[Renin-angiotensin-aldosterone system in chronic poisoning of rats with lead and cadmium].

The aim of the study was to investigate the impact of the chronic, single and combined exposure to lead and cadmium on renin-angiotensin-aldosterone system in rats. Experiments were performed on male Buffalo rats which were intragastrically administered of lead acetate in doses of 35 mg Pb/kg body weight once a week or in doses of 70 mg Pb/kg body wt. twice a week and/or cadmium chloride in doses of 20 mg Cd/kg body wt. once a week for a period of seven weeks. One day after the feeding was over, the following parameters were measured: plasma renin activity, activity of angiotensin converting enzyme, serum concentration of angiotensin II and aldosterone. Metal content (lead, cadmium and zinc) in blood, kidneys and brain was determined by means of atomic absorption spectrophotometry. No clinical signs of lead or cadmium toxicity effects were observed. Rats poisoned with different doses of lead displayed no changes in renin-angiotensin system. In comparison to controls, in rats poisoned with cadmium, decrease in the plasma renin activity, serum angiotensin II and aldosterone concentrations were observed, but it was associated with unchanged activity of angiotensin converting enzyme. The decrease in plasma renin activity depended on cadmium levels in blood. In comparison to rats given cadmium, in rats treated with cadmium and lead together the inhibitor of the renin-angiotensin-aldosterone systems was weaker, although cadmium was used in the same dose.