Effect of repeated administration of cadmium, captopril and its combination on plasma renin activity in rats

The effects of normal saline (1 ml kg-1, i.p. for 5 days), cadmium acetate (1 mg kg-1, i.p. for 5 days), captopril (20 mg kg-1, p.o. for 5 days), or captopril (20 mg kg-1, p.o. for 5 days) plus cadmium acetate (1 mg kg-1, i.p. for 5 days) on blood pressure (BP), heart rate (HR), plasma renin activity (PRA) and respiratory rate (RR) were examined in male Sprague-Dawley (S-D) rats. Repeated administration of cadimum acetate produced a hypertensive response (P < 0.01) without significant changes in PRA, HR or RR. The captopril group was associated with hypotension (P < 0.01) but again PRA, HR and RR were not significantly altered. In the group receiving captopril p.o. and cadmium i.p., BP rose significantly compared with captopril alone but PRA, HR, RR were not altered. Cadmium-induced hypertension cannot be obviously accounted for on its basis of augmented plasma or tissue renin angiotensin involvement.