RESUMO
The purpose was to determine the role of renal nerves in mediating the effects of antihypertensive treatment with L-arginine in a renovascular hypertension model. The 2K1C (two-kidney one-clip model) hypertensive rats were submitted to bilateral surgical-pharmacological renal denervation. The animals were subdivided into six experimental groups: normotensive control rats (SHAM), 2K1C rats, 2K1C rats treated with L-arginine (2K1C + L-arg), denervated normotensive (DN) rats, denervated 2K1C (2K1C + DN) rats, and denervated 2K1C + L-arg (2K1C + DN + L-arg) rats. Arterial blood pressure, water intake, urine volume, and sodium excretion were measured. The 2K1C rats exhibited an increase in the mean arterial pressure (MAP) (from 106 ± 3 to 183 ± 5.8 mmHg, P < 0.01), whereas L-arg treatment induced a reduction in the MAP (143 ± 3.4 mmHg) without lowering it to the control level. Renal nerve denervation reduced the MAP to normotensive levels in 2K1C rats with or without chronic L-arg treatment. L-arg and denervation induced increases in water intake and urine volume, and L-arg caused a significant natriuretic effect. Our results suggest that renal sympathetic activity participates in the genesis and the maintenance of the hypertension and also demonstrate that treatment with L-arg alone is incapable of normalizing the MAP and that the effect of such treatment is not additive with the effect of kidney denervation.
RESUMO
Os autores estudaram os efeitos do verapamil sobre a necrose hepática induzida pelo tetracloreto de carbono no camundongo. O tratamento de camundongos com verapamil, antes e após o C Cl4, protege o hepatócito da necrose: a necrose centrolobular foi menor nos camundongos tratados com verapamil. Um discreto efeito protetor foi observado quando os animais receberam uma só dose de verapamil, três horas antes ou três horas depois do C Cl4. É possível que o efeito protetor seja maior quando os níveis plasmáticos da droga säo mantidos por período maiores após a injeçäo de C Cl4
