Morphometric studies of the renomedullary interstitial cells of Dahl hypertension-prone and hypertension-resistant rats.

Two strains of rats, one genetically sensitive (the Dahl S rat) and the other resistant (the Dahl R rat) to the hypertensive effect of a high-salt diet were studied morphometrically for determination of whether any anatomic differences were present in the renomedullary interstitial cells (RICs) that might help explain these strain differences. The rats resistant to the hypertensive effects of sodium chloride had more RIC than those from the sensitive strain. In addition, they were more heavily granulated. These findings may be related to the known antihypertensive function of the RICs and may help explain observed differences in the prostaglandin metabolism of the Dahl S and R rats.