Role of prostaglandin in norepinephrine and renin release in canine kidney.

We investigated renin and norepinephrine (NE) release during electrical renal nerve stimulation (RNS) in relation to prostaglandin (PG) E2 concomitantly produced by the kidney in anesthetized dogs. During 10 min of continuous RNS (2.5-4 Hz), the increases in renin, NE, and PGE2 secretion rates were determined at 1 and 10 min after the start of stimulation. Under control conditions, almost the same extent of increase in the NE secretion rate was observed at 1 and 10 min of RNS, whereas the increase in renin secretion rate at 1 min of RNS was followed by a further increase at 10 min of RNS. On the other hand, an upward but not significant trend of increase in PGE2 secretion at 1 min of RNS was followed by a substantial level at 10 min of RNS. After administration of indomethacin, the increase in NE secretion rates at both 1 and 10 min of RNS were not altered, but the increase in renin secretion rate at 10 min of RNS was suppressed by approximately 50%, without any reduction of the increase in the renin secretion rate at 1 min of RNS. Consequently, the time-related change in the renin secretion rate during RNS was abolished. These results suggest that renin response to continuous RNS is enhanced by concomitantly generated PGs but not by NE, and furthermore, that endogenously generated PGs do not inhibit the release of NE from canine renal nerve endings.