EFFECTS OF INDOMETHACIN ON RENOMEDULLARY INTERSTITIAL-CELLS

  • 1 January 1976
    • journal article
    • research article
    • Vol. 34  (5) , 522-528
Abstract
The effects of indomethacin, an inhibitor of prostaglandin synthesis, on rat renomedullary interstitial cells were studied. Indomethacin, 5 mg/kg i.v. in divided doses over 48 h, resulted in reduced granularity of interstitial cells (5.56 .+-. 1.37 vs. 9.85 .+-. 1.07 granules per cell, (P < 0.001) and, at the same time, inhibited the incorporation of 14C-arachidonate into renomedullary phospholipids (715 + 11 vs. 1299 + 42 cpm/.mu.g of lipid orthophosphate; P < 0.001). 14C-arachidonate incorporation into cortical phospholipids was not affected by indomethacin. There was a close correlation between individual granule counts and 14C-arachidonate incorporation into medullary phospholipids for both control (r = 0.85) and indomethacin-treated animals (r = 0.9). Radioactivity in the cytosol fraction was depressed by indomethacin reflecting inhibition of prostaglandin synthesis; cytosol radioactivity correlated closely with individual granule count (r = 0.81) in the indomethacin-treated but not in the control rats. Indomethacin given as a single dose 4 h prior to sacrifice resulted in a significant depression of 14C-arachidonate incorporation but did not affect granularity of interstitial cells. Granularity of renomedullary interstitial cells may reflect the activity of prostaglandin synthesis and the rate of prostaglandin precursor delivery from microsomal phospholipids.