Locally produced EDRF controls preglomerular resistance and ultrafiltration coefficient.
During systemic acute blockade of endogenous endothelial-derived relaxing factor (EDRF) with N-monomethyl-L-arginine (NMA), a significant rise in arterial blood pressure (BP) occurred in the anesthetized rat. Renal vasoconstriction was also seen, with complex changes in glomerular hemodynamics; both preglomerular (RA) and efferent arteriolar (RE) resistances increased, producing a fall in glomerular plasma flow (QA) and a rise in glomerular blood pressure (PGC). The glomerular capillary ultrafiltration coefficient (Kf) was reduced. The net effect was a small fall in single-nephron glomerular filtration rate (SNGFR). To determine the effects of local EDRF blockade, two additional groups were studied with intrarenal administration of NMA; in the first series, one-tenth of the systemic dose was given, which produced no change in BP, a small renal vasoconstriction with an increase in RA, but no change in RE; thus PGC was unaffected. Kf fell, and a small reduction in SNGFR was seen. With a larger intrarenal dose of NMA (one-fifth systemic) a moderate rise in BP occurred, but only RA rose; RE and PGC were unaffected, and Kf and SNGFR fell. These observations suggest that locally produced EDRF controls RA and Kf and that a rise in RE and PGC is only seen with systemic EDRF blockade when a large rise in BP occurs.
Deng
A
A
Department of Physiology, West Virginia University, Morgantown 26506.
Baylis
C
C
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006439:Hemodynamics / Q000187:drug effects; D007678:Kidney Glomerulus / Q000098:blood supply*; D008297:Male; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012079:Renal Circulation / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology*; D019323:omega-N-Methylarginine
D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine