Reduction of cerebral NaCl concentration can abolish mineralocorticoid escape.

Abstract

The effect of lowering cerebrospinal fluid (CSF) Na concentration on renal Na excretion (UNaV) was investigated in conscious sheep undergoing mineralocorticoid escape induced by intravenous infusion of aldosterone (20 micrograms.ml-1.h-1) for 3 days. On the 3rd day of aldosterone administration, when plasma and CSF Na concentration and mean arterial blood pressure (MABP) were increased as a result of the mineralocorticoid treatment, a reduction in the CSF Na concentration was induced by infusing a Na-free solution of 300 mmol/l mannitol (1 ml/h) into a lateral cerebral ventricle. This caused significant reductions in UNaV and MABP and a significant increase in renal free water clearance (CH2..