Cerebrospinal fluid sodium concentration and salt appetite

Abstract

Infusion into a lateral brain ventricle (IVT) of different hypertonic (0.7 M) saccharide solutions decreased [Na+] of cerebrospinal fluid (CSF). Increased Na appetite of moderately Na-deplete sheep was observed during infusion of mannitol, l-glucose or l-fucose, while no change was observed during infusion of d-glucose, d-fucose, d-mannose, 2-deoxy-d-glucose, 3-O-methyl-glucose or fructose. In other experiments, increased Na appetite was observed during infusion of 2.3 mM phlorizin (a relatively specific blocker of Na-coupled glucose transport into cells) or 2.3 mM phlorizin plus 0.7 M d-glucose. In addition, phlorizin eliminated the characteristic decrease in Na appetite but did not affect ..