Effect of cyclooxygenase inhibition on renal blood flow autoregulation in SHR.
The effect of acute and chronic indomethacin treatment on renal blood flow (RBF) autoregulation was studied in 10- and 40-wk-old spontaneously hypertensive rats (SHR). RBF autoregulation was substantially reduced in 40-wk-old SHR both during acute and chronic indomethacin treatment, whereas no effect was seen in the young SHR. The pressure range of autoregulation was 169 +/- 9 to 130 +/- 5 mmHg in the untreated 40-wk-old SHR, and 154 +/- 14 to 146 +/- 6 mmHg in indomethacin-treated 40-wk-old SHR (P less than 0.001). Indomethacin treatment had no effect on control RBF, mean arterial pressure, or renal vascular resistance in the 40-wk-old SHR. After removal of the renal nerves, RBF autoregulation during indomethacin treatment was restored in 40-wk-old SHR. The pressure range of RBF autoregulation was 158 +/- 7 to 142 +/- 7 mmHg in sham-operated animals, significantly different from the denervated 40-wk-old SHR, where RBF was autoregulated from 150 +/- 5 to 118 +/- 6 mmHg (P less than 0.01) during indomethacin treatment. The afferent arteriolar diameter (DAA) was studied by the microsphere method in 10-wk-old SHR and in untreated and indomethacin-treated 40-wk-old SHR. DAA was significantly greater in 40-wk-old compared with 10-wk-old SHR (22.1 +/- 0.4 vs. 17.9 +/- 0.5 microns) (P less than 0.01), whereas indomethacin treatment in 40-wk-old SHR did not influence the DAA significantly (21.5 +/- 0.3 microns, P greater than 0.10).(ABSTRACT TRUNCATED AT 250 WORDS)
Iversen
B M
BM
Medical Department A, University of Bergen, Norway.
Kvam
F I
FI
Mørkrid
L
L
Sekse
I
I
Ofstad
J
J
D000818:Animals; D001160:Arterioles / Q000033:anatomy & histology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D003714:Denervation; D006439:Hemodynamics; D006706:Homeostasis / Q000187:drug effects*; D007213:Indomethacin / Q000494:pharmacology; D007668:Kidney / Q000294:innervation; D008297:Male; D010477:Perfusion; D011312:Pressure; D011453:Prostaglandins / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012079:Renal Circulation / Q000187:drug effects*
D016861:Cyclooxygenase Inhibitors; D011453:Prostaglandins; D007213:Indomethacin