Interleukin-1 regulation of collecting duct prostaglandin E2 and cyclic nucleotide accumulation.

Interleukin-1 (IL-1) causes a diuresis and natriuresis in experimental animals. The natriuresis is due, at least in part, to IL-1 stimulation of prostaglandin E2 (PGE2) synthesis by the inner medullary collecting duct (IMCD), with resultant inhibition of Na(+)-K(+)-adenosine triphosphatase activity. It is unknown whether IL-1 affects other signal transduction systems in the IMCDs that regulate nephron sodium and water reabsorption. Furthermore, indirect evidence suggests that IL-1 inhibits sodium and water transport in other nephron segments. Consequently we examined (1) the effect of IL-1 on cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) accumulation by rat IMCD cells and (2) IL-1 stimulation of signal transduction mechanisms throughout the nephron. IL-1 had no affect on cGMP or arginine vasopressin-dependent (AVP-dependent) or isoproterenol-dependent cAMP accumulation in cultured rat IMCD cells. IL-1 increased PGE2 levels in rabbit IMCD, cortical collecting tubule (CCT), and to a lesser extent, medullary thick ascending limb cells, but had no effect on proximal tubule cells. IL-1 also did not alter AVP-dependent cAMP accumulation in the CCT. The failure of IL-1 to reduce AVP responsiveness in the CCT was not due to culture conditions, because AVP-dependent cAMP accumulation in freshly isolated CCT cells was also not affected by the cytokine but was inhibited by exogenous PGE2.(ABSTRACT TRUNCATED AT 250 WORDS)