On the brain involvement in saline loading natriuresis--an indirect evidence for the cerebral participation in the functional expression of the atrial natriuretic system.

The ablation of the anterior third cerebral ventricle region totally prevented the homeostatically effective natriuresis which should have followed hypertonic saline loading in conscious sheep. The increased cerebrospinal fluid (CSF) sodium concentration potentiated, and the decreased CSF[Na] prevented, natriuresis during isotonic saline loading. It is thus probable that a cerebral natriuretic system is involved in the functional expression of any other peripheral natriuretic system, e.g. the heart atrial natriuretic system which has been found to play a role in both hypertonic and isotonic saline loading natriuresis.