Zona glomerulosa cell responses to atrial natriuretic factor in genetically hypertensive rats

We examined whether abnormalities in target cell responsiveness to atrial natriuretic factor (ANF), similar to those previously found in the kidney, could also be present in the zona glomerulosa cells of spontaneously hypertensive rats (SHR) and salt-sensitive Dahl rats (S rats). We found an attenuated aldosterone (Aldo) response to angiotensin II (ANG II) in zona glomerulosa cell suspensions isolated from hypertensive SHR compared with those from Wistar-Kyoto (WKY) rats, whereas cells derived from hypertensive S rats showed a significantly higher Aldo response to the maximum stimulatory dose of ANG II than those from salt-resistant Dahl rats (R rats). The maximum observed Aldo responses to ACTH stimulation were not different in SHR or S rats compared with their respective controls. ANF exerted a potent inhibitory action on both ANG II- and ACTH-stimulated secretions of glomerulosa cell suspensions, without any difference in its potency between hypertensive and control rats. The equipotent inhibitory action of ANF on the ANG II- and ACTH-stimulated secretion of Aldo in those cell suspensions suggests that the previously observed alterations in the target cell responsiveness to ANF do not exist in the adrenal zona glomerulosa cells of SHR and Dahl S rats.