernosum, pulmonary vessels and also brain and other peripheral tissue. Sildenafil crosses the blood brain barrier, leading to side-effects such as headache and dizziness, as well as behavioural manifestations including depression, anxiety and aggression (Milman & Arnold, 2002). According to the Food and Drug Administration (2001), 12378 adverse events were reported after the use of sildenafil and 274 of these reports implicated sildenafil in neurologic, emotional, or psychological disturbances between January 1998 and 21 February 2001. In addition, in vivo studies in rats indicate that sildenafil has anxiogenic and stressogenic actions (Harvey et al., 2005; Volke et al., 2003). This is a clear indication that sildenafil influences neurological processes in the brain and may influence various signalling systems, which play major roles in the neural circuitry of the above-mentioned disturbances. Recent in vitro studies in our laboratory suggest that sildenafil may potentiate cholinergic muscarinic receptor signalling (Eager, 2004). These results suggest potential depressogenic actions, since an increase in acetylcholine is associated with depression-like symptoms (El- Yousef et al., 1973). It was therefore postulated that sildenafil may in fact possess antidepressant activity that is masked by a cholinergic-driven depressogenic activity. In a study conducted by Muller and Benkert in 2000, patients reported a decrease in depression-like symptoms when treated with sildenafil for erectile dysfunction. This implied that sildenafil not only had a direct effect on erectile function in about 50-80% of men with erectile dysfunction (Langtry and Markham, 1999; Padma-Nathan, 1999) but might also improve anhedonia and depression. The substantial correlation between the International Index of Erectile Function and Epidemiologic Studies-Depression Scale scores supported this assumption (Muller & Benkert, 2000). In addition, Raffaele et al. (2002) reported an indirect improvement in depressive-like symptoms in patients treated for erectile dysfunction with idiopathic Parkinson's disease. Aims: The current study investigated the behavioural and neuroreceptor properties of sildenafil in a rat model of depression. We also investigated a hypothesis that sildenafil displays antidepressant-like properties, but which are masked by its potentiation of the cholinergic system. Methods: The experimental layout was divided into three pilot studies. Pilot Study 1 validated the FST under our laboratory conditions, Sprague-Dawley rats received saline intraperitoneally (i.p.) for 7 days, whereafter half of the rats were pre-exposed to a 15 minute swim trial, while the remaining rats were not pre-exposed. All rats were then evaluated 24 hours later in the 5 minute scored swim trial. In Pilot Study 2 Sprague-Dawley rats were treated for 3, 7 or 11 days with vehicle (control) or 20 mg/kg fluoxetine to establish the time-dependency of the onset of antidepressant-like effects in a rat model of depression. We measured immobility in the rat forced swim test (FST), as well as changes in P-adrenergic receptor (P-AR) concentration in rat frontal cortex. In pilot study 3, rats were treated for 7 days with vehicle (control), 20 mg/kg fluoxetine, 10 mg/kg sildenafil, 1 mg/kg atropine or various combinations of these drugs. Again we employed the FST and measured cortical p-AR concentration. Results: In the FST pre-exposure to a 15 minute swim trial 24 hours before the scored swim trial significantly increased immobility. Fluoxetine inhibited this development of increased immobility in FST and decreased P-AR concentration after 7 and 11 days of treatment with fluoxetine, but not after 3 days. Seven days of treatment with atropine and sildenafil alone did not exert any changes in immobility in the FST or changes in p-AR concentration. However, a combination of atropine and sildenafil exerted a significant antidepressant-like behavioural effect, comparable with fluoxetine. Moreover, the combination of atropine and fluoxetine as well as the a triple combination of fluoxetine, sildenafil and atropine was superior to fluoxetine alone. Conclusion: Muscarinic cholinergic mechanisms mask the antidepressant-like properties of sildenafil in a rat model of depression. The antidepressant properties of the combination of sildenafil and atropine are comparable to that of fluoxetine in an animal model of depression. The combination of fluoxetine with atropine, and atropine and sildenafil enhances the antidepressant-like properties of fluoxetine. / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2007.

Sildenafil, a selective phosphodiesterase type 5 (PDE5) inhibitor, is registered for the treatment of male erectile dysfunction (Viagra®) and pulmonary hypertension (Revatio®) in the United States. PDE5 is found in the endothelium of blood vessels in the penile corpus cavernosum, pulmonary vessels and also brain and other peripheral tissue. Sildenafil crosses the blood brain barrier, leading to side-effects such as headache and dizziness, as well as behavioural manifestations including depression, anxiety and aggression (Milman & Arnold, 2002). According to the Food and Drug Administration (2001), 12378 adverse events were reported after the use of sildenafil and 274 of these reports implicated sildenafil in neurologic, emotional, or psychological disturbances between January 1998 and 21 February 2001. In addition, in vivo studies in rats indicate that sildenafil has anxiogenic and stressogenic actions (Harvey et al., 2005; Volke et al., 2003). This is a clear indication that sildenafil influences neurological processes in the brain and may influence various signalling systems, which play major roles in the neural circuitry of the above-mentioned disturbances. Recent in vitro studies in our laboratory suggest that sildenafil may potentiate cholinergic muscarinic receptor signalling (Eager, 2004). These results suggest potential depressogenic actions, since an increase in acetylcholine is associated with depression-like symptoms (El- Yousef et al., 1973). It was therefore postulated that sildenafil may in fact possess antidepressant activity that is masked by a cholinergic-driven depressogenic activity. In a study conducted by Muller and Benkert in 2000, patients reported a decrease in depression-like symptoms when treated with sildenafil for erectile dysfunction. This implied that sildenafil not only had a direct effect on erectile function in about 50-80% of men with erectile dysfunction (Langtry and Markham, 1999; Padma-Nathan, 1999) but might also improve anhedonia and depression. The substantial correlation between the International Index of Erectile Function and Epidemiologic Studies-Depression Scale scores supported this assumption (Muller & Benkert, 2000). In addition, Raffaele et al. (2002) reported an indirect improvement in depressive-like symptoms in patients treated for erectile dysfunction with idiopathic Parkinson's disease. Aims: The current study investigated the behavioural and neuroreceptor properties of sildenafil in a rat model of depression. We also investigated a hypothesis that sildenafil displays antidepressant-like properties, but which are masked by its potentiation of the cholinergic system. Methods: The experimental layout was divided into three pilot studies. Pilot Study 1 validated the FST under our laboratory conditions, Sprague-Dawley rats received saline intraperitoneally (i.p.) for 7 days, whereafter half of the rats were pre-exposed to a 15 minute swim trial, while the remaining rats were not pre-exposed. All rats were then evaluated 24 hours later in the 5 minute scored swim trial. In Pilot Study 2 Sprague-Dawley rats were treated for 3, 7 or 11 days with vehicle (control) or 20 mg/kg fluoxetine to establish the time-dependency of the onset of antidepressant-like effects in a rat model of depression. We measured immobility in the rat forced swim test (FST), as well as changes in P-adrenergic receptor (P-AR) concentration in rat frontal cortex. In pilot study 3, rats were treated for 7 days with vehicle (control), 20 mg/kg fluoxetine, 10 mg/kg sildenafil, 1 mg/kg atropine or various combinations of these drugs. Again we employed the FST and measured cortical p-AR concentration. Results: In the FST pre-exposure to a 15 minute swim trial 24 hours before the scored swim trial significantly increased immobility. Fluoxetine inhibited this development of increased immobility in FST and decreased P-AR concentration after 7 and 11 days of treatment with fluoxetine, but not after 3 days. Seven days of treatment with atropine and sildenafil alone did not exert any changes in immobility in the FST or changes in p-AR concentration. However, a combination of atropine and sildenafil exerted a significant antidepressant-like behavioural effect, comparable with fluoxetine. Moreover, the combination of atropine and fluoxetine as well as the a triple combination of fluoxetine, sildenafil and atropine was superior to fluoxetine alone. Conclusion: Muscarinic cholinergic mechanisms mask the antidepressant-like properties of sildenafil in a rat model of depression. The antidepressant properties of the combination of sildenafil and atropine are comparable to that of fluoxetine in an animal model of depression. The combination of fluoxetine with atropine, and atropine and sildenafil enhances the antidepressant-like properties of fluoxetine. / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2007.

No description available.

Made available in DSpace on 2016-06-02T19:22:59Z (GMT). No. of bitstreams: 1 5375.pdf: 1850581 bytes, checksum: 822cefb40c25ca3fd51f51b23edfe47b (MD5) Previous issue date: 2013-06-14 / Universidade Federal de Sao Carlos / Hypoxic bradycardia is a reflex response to hypoxia observed in most fish species studied so far. This reflex is initiated by the stimulation of O2 chemoreceptors and induced by an increase in the inhibitory vagal tonus. Despite of being well described and characterized, the hypothesis that hypoxic bradycardia improves the O2 transference from the ventilatory water to the gills still remain to be proved. The utilization of different methods to inhibit hypoxic bradycardia (vagotomy and atropinization) may have contributed to generate different cardiorespiratory responses, making this issue even more controversial. In this study the cardiorespiratory variables (heart frequency fH, metabolic rate - VO2 , O2 extraction from the ventilatory current EO2, gill ventilation - VG , breathing frequency fR, and ventilatory requirement - VG / VO2 ) were measured in the tambaqui, Colossoma macropomum, under normoxia and after 40 min of exposure to severe hypoxia (20 mmHg) and the 3 subsequent hours of recovery. Each fish was subjected to this protocol before (Control group), after atropine administration (A group) and after vagotomy (V group). Under hypoxia the fish of control group displayed the characteristic hypoxic bradycardia (reduction of 56% in fH) with hyperventilation (increases of 96% in fR and 650% in VG ). This hyperventilation was probably responsible by the decrease in EO2 (65%) and, consequently, in the VO2 (62%), resulting in an increase of 1800% in the VG / VO2 . The beginning of the recovery period was characterized by an elevated VO2 (~200% above the normoxic values) accompanied by tachycardia (50.6 bpm) and gradual recovery of EO2, fR, VT and VG . Atropine and vagotomy elevated the fH in normoxia (from 32.0 ± 1.7 to 77.8 ± 4.1 and 80.6 ± 5.8 bpm), indicating a high basal vagal tone. In these two groups the fH remained constant during the experimental time course. This evidenced that the post-hypoxia tachycardia probably occurred as a consequence of a reduction in the cholinergic tonus. The groups control, atropinized and vagotomized did not show significant differences in EO2, VO2 and the other respiratory variables analyzed in any protocol. This results point out that hypoxic bradycardia does not improve the O2 transference to the gills, independently of the method employed to abolish the bradycardic reflex. Therefore, other hypotheses on the hypoxic bradycardia must be investigated in this species. / A bradicardia hipóxica é uma resposta reflexa à hipóxia presente na maioria dos teleósteos. Este reflexo é induzido por um aumento no tônus vagal inibitório e iniciado pela estimulação de quimiorreceptores de oxigênio (O2). Apesar de muito descrita e bem caracterizada, a hipótese de que esta redução na frequência cardíaca (fH) melhore a transferência de O2 pelas brânquias ainda não foi comprovada. A utilização de diferentes métodos para inibir a bradicardia hipóxica (vagotomia e atropinização) pode ter contribuído para gerar respostas cardiorrespiratórias diversas e tornar esta questão ainda mais controversa. Neste trabalho foram avaliadas as variáveis cardiorrespiratórias (fH; taxa metabólica VO2 ; extração de O2 da corrente ventilatória EO2; ventilação branquial VG ; frequência respiratória fR; volume ventilatório VT e necessidade ventilatória VG / VO2 ) do tambaqui, Colossoma macropomum, em normóxia, após 40 min de hipóxia severa (20 mmHg) e durante 3 h de recuperação subsequente. Cada animal foi submetido a este protocolo antes (Ctr), após administração de atropina (A) e após vagotomia (V). Em hipóxia os animais Ctr apresentaram a característica bradicardia hipóxica (redução de 56% na fH) com aumentos na fR (~96 %) e VT (~275 %) elevando muito a VG (~650 %). Esta alta VG , provavelmente foi responsável pela queda significativa na EO2 (65%), consequentemente reduzindo a VO2 (62 %) e aumentando muito a VG / VO2 (1800 %) em hipóxia. O início do período de recuperação do grupo Ctr foi caracterizado por elevada VO2 (~200 % acima dos valores de normóxia), acompanhada de taquicardia (50,6 bpm) e recuperação gradual da EO2, fR, VT e VG . A atropina e a vagotomia elevaram a fH em normóxia (de 32,0 ± 1,7 para 77,8 ± 4,1 e 80,6 ± 5,8 bpm) indicando um alto tônus vagal de repouso, sendo que nestes dois grupos a fH permaneceu constante em todos os tempos experimentais evidenciando que a taquicardia póshipóxia foi, provavelmente, consequência de uma redução no tônus colinérgico. Na EO2, VO2 e demais parâmetros respiratórios analisados não houve diferenças entre os grupos Ctr, A e V, em nenhum momento do protocolo. Estes resultados demonstram que a bradicardia hipóxica, possivelmente, não melhora a transferência de O2 pelas brânquias de tambaqui independente do método de abolição do reflexo bradicárdico. Portanto, outras hipóteses sobre a função da bradicardia hipóxica, como na proteção do miocárdio, devem ser investigadas nesta espécie.

Les personnes âgées souffrant de troubles neurocognitifs majeurs (TNCM) seraient davantage vulnérabilisées par les maladies chroniques et plus exposées à la prise concomitante de médicaments (polypharmacie). Elles seraient par conséquent plus à risque d'issues de santé défavorables associées à cette polypharmacie. Les psychotropes sont souvent utilisés pour atténuer les symptômes comportementaux et psychologiques de la démence, bien que leur efficacité n'ait pas été démontrée avec évidence et malgré les risques d'effets indésirables qu'ils présentent. La prise de médicaments anticholinergiques soulève également des préoccupations en raison de leur effet cognitif potentiel. L'objectif de l'étude est d'établir, chez les aînés vivant en collectivité entre 2015 et 2018, si une variation du nombre de médicaments réclamés, et plus spécifiquement des médicaments psychotropes et anticholinergiques, est observée suite au diagnostic d'un TNCM. Nous avons réalisé une étude de cohorte populationnelle rétrospective à l'aide des données administratives du Système intégré de surveillance des maladies chroniques du Québec (SISMACQ), dans le but de comparer l'usage de médicaments l'année précédant et l'année suivant le diagnostic. Le groupe TNCM (n= 12 167) inclut les personnes âgées de 66 ans et plus ayant reçu un diagnostic de TNCM en 2016-2017. Des aînés sans atteinte cognitive ont été sélectionnés afin de former le groupe contrôle (n= 88 729), qui permet de tenir compte de l'effet du temps sur l'usage de la médication. La variation du nombre de médicaments réclamés suite au diagnostic, ainsi que celle de la prévalence de l'utilisation de médicaments psychotropes et anticholinergique sont été estimées à l'aide de la méthode des doubles différences. Dans le groupe TNCM, le nombre moyen de médicaments réclamés est de 9,5 l'année précédant le diagnostic et augmente de 1,25 au cours de l'année suivant le diagnostic, en excluant les traitements anti-Alzheimer. En comparaison, 8,5 médicaments sont réclamés en moyenne la première année dans le groupe contrôle et ce nombre augmente de 0,45 médicament l'année suivante. La différence moyenne ajustée entre ces variations est de 0,81 (IC[indice 95%]: 0,74; 0,87) médicaments. Une hausse de la prévalence de l'utilisation de certaines classes de médicaments est observée suite au diagnostic : antipsychotiques : 13,2 % (12,5; 13,9); antidépresseurs : 7,1 % (6,5; 7,7); médicaments anticholinergiques : 3,8 % (3,1; 4,6). Aucune cessation de classe de médicaments particulière n'a été mise en évidence lors de nos analyses. L'établissement du diagnostic d'un TNCM est associé à une hausse de la polypharmacie au cours de l'année subséquente. Cette variation est en partie causée par une augmentation de la prescription d'antipsychotiques et d'antidépresseurs. / Older adults with major neurocognitive disorders (MNCD) are more affected by chronic diseases and more exposed to polypharmacy. They are therefore at greater risk of adverse health outcomes associated with concomitant use of medications. Psychotropic medications are often prescribed to alleviate the behavioral and psychological symptoms of dementia, although their efficacy has not been clearly demonstrated and despite the risks of adverse effects. There are also concerns about the use of anticholinergic medications because of their potential cognitive effect. The objective of the study is to determine whether a change in the number of medications claimed, and more specifically psychotropic and anticholinergic medications, is observed following the diagnosis of a MNCD, among community-dwelling older adults between 2015-2018. We conducted a retrospective population-based cohort study using administrative data from the Quebec Integrated Chronic Disease Surveillance System (QICDSS) to compare medications claimed in the year before and the year after diagnosis. The MNCD group (n= 12,167) included adults aged 66 years and older with a diagnosis of MNCD in 2016-2017. Older adults without MNCD were selected to form the control group (n=88,729), which allows for the effect of time on medication use. The change in the number of medications claimed following diagnosis, as well as the change in the prevalence of use of psychotropic and anticholinergic medications, was estimated using the difference-in-difference method. In the MNCD group, the average number of medications claimed was 9.5 in the year before the diagnosis and increased by 1.25 during the year following diagnosis, excluding anti-Alzheimer's treatments. In the control group, the average number of medications was 8.5 and an increase of 0.45 medication was observed during the following year. The adjusted mean difference between these variations was 0.81 (95% CI: 0.74; 0.87) medication. Using the difference-in-difference method, we observed an increase in the prevalence of use of antipsychotics [13.2% (12.5; 13.9)], antidepressants [7.1% (6.5; 7.7)], and anticholinergic medications [3.8% (3.1; 4.6)]. No significant pattern of medication discontinuation was identified in our analyses. The diagnosis of MNCD is associated with an increase of polypharmacy in the subsequent year. This change is driven in part by an increase of antipsychotic and antidepressant claims.

Há muitos agentes terapêuticos comercializados sob forma racêmica. Os enantiômeros podem apresentar diferenças significativas nos perfis farmacocinético e farmacodinâmico. O uso do enantiômero puro em formulações farmacêuticas pode resultar em melhor ajuste de dose e menos efeitos adversos. A atropina, um alcalóide natural da Atropa belladonna, é a mistura racêmica de l-hiosciamina e d-hiosciamina. Este fármaco é principalmente utilizado para dilatar a pupila e como um antiespasmódico. Para quantificar estes enantiômeros, foram desenvolvidos métodos analíticos utilizando a cromatografia líquida de alta eficiência (CLAE) com as fases estacionárias quirais Chiralcel-OD® e Chiral-AGP®. Para quantificar estes enantiômeros em soluções oftálmicas, foi realizada a validação com sucesso de um método por CLAE, empregando uma coluna Chiral-AGP®, a 20°C. A fase móvel foi uma solução tampão fosfato (contendo 10 mM de 1-octanosulfonato de sódio e 7,5 mM de trietilamina, ajustada para pH 7,0 com ácido fosfórico) e acetonitrila (99:1 v/v). A vazão foi de 0,6 mL/min, com detecção ultravioleta em 205 nm. No intervalo de concentração de 14,0 µg/mL a 26,0 µg/mL, o método é linear (r > 0,9999), exato (100,1% - 100,5%) e preciso (RSDsistema ≤ 0,6%; RSDintra-dia ≤ 1,1%; RSDentre-dias ≤ 0,9%). O método é específico e os testes de validação asseguram que as soluções de padrão e amostra são estáveis até 72 horas. O planejamento fatorial assegura a robustez com variação de ±10% nos componentes da fase móvel e 2°C na temperatura da coluna. / There are many therapeutic agents commercialized under racemic form. The enantiomers can show significant differences in the pharmacokinetic and pharmacodynamic profiles. The use of pure enantiomer in pharmaceutical formulations can result in better adjustment of dose and less adverse effects. Atropine, an alkaloid of the Atropa belladonna, is a racemic mixture of l-hyoscyamine and d-hyoscyamine. This drug is mainly used to dilate the pupil and as an antispasmodic agent. To quantify these enantiomers analytical methods were developed, using high performance liquid chromatography (HPLC) with chiral stationary phases Chiralcel OD® and Chiral AGP®. To quantify these enantiomers in ophthalmic solutions the validation of a HPLC method was performed using a Chiral AGP® column at 20°C. The mobile phase consisted of a buffered phosphate solution (containing 10 mM 1-octanesulfonic acid sodium salt and 7.5 mM triethylamine, adjusted to pH 7.0 with ortho-phosphoric acid) and acetonitrile (99:1 v/v). The flow rate was 0.6 mL/min, with ultraviolet detection at 205 nm. In the concentration range from 14.0 mg/mL to 26.0 mg/mL, the method is linear (r > 0.9999), exact (100.1% - 100.5%) and precise (RSDsystem ≤ 0.6%; RSDintra-day ≤ 1.1%; RSDinter day ≤ 0.9%). The method is specific and the validation tests assure that standard and sample solutions are stable for up to 72 hours. The factorial design assures the robustness with variation of ± 10% in the mobile phase components and 2°C of column temperature.

Há muitos agentes terapêuticos comercializados sob forma racêmica. Os enantiômeros podem apresentar diferenças significativas nos perfis farmacocinético e farmacodinâmico. O uso do enantiômero puro em formulações farmacêuticas pode resultar em melhor ajuste de dose e menos efeitos adversos. A atropina, um alcalóide natural da Atropa belladonna, é a mistura racêmica de l-hiosciamina e d-hiosciamina. Este fármaco é principalmente utilizado para dilatar a pupila e como um antiespasmódico. Para quantificar estes enantiômeros, foram desenvolvidos métodos analíticos utilizando a cromatografia líquida de alta eficiência (CLAE) com as fases estacionárias quirais Chiralcel-OD® e Chiral-AGP®. Para quantificar estes enantiômeros em soluções oftálmicas, foi realizada a validação com sucesso de um método por CLAE, empregando uma coluna Chiral-AGP®, a 20°C. A fase móvel foi uma solução tampão fosfato (contendo 10 mM de 1-octanosulfonato de sódio e 7,5 mM de trietilamina, ajustada para pH 7,0 com ácido fosfórico) e acetonitrila (99:1 v/v). A vazão foi de 0,6 mL/min, com detecção ultravioleta em 205 nm. No intervalo de concentração de 14,0 µg/mL a 26,0 µg/mL, o método é linear (r > 0,9999), exato (100,1% - 100,5%) e preciso (RSDsistema ≤ 0,6%; RSDintra-dia ≤ 1,1%; RSDentre-dias ≤ 0,9%). O método é específico e os testes de validação asseguram que as soluções de padrão e amostra são estáveis até 72 horas. O planejamento fatorial assegura a robustez com variação de ±10% nos componentes da fase móvel e 2°C na temperatura da coluna. / There are many therapeutic agents commercialized under racemic form. The enantiomers can show significant differences in the pharmacokinetic and pharmacodynamic profiles. The use of pure enantiomer in pharmaceutical formulations can result in better adjustment of dose and less adverse effects. Atropine, an alkaloid of the Atropa belladonna, is a racemic mixture of l-hyoscyamine and d-hyoscyamine. This drug is mainly used to dilate the pupil and as an antispasmodic agent. To quantify these enantiomers analytical methods were developed, using high performance liquid chromatography (HPLC) with chiral stationary phases Chiralcel OD® and Chiral AGP®. To quantify these enantiomers in ophthalmic solutions the validation of a HPLC method was performed using a Chiral AGP® column at 20°C. The mobile phase consisted of a buffered phosphate solution (containing 10 mM 1-octanesulfonic acid sodium salt and 7.5 mM triethylamine, adjusted to pH 7.0 with ortho-phosphoric acid) and acetonitrile (99:1 v/v). The flow rate was 0.6 mL/min, with ultraviolet detection at 205 nm. In the concentration range from 14.0 mg/mL to 26.0 mg/mL, the method is linear (r > 0.9999), exact (100.1% - 100.5%) and precise (RSDsystem ≤ 0.6%; RSDintra-day ≤ 1.1%; RSDinter day ≤ 0.9%). The method is specific and the validation tests assure that standard and sample solutions are stable for up to 72 hours. The factorial design assures the robustness with variation of ± 10% in the mobile phase components and 2°C of column temperature.

Nicotine exerts a therapeutic effect in ulcerative colitis (UC) but the mechanism underlying this effect, is not clear. However, this effect may imply that nicotine has some, as yet to be discovered, effect on the immune system. The aim of the work described in this thesis was to characterise the nicotinic acetylcholine receptors (nAChRs) on human peripheral blood lymphocytes in term of receptor subtype. To achieve this, a combination of radioligand binding assays, pharmacological and molecular biological techniques were used. The data obtained from the binding studies suggested that the presence of one binding site for (-)- nicotine on human peripheral blood lymphocytes with a Kd 15 ± 5.759 nM (1.5 ± 5.759 x 10-8 M) and Bmax 2253 ± 409 sites/cell. The competition studies showed that ligands competing with [3H]-(-)-nicotine were (-)-nicotine, epibatidine and α-bungarotoxin, while others ligands for nAChRs displaced radiolabelled nicotine in insignificant quantities. Thus, radioligand-binding experiments suggest that the binding site for nicotine on human peripheral blood lymphocytes is a nAChR containing α7 and possibly α4 or/and b2 containing nAChR subunits. No evidence was obtained to suggest the presence of a non-cholinergic nicotine receptor. Furthermore, considerable subject to subject variation in the specific binding of radiolabelled nicotine was observed. Because of this only tentative conclusions could be drawn from radioligand binding data. Polymerase chain reaction (RT-PCR) was then used to demonstrate mRNA for the subunits of nAChRs suggested by radioligand binding studies. Data obtained show that the human peripheral blood lymphocytes tested, expressed mRNAs for α4, α5, α7, β2 neuronal nAChRs subunits and β1 muscle nAChR subunit. Expression of the α5 mRNA subunit of nAChR was observed in the lymphocytes in each sample of lymphocytes tested. In contrast, the expression pattern of mRNAs for α4, α7, β1, and β2 mRNAs subunits of nAChRs, varied between individuals. Finally, Western blot analysis was used to confirm that mRNA expression resulted in the expression of protein for nAChR subunits in human peripheral lymphocytes using monoclonal antibodies against α4, α5, α7, and β2 nAChR subunits, which had been detected by RT-PCR. The results obtained from the Western blot analysis show that protein for α4, α5, and α7 nAChR subunits was expressed in most, but not all of the human peripheral blood lymphocyte samples tested and some of the bands obtained were faint. In contrast, protein for the β2 nAChR subunit was observed in a few samples tested and the bands were faint. From the results obtained in this study, it is possible to conclude that human peripheral blood lymphocytes may contain nAChRs with subunit compositions of α4β2, α4β2α5, and/or α7. However, further studies are necessary to show whether or not the single binding site for nicotine demonstrated by radioligand binding experiments is due to one or all of these nAChRs. Thus, the findings of the present study suggest the presence of nAChR on human peripheral blood lymphocytes. Nicotine and its effect may occur through these non- neuronal nAChRs mechanisms. Such a mechanism of action could account for the beneficial of nicotine in ulcerative colitis. Furthermore, a compound that acts on these receptors, but not on nAChRs found on other cells may have therapeutic utility in the treatment of inflammation.