Efeito do bay 41-2272, na pressão arterial de ratos sob tratamento cronico com inibidor da sintese de oxido nitrico

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Recently, the compound BAY 41-2272, a pyirazolopyridine derivative, was described as an specific GCs activator by a mechanism that is independent of NO (Straub et al. ,2001; Stasch et al., 2001). In vitro experiments demonstrated that BAY 41-2272 stimulates potently sGC at concentrations of 0.1 nM to 100 Nrn, this effeet is potentiated in the presence of NO donors licke 2-(N, N-diethylamino )-diazendate-2-oxide (DEA)/NO (Staeh et. al., 2001). In studies using enzymes were the harm group was removed, BAY 41-2272 did not activate the harm-free enzyme demonstrating that BAY 41-2272 aetives sGC by an NO-independent, but heme-dependent mechanism (Stach et al., 2001). It is observed that the inhibition of the synthesis of nitric oxide is responsible, largely, for the appearance of pathological processes, mainly in the cardiac system. In this sense, this research seeks mainly to investigate the effects of BAY 41-2272 (BAY 41-2272, Bayer AG-Germany, a potent NO-independent stimulator of sGC) in rats, in a physiologie point of view and in a process physiopathological process (hypertension), evaluating the importance of this stimulation way in the presence of the pathology. For this purpose, WistarlUni S.P.F.(250 to 350g) obtained from the Center of Bioterism of the State University of Campinas (CEMIB - UNlCAMP), were housed in individual cages and kept in ventilated shelves (ALESCO) under controlled conditions of light (l2h light dark eycle) and temperature (22°C). The mean arterial blood pressures (MABP) were collected during 90 seconds two times a week for eight weeks. Rats were equipped with implantable radiotelemetry, and a data acquisition system (Data Science Inc., St. Paul, MN, USA), comprising a chronically implantable transducer/transmitter unit fluid-filled catheter. The transmitter was implanted into the peritoneal cavity and the descending aorta, affixed to the inner peritoneal wall. The animals were divided in four experimental groups as follow: 1) Control receiving 1 ml of DMSO 80% per day; 2) L-NAME, receiving L-NAME, alone (20mg/rat per day), 3) BAY 41-2272, reeeiving alone (lOmglkg per day); 4) L-NAME + BAY 41-2272, receiving concomitantly L-NAME (20mg/rat per day) and BAY 41-2272 (10mglkg per day). L-NAME was dissolved in the drinking autoclavated water daily drunk by the rats, BAY 41-2272 was dissolved in 80% of DMSO and administered by gavages. The experiments were performed for up to 8 weeks. The results obtained showed that BAY 41-2272 reduces significantly the arterial hypertension induced by chronic treatment with L-NAME, as well the weight ofthe heart and of the left ventricle and the cardiomyocite injured area. Only animals had receiving BAY 41-2272 showed an increase in the heart rate that can be characterized by a compensatory mechanism in function of reduction of the arterial pressure in these animals

ASSUNTO(S)

telemetria hipertensão l-name

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