Natriuretic activity in plasma and urine of salt-loaded @entity1 and XXXX .

@entity1 @entity742 @entity101 @entity1372 @entity35 @entity1368 @entity2010
The present study was designed to examine the question of whether or not there is a natriuretic hormonal substance involved in the renal regulation of @entity1372 balance. For this purpose, procedures for concentration and fractionation of plasma and urine samples and a sensitive bioassay for demonstrating changes in renal @entity1372 excretion were developed. The natriuretic assay utilized @entity35 with mild @entity2010 which were maintained in salt and water balance. Using these approaches a natriuretic humoral substance was demonstrated in plasma and urine from normal @entity1 and @entity742 , and in @entity1 with @entity1368 or essential @entity101 . It seems likely that this substance participates in day to day regulation of @entity1372 balance because it was not detectable in @entity1372 -depleted subjects and it consistently appeared in the @entity1372 -loaded subjects. The hormonal agent may not act immediately and its activity can be apparent for up to 3 hr. Full expression of its activity requires that the assay animals be appropriately volume expanded. This suggests that the increases in @entity1372 excretion mediated by this hormonal substance depend in part on the coparticipation of other physical and perhaps humoral factors. This natriuretic substance appears to be of large molecular weight or carried by a large molecule. The data suggest that it acts, at least in part, to block @entity1372 reabsorption in a more distal portion of the tubule.
