Effects of interleukin-1 beta on the renin-angiotensin-aldosterone system in rats

A bolus IP injection of interleukin-1 beta (IL-1 beta) (8 micrograms.kg-1) increased blood pressure and PRA without affecting plasma aldosterone (ALDO) concentration. IL-1 beta strongly attenuated angiotensin-II (ANG-II, 10(-8) M)-stimulated ALDO secretion by both isolated zona glomerulosa (ZG) cells and capsular strips. These findings suggest that IL-1 beta exerts a twofold opposite action on the main components of the rat renin-angiotensin-aldosterone system: simultaneous stimulation of renin release by kidneys and inhibition of the stimulatory effect of ANG-II on ALDO production. At the highest concentrations (10(-6)/10(-5) M), IL-1 beta was found to lower also basal ALDO output by isolated ZG cells, but not by capsular strips. However, in the presence of saralasin 10(-8) M (a competitive inhibitor of ANG-II) and captopril 10(-8) M (an angiotensin-I-converting enzyme inhibitor), IL-1 beta significantly reduced basal ALDO yield of capsular strips. These last results would suggest that IL-1 beta could also similarly affect the intra-adrenal renin-angiotensin system, which seems to be involved in the local regulation of ZG secretory activity.