RESUMO
It is well documented that the kidney plays a fundamental role in long-term arterial pressure regulation, and, as an endocrine organ, in the regulation of cardiovascular structure and functionality. In this study, the antihypertensive effect of long-term treatment (6 months) with placebo, verapamil, trandolapril, and a combination of the latter (verapamil plus trandolapril) was investigated in spontaneously hypertensive rats after half-renal-mass ablation. Arterial pressure was monitored during treatment and at the end, aortic structure and functionality were investigated. Trandolapril and the combination returned pressure to normal, whereas verapamil was less effective. All three treatment groups were similarly effective at reducing aortic medial hypertrophy, the wall-to-lumen ratio, and contraction evoked by potassium chloride and noradrenaline. Verapamil and veratran were more effective than trandolapril at reducing lamina media cross-sectional area. Trandolapril and the combination were more effective than verapamil at improving endothelial dysfunction.
Assuntos
Anti-Hipertensivos/uso terapêutico , Indóis/uso terapêutico , Vasodilatadores/uso terapêutico , Verapamil/uso terapêutico , Acetilcolina/farmacologia , Animais , Aorta , Pressão Sanguínea/efeitos dos fármacos , Feminino , Coração/efeitos dos fármacos , Coração/fisiologia , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Nefrectomia , Nitroprussiato/farmacologia , Norepinefrina/farmacologia , Cloreto de Potássio/farmacologia , Ratos , Ratos Endogâmicos SHR/cirurgia , Vasoconstrição/efeitos dos fármacosRESUMO
Carotid end-to-end microvascular anastomoses (MVA) were performed in 100 rats [50 spontaneously hypertensive (SHR); 30 spontaneously hypertensive stroke-prone (SHR-SP); and 20 normotensive controls (WKY)]. Animals were sacrificed at various intervals from immediately after anastomosis to 60 days after surgery, and vascular healing was studied with the scanning electron microscope. In this manner vascular healing in normotensive rats (WKY) could be compared with that in hypertensive rats (SHR and SHR-SP) with vascular disease. Results of this study suggest that vascular healing in hypertensive rats is delayed when compared with normotensive controls. Furthermore, suture material was occasionally incompletely endothelialized in hypertensive animals as long as 60 days after surgery and served as a potential source of emboli. Additionally, an increased susceptibility of hypertensive endothelium (SHR and SHR-SP) to clamp and needle injury was apparent. In spite of this, there was a 100% patency rate of all anastomoses performed, indicating that patency, per se, is unaffected by hypertensive vasculopathy.
