Inhibition of Aldosterone Secretion by Passive Transfer of Antirenin Antibodies to Dogs on a Low Sodium Diet ∗ †

Summary

Antirenin antibodies were infused intravenously and their effect on aldosterone secretion measured in 7 dogs fed 1 mEq of sodium per day and in 7 dogs fed 40 mEq of sodium per day. The mean aldosterone secretion rate in the dogs on the low sodium diet was significantly lower than that of 7 dogs on the same diet given control injections of protein. However, the mean aldosterone secretion rate in the dogs fed 40 mEq of sodium per day was in the same range as the rate in 7 dogs on the 40 mEq diet given control injections of protein. Furthermore, the value in the group of dogs on the low salt diet that were given the antirenin antibodies was in the same range as the values in these latter 2 groups. These results indicate that the increase in aldosterone secretion produced by restricting sodium intake is mediated via the renin-angiotensin system, while basal secretion on a more adequate sodium intake is independent of this system. There was a moderate increase in sodium excretion in the dogs receiving the antibodies, but a similar response also occurred in the dogs given control injections of plasma proteins. This suggests that the increased sodium excretion was not due primarily to inhibition of aldosterone secretion, but to some other natriuretic mechanism.