Estudamos se a sobrecarga salina leva ao aumento de neoíntima em vasos submetidos à lesão e avaliamos a participação do sistema renina-angiotensina neste processo. Usamos camundongos C57Bl6 machos tratados por 2 ou 12 semanas com NaCl 1% para beber ou água (grupos cont, sal2 e sal12), submetidos à lesão vascular. O grupo sal12 aumentou a lesão vascular e alterou a relação de fibras colágenas, com exacerbação de deposição colágena na lesão vascular, e a relação entre as angiotensinas II e (1-7) vasculares, com aumento de Ang (1-7) e sem redução de ang II após a lesão. Os resultados obtidos permitem concluir que a sobrecarga salina aumenta a neoíntima nas artérias com lesão e altera a relação entre angiotensinas II e (1-7) de forma possivelmente propiciar o aumento de relação íntima/média observado. / We studied if salt overload leads to an increase in neointima in injured arteries, and evaluate the involvement of the renin-angiotensin in this process. Were used C57Bl6 male mice treated for 2 or 12 weeks with 1% NaCl to drink or water (cont, sal2 sal12 groups) submitted to vascular injury. The group sal12 increased vascular injury and altered the relationship of collagen fibers, with exacerbation of collagen deposition in the vascular injury, and the relationship between vascular angiotensin II and (1-7), with an increase of Ang (1-7) and no reduction of Ang II after injury. The results indicate that salt overload increases neointima in injured arteries, and modifies the relationship between angiotensin II and (1-7), possibly providing the increase in intima/media ratio observed.

A doença cardiovascular (DCV) é a principal causa de mortalidade nos pacientes com doença renal crônica (DRC) e a hipertrofia de ventrículo esquerdo (HVE), a alteração mais freqüente. A remodelação cardíaca (RC) patológica ocorre em resposta a agressões como sobrecarga de volume ou de pressão e é influenciada por ativação neurohormonal, fatores locais, inflamação, isquemia, necrose e apoptose celular. Os miócitos são as principais células envolvidas na RC. Avaliamos o papel da hiperfosfatemia e do paratormônio (PTH) em animais urêmicos. Trinta e dois ratos Wistar machos foram submetidos à paratireoidectomia (PTX) e nefrectomia (Nx), com reposição contínua de PTH em concentração fisiológica (PTHf= 0,022 ug/100g/h) ou elevada (PTHe=0,11 ug/100g/h). Os animais sham (N=16) foram operados e recebiam infusão de veículo. Apenas o conteúdo de fósforo nas dietas era diferente, ou seja: pobre=0,2% (pP) ou rica em fósforo=1,2% (rP). Dividimos os animais em 6 grupos: Sham: Sham-pP (G1), Sham-rP (G2); PTX+Nx: PTHf-pP (G3), PTHf-rP (G4), PTHe-pP (G5), PTHe-rP (G6). Semanalmente determinamos o peso e a pressão arterial caudal. Creatinina, fósforo, cálcio PTH e hematócrito foram analisados. Após 8 semanas os animais foram sacrificados. A hipertrofia e fibrose miocárdicas foram analisadas com o sistema digital Leica. O peso do coração corrigido por 100g peso corporal foi maior nos grupos G5 e G6 e apresentou uma correlação positiva com hipertrofia e fibrose miocárdica. A hipertrofia e fibrose foram menores no G3, quando comparado aos grupos Nx. A hipertrofia miocárdica foi maior no G6, evidenciando o papel do P neste processo. A fibrose mocárdica ocorreu principalmente em subendocárdio e foi mais intensa no G6. Analisamos a expressão do fator transformador de crescimento (TGF-beta) e angiotensina II que foram mais intensas nos grupos G5 e G6. As lesões das artérias coronarianas foram avaliadas de forma semi-quantitativa e os animais G5 e G6 mostraram calcificações de camada média. A expressão da alfa-actina se correlacionou negativamente com as lesões coronarianas. Nossos resultados demonstraram a importância do fósforo e PTH na fisiopatologia da DCV, sendo necessário um melhor controle destes elementos para prevenção de mortalidade nos pacientes com DRC. / Cardiovascular disease (CVD) is the leading cause of mortality in patients with chronic kidney disease (CKD), and left ventricular hypertrophy (LVH) is the most common alteration. Pathologic cardiac remodeling (CR) occurs in response to injuries such as volume or pressure overload, and it is influenced by neurohormonal activation, local factors, inflammation, ischemia, necrosis and cellular apoptosis. Myocytes are the principal cells involved in CR. We evaluated the role of hyperphosphatemia and parathyroid hormone (PTH) in uremic animals. Thirty-two male Wistar rats were submitted to parathyroidectomy (PTX) and nephrectomy (Nx), with PTH continuous replacement in physiologic concentration (PTHf=0.022ug/100g/h) or elevated (PTHe=0.11ug/100g/h). The sham animals (N=16) were operated and received vehicle infusion. Only the phosphorus content in diets was different, that is: poor = 0.2% (pP) or rich in phosphorus = 1.2% (rP). We divided the animals into 6 groups: Sham: Sham-pP (G1), Sham-rP (G2); PTX+Nx: PTHf-pP (G3), PTHf-rP (G4), PTHe-pP (G5), PTHe-rP (G6). We determined the weight and caudal blood pressure weekly. Creatinine, phosphorus, PTH calcium and hematocrit were analyzed. After 8 weeks, the animals were sacrificed. Myocardial hypertrophy and fibrosis were analyzed using Leica digital system. The weight of the heart corrected for 100g body weight was greater in groups G5 and G6 and presented a positive correlation with myocardial hypertrophy and fibrosis. Hypertrophy and fibrosis were lower in G3, when compared to Nx groups. Myocardial hypertrophy was higher in G6, determining the role of P in this process. Myocardial fibrosis occurred mainly in subendocardium and was more intense in G6. We analyzed the expression of transforming growth factor (TGF-alfa) and angiotensin II, which were more intense in groups G5 and G6. Coronary artery lesions were evaluated semiquantitatively and G5 and G6 animals showed middle layer calcifications. Expression of alfa-actin correlated negatively with coronary lesions. Our results demonstrated the importance of phosphorus and PTH in the pathophysiology of CVD; therefore, a better control of these elements is required in order to prevent mortality in patients with CKD.

No description available.

Abstract not available

<p>This study addresses the issue of how to convert peptides into drug-like non- peptides with retained biological activities at peptide receptors. Angiotensin II (Asp-Arg-Val-Tyr-Ile-His-Pro-Phe, Ang II) was used as a model peptide. </p><p>Knowledge of the bioactive conformations of endogenous peptides is invaluable for the conversion of peptides into less peptidic analogues. Effectively constrained cyclic analogues, with retained pharmacological activities, may provide valuable information about the bioactive conformations of the peptide in question. </p><p>This thesis describes the development of synthesis for a number of protected, aldehyde-functionalized building blocks for standard solid phase peptide synthesis, and their use for the preparation of cyclic peptide analogues. The effect of variations in the side-chain lengths of the building blocks, on the outcome of the cyclizations was studied. Incorporation of a building block derived from L-aspartic acid afforded bicyclization towards the C-terininal end of the peptide, while for the corresponding L-glutamic acid derived building block, N-terminal directed bicyclization was achieved. A building block derived from L-2-aminoadipic acid was exploited for monocyclization furnishing <i>cis-</i> and <i>trans-</i> vinyl sulfide bridged peptide analogues. </p><p>The described cyclization methods have been applied to the synthesis of a number of conformationally constrained Ang II analogues, for which the pharmacological properties have been evaluated. Two of the Ang II analogues synthesized displayed high affinities and full agonist activities at the AT₁ angiotensin receptor, and have proven to be useful tools in the search for the bioactive conformation of Ang II.</p>

This study addresses the issue of how to convert peptides into drug-like non- peptides with retained biological activities at peptide receptors. Angiotensin II (Asp-Arg-Val-Tyr-Ile-His-Pro-Phe, Ang II) was used as a model peptide. Knowledge of the bioactive conformations of endogenous peptides is invaluable for the conversion of peptides into less peptidic analogues. Effectively constrained cyclic analogues, with retained pharmacological activities, may provide valuable information about the bioactive conformations of the peptide in question. This thesis describes the development of synthesis for a number of protected, aldehyde-functionalized building blocks for standard solid phase peptide synthesis, and their use for the preparation of cyclic peptide analogues. The effect of variations in the side-chain lengths of the building blocks, on the outcome of the cyclizations was studied. Incorporation of a building block derived from L-aspartic acid afforded bicyclization towards the C-terininal end of the peptide, while for the corresponding L-glutamic acid derived building block, N-terminal directed bicyclization was achieved. A building block derived from L-2-aminoadipic acid was exploited for monocyclization furnishing cis- and trans- vinyl sulfide bridged peptide analogues. The described cyclization methods have been applied to the synthesis of a number of conformationally constrained Ang II analogues, for which the pharmacological properties have been evaluated. Two of the Ang II analogues synthesized displayed high affinities and full agonist activities at the AT1 angiotensin receptor, and have proven to be useful tools in the search for the bioactive conformation of Ang II.

<p>Tulbaghia violacea Harv. (Alliaceae) is a small bulbous herb which belongs to the family, Alliaceae, most commonly associated with onions and garlic. In South Africa (SA), this&nbsp / herb has been traditionally used in the treatment of various ailments, including fever, colds, asthma, paralysis, hypertension (HTN) and stomach problems. The aim of this study&nbsp / was to evaluate the effect of methanol leaf extracts (MLE) of T. violacea on the blood pressure (BP) and heart rate (HR) in anaesthetized male spontaneously hypertensive rats / &nbsp / and to find out the mechanism(s) by which it acts. The MLE of T. violacea (5 - 150 mg/kg), angiotensin I (ang I, 3.1 - 100 &mu / g/kg), captopril (10 mg/kg), angiotensin II (ang II, 3.1 - 50&nbsp / g/kg), losartan (30 mg/kg), phenylephrine (0.01 &ndash / 0.16 mg/kg), prazosin (1 mg/kg), dobutamine (0.2 &ndash / 10.0 &mu / g/kg), propranolol (0.1 - 12.8 mg/kg), muscarine (0.16 -10 &mu / g/kg),&nbsp / and atropine (0.02 - 20.48 mg/kg) were administered intravenously into male spontaneously hypertensive rats (SHR) weighing between 300 g and 350 g and aged less than 5&nbsp / months. The MLE of T. violacea and/or the standard drugs were infused alone, simultaneously, or separately into each animal. The BP and HR were measured via a pressure&nbsp / transducer connecting the femoral artery and the Powerlab. The vehicle (0.2 mls of a mixture of dimethylsulfoxide and normal saline), T. violacea (60 mg/kg) and captopril (10&nbsp / mg/kg) were injected intraperitoneally into some SHR for 21 days to investigate the chronic effect of these agents on plasma levels of aldosterone. The mean change, the mean&nbsp / of the individual percentage changes and the percentage difference (in mean) observed with each intervention was calculated and statistically analyzed using the Student&rsquo / s t test&nbsp / for significant difference (p &lt / 0.05). The Microsoft Excel software was used for statistical analysis. T. violacea significantly (p &lt / 0.05) reduced the systolic, diastolic, and mean&nbsp / arterial BP / and HR dose-dependently. In a dose-dependent manner, ang I, ang II, phenylephrine significantly (p &lt / 0.05) increased the BP, while propranolol, muscarine and&nbsp / atropine reduced the BP. The increases in BP due to dobutamine were not dose-dependent. In a dose dependent manner, phenylephrine and propranolol reduced the HR, while dobutamine increased the HR. The effect of ang I, ang II, muscarine and atropine on HR were not dose-dependent / with both increases as well as decreases observed with ang&nbsp / I, and II and atropine, while decreases were seen with muscarine. Captopril produced&nbsp / significant (p &lt / 0.05) reduction in BP which were not associated with any change in HR. The co-infusion of ang I with the MLE produced significant (p &lt / 0.05) reduction in BP, which were not associated with significant changes in HR. The co-infusion of ang II with the&nbsp / MLE did not produce any significant changes in BP or HR when compared to the infusion of the standard drug alone. The co-infusion of phenylephrine with the MLE did not&nbsp / produce any significant change in BP or HR when compared to the values obtained with the infusion of the standard drug alone, in both the absence and presence of prazosin.&nbsp / The co-infusion of dobutamine with T. violacea produced siginificant (p &lt / 0.05) increases in DBP which were associated with significant (p &lt / 0.05) reductions in HR, when&nbsp / compared to the values obtained with the infusion of the standard drug alone. Theco-infusion of atropine with the MLE did not produce any significant change in BP or HR when&nbsp / compared to the values obtained with the infusion of atropine alone. However, the infusion of T. violacea, 20 minutes after pre-treating animals with atropine (5.12 mg/kg) lead to&nbsp / dose dependent significant (p &lt / 0.05) increases in BP, which were associated with dose-dependent increases in HR. The chronic treatment of animals with T. violacea or&nbsp / captropril produced (a) signicant (p &lt / 0.05) reductions in the plasma levels of aldosterone when compared to the values obtained in the vehicle-treated group, (b) produced&nbsp / signifiant (p &lt / 0.05) reduction in BP in the captopril treated group when compared to the vehicle-treated, (c) did not produce any signficant change in BP in the T. violacea-treated&nbsp / group when compared to the vehicle-treated group and (d) did not produce any signifiant change in HR or body weight in any of the groups. The result obtained in this study&nbsp / suggests that T. violacea reduced BP and HR in the SHR. Secondly, the BP and HR reducing effect of the MLE may involve a) the inhibition of the ACE, b) the inhibition of the &beta / 1&nbsp / adrenoceptors, c) the stimulation of the muscarinic receptors and d) the reduction of the levels of aldosternone in plasma. The results also&nbsp / suggest that the MLE may not act&nbsp / through the angiotensin II receptors or the &alpha / 1 adrenergic receptors.&nbsp / </p>

Η υπέρταση αποτελεί έναν από τους πλέον σημαντικότερους παράγοντες στην αύξηση των καρδιαγγειακών επεισοδίων τα οποία ευθύνονται περίπου για το ήμισυ των θανάτων στους ενηλίκους. To σύστημα ρενίνης-αγγειοτενσίνης (RAS), διαδραματίζει καθοριστικό ρόλο στη ρύθμιση της συστολικής και της διαστολικής πίεσης και για αυτό το λόγο η αναστολή του έχει αποτελέσει φαρμακολογικό στόχο για τη θεραπεία της υπέρτασης. Οι μη πεπτιδικοί ΑΤ1 ανταγωνιστές της Αγγειοτενσίνης ΙΙ αντιπροσωπεύουν τη νεότερη γενιά αντιϋπερτασικών φαρμάκων. Επιδρούν στο τελικό στάδιο του RAS, αποτελώντας μία αποτελεσματική θεραπευτική προσέγγιση της υπέρτασης. Με βάση το Losartan, τον πρώτο μη πεπτιδικό ΑΤ1 ανταγωνιστή της Αγγειοτενσίνης ΙΙ που κυκλοφόρησε στην αγορά το 1995, σχεδιάστηκαν δραστικότεροι και εκλεκτικότεροι ανταγωνιστές με παρατεταμένη βιολογική δράση. Στόχος της παρούσας ερευνητικής εργασίας και έχοντας ως βάση τα χαρακτηριστικά του Losartan, ήταν η σύνθεση μονοαλκυλιωμένων παραγώγων με βάση είτε το 2-βουτυλοϊμιδαζόλιο (ανάλογο 1),, είτε το 4-βουτυλοϊμιδαζόλιο (ανάλογο 2). Συγκεκριμένα, φέρουν τα ακόλουθα δομικά χαρακτηριστικά:  Ένα ιμιδαζολικό δακτύλιο υποκατεστημένο με την n-βουτυλ-ομάδα είτε στη θέση 2 (1), είτε στη θέση 4 (2) του ιμιδαζολίου, καθώς σύμφωνα με τη βιβλιογραφία η βουτυλ-ομάδα αυτή αλληλεπιδρά με τη λιπόφιλη περιοχή του υποδοχέα και διαθέτει το βέλτιστο μήκος, με απώτερο στόχο την εμφάνισης ή όχι βιολογικής δράσης.  Τη [2´-(2Η-τετραζολ-5-υλ)διφαινυλ-4-υλ]μεθυλ-ομάδα. / Hypertension is one of the most important factors resulting in the increase of cardiovascular episodes, which are responsible for approximately half of all deaths in adults. The Renin-Angiotensin System (RAS) plays a defining role in the regulation of systolic and diastolic pressure and its inhibition has been a pharmacological goal in the treatment of hypertension. Non peptide AT1 receptor Angiotensin II antagonists represent the latest generation of antihypertensive drugs. They interfere in the final blockade site of RAS thus being an effective therapeutic approach towards treating hypertension. Losartan was the first non peptide AT1 receptor angiotensin II antagonist to become available in the market in 1995. Using Losartan as a base, more potent and selective antagonists with prolonged biological action were designed. The goal of this thesis and using the characteristics of Losartan as basis, was the synthesis of monoalkylated products based on either 2-butylimidazole (analogue 1) or 4-butylimidazole (analogue 2). Το be more specific they had the following structural characteristics:  An imidazole ring substituted with the n-butyl group either at position 2 (1) or at position 4 (2) of imidazole, since according to existing literature this butyl group interacts with the lipofile area of the receptor and has the ideal size for the appearance of biological action.  The [2´-(2Η-tetrazol-5-yl)biphenyl-4-yl]methyl-group.

Η υπέρταση αποτελεί έναν από τους σημαντικότερους παράγοντες που αυξάνει τα καρδιαγγειακά επεισόδια τα οποία ευθύνονται περίπου για το ήμισυ των θανάτων στους ενηλίκους. To σύστημα ρενίνης-αγγειοτασίνης-αλδοστερόνης (RAAS) διαδραματίζει καθοριστικό ρόλο στη ρύθμιση της συστολικής και της διαστολικής πίεσης και η αναστολή του έχει αποτελέσει φαρμακολογικό στόχο για τη θεραπεία της υπέρτασης. Οι μη πεπτιδικοί ΑΤ1 ανταγωνιστές της Αγγειοτασίνη ΙΙ αντιπροσωπεύουν τη νεότερη γενιά αντιϋπερτασικών φαρμάκων. Επεμβαίνουν στο τελικό στάδιο του RAAS αποτελώντας μία αποτελεσματική θεραπευτική προσέγγιση της υπέρτασης. Με βάση το Losartan, τον πρώτο μη πεπτιδικό ΑΤ1 ανταγωνιστή της Αγγειοτασίνη ΙΙ που κυκλοφόρησε στην αγορά σχεδιάστηκαν δραστικότεροι και εκλεκτικοί ανταγωνιστές με παρατεταμένη βιολογική δράση. Στα πλαίσια της παρούσας ερευνητικής εργασίας έγινε σύνθεση διαλκυλιωμένων αναλόγων που φέρουν ως βάση τον ετεροκυκλικό ιμιδαζολικό δακτύλιο υποκατεστημένο στις θέσεις -4, -5. / Hypertension is one of the most important factors resulting in the increase of cardiovascular episodes, which are responsible for approximately half of all deaths in adults. The Renin-Angiotensin-Aldosterone System (RAAS) plays a defining role in the regulation of systolic and diastolic pressure and its inhibition has been a pharmacological goal in the treatment of hypertension. Non peptide AT1 receptor Angiotensin II antagonists represent the latest generation of antihypertensive drugs. They interfere in the final blockade site of RAAS thus being an effective therapeutic approach towards treating hypertension. Losartan was the first non peptide AT1 receptor angiotensin II antagonist to become available in the market. Using Losartan as a base, more potent and selective antagonists with prolonged biological action were designed. In the context of this thesis, the synthesis of dialkylated analogues based on the 4, 5 trisubstituted heterocyclic imidazole ring is described.

Objective: To evaluate the tendencies of utilization of Angiotensin converting enzyme inhibitors and Angiotensin II receptors antagonists in Lithuania during 2005-2007 years. Methods: MEDLINE database was searched to identify and evaluate all literature relating to pharmacokinetic and pharmacodynamic characteristics of Angiotensin converting enzyme inhibitors and Angiotensin II antagonists. Utilization data of Angiotensin converting enzyme inhibitors (plain and combinations) and Angiotensin II antagonists (plain and combinations) in Lithuania over three years (2005 – 2007) period were obtained from SoftDent, JSC database. The retail prices of agents acting on the Renin-angiotensin-aldosterone selected from Reimbursed Medical Products Reference Prices Lists of 2005, 2006, 2007 years. Drugs were classified according to the Anatomic Therapeutic Chemical system and use was quantified in terms of defined daily doses (ATC/DDD). Consumption of Angiotensin converting enzyme inhibitors (plain and combinations) and Angiotensin II antagonists (plain and combinations) was calculated by DDD methodology and expressed as DDD per 1.000 inhabitants per day. Pharmacoeconomic calculations were done according to cost minimization and reference price methodologies. Results: According to meta-analysis, number of included studies (69 publications) that evaluated various treatment and head-to-head efficacy comparisons found in literature no consistent differential effects of ACEIs versus ARBs on... [to full text] / Tikslas: atlikti Angiotenziną konvertuojančių fermentų inhibitorių ir Angiotenzino II antagonistų suvartojimo tendencijų Lietuvoje analizę 2005 – 2007 metais. Metodai: Duomenys apie Angiotenziną konvertuojančio fermento inhibitorių ir Angiotenzino II antagonistų farmakokinetines ir farmakodinamines savybes buvo surinkti iš MEDLINE elektroninių duomenų šaltinių. Duomenys apie AKF inhibitorių (paprastų ir sudėtinių) ir Angiotenzino II antagonistų (paprastų ir sudėtinių) suvartojimą Lietuvoje per 2005 – 2007 metus gauti iš UAB SoftDent duomenų bazės. Renino-angiotenzino-aldosterono sistemą veikiančių vaistų mažmeninės kainos išrinktos iš Lietuvos kompensuojamų vaistinių preparatų 2005, 2006, 2007 metų kainynų. Vaistai buvo suklasifikuoti pagal anatominę terapinę cheminę (ATC) klasifikaciją. AKFI inhibitorių (paprastų ir sudėtinių) ir Angiotenzino II antagonistų (paprastų ir sudėtinių) suvartojimas buvo vertinamas pagal apibrėžtos dienos dozės (DDD – daily defined dose) metodiką, o duomenys įvertinti pagal DDD skaičių, tenkantį 1000 gyventojų per vieną dieną. AKF inhibitorių (paprastų ir sudėtinių) ir Angiotenzino II antagonistų (paprastų ir sudėtinių) farmakoekonominei analizei atlikti buvo taikytas kainų mažinimo bei standartinės kainos nustatymo metodai. Rezultatai: Vadovaujantis metaanalizių, įvairių klinikinių tyrimų 69 publikacijomis bei išsamia AKF inhibitorių ir Angiotenzino II antagonisų efektyvumo palyginimo analize galima teigti, kad šių vaistų grupių poveikis... [toliau žr. visą tekstą]