1. This study was done to examine the possibility that escape from the sodium retention produced by aldosterone may be associated with an inhibition of prolactin secretion. Plasma prolactin concentrations were determined in seven patients with adrenal adenoma and aldosteronism, before and after unilateral adrenalectomy, at a time when they were in balance on a sodium intake of 109 mmol/day.
2. After operation, plasma aldosterone was normal [before operation, 52·7 ± 12·1 (supine), 64·6 ± 9·1 ng/dl (upright); after operation, 6·8 ± 1·5 (supine), 11·1 ± 3·0 ng/dl (upright)], while plasma prolactin remained unchanged [before operation, 19·6 ± 2·8 (supine), 15·5 ± 3·3 ng/ml (upright); after operation, 23·8 ± 2·3 (supine), 11·1 ± 3·0 ng/ml (upright)].
3. Our results do not support a role for prolactin in the renal response to aldosterone in man.
