Studies on the inhibitory effect of indomethacin and meclofenamate on the adrenalectomy-induced increase in plasma renin concentration.

Bilateral adrenalectomy combined with a sodium-deficient diet caused a time-dependent increase in plasma renin concentration in rats. Seventy-two hours after adrenalectomy the inhibitors of prostaglandin biosynthesis indomethacin and meclofenamate diminished the plasma renin concentration by about 50%. This effect was independent of the amount of renin released. Indomethacin and meclofenamate fully retained their ability to reduce the plasma renin concentration when the renal sympathetic nerves or the macular densa cells of the kidneys no longer contributed to renin release. It is concluded that in adrenalectomized rats renal prostaglandins effect the baro-receptor-mechanism in the afferent arterioles and thus enhance renin release.