Accumulation of granules in the juxtaglomerular cells occurred in rats which were maintained for 5 to 6 weeks on a diet low in sodium, chloride. Cytological evidence suggests that this was probably a storage phase of secretion following a decrease in the rate of liberation of the granules. Administration of DCA (desoxycorticosterone acetate) to salt-deficient rats did not alter this appearance of the juxtaglomerular cells.
Two per cent sodium chloride taken in the drinking water consumed for 4 weeks by similar animals caused degranulation of the juxtaglomerular cells. This effect was enhanced by DCA. DCA administered to animals on a normal salt intake produced a lesser degree of degranulation. Cytological changes in degranulated cells suggested that these represent a stage of hyperactivity in the secretory cycle produced by an increase in the rate of liberation of granules.
A hypothesis is suggested that the juxtaglomerular cells are involved in the hormonal regulation of sodium metabolism and/or blood pressure.