title: Direct effects of endothelin in the rat kidney.
abstract: In the present study, we tested the direct effects of endothelin (ET) on rat kidney in vivo. ET was infused into the left renal artery of anesthetized rats at a rate of 0.5, 5, 20, or 40 pmol/h. ET reduced ipsilateral urine volume (V), clearance of inulin (CIN), and clearance of p-aminohippuric acid (CPAH) in a dose-dependent manner. Thus ET at 20 pmol/h did not change V but decreased renal plasma flow (RPF) and glomerular filtration rate (GFR) by 27.6 +/- 14.3 and 30.8 +/- 10.4%, respectively, in the ipsilateral kidney. ET at 0.5 pmol/h was without effect and at 5 pmol/h had only minor effects on CIN and CPAH of ipsilateral kidney. At 40 pmol/h, ET reduced ipsilateral V, GFR, and RPF by 52.3 +/- 21.4, 58.4 +/- 14.5, and 72.5 +/- 10.6%, respectively. Filtration fraction and fractional excretion of Na remained unchanged during ET infusion. ET, 40 pmol/h, infused into the renal artery together with atrial natriuretic peptide (ANP) at a rate of 12 pmol/h reduced the ipsilateral V, GFR, and RPF by 33.2 +/- 6.3, 26.1 +/- 6.0, and 27.2 +/- 7.1%, respectively, decrements less than those with ET alone. When a calcium-channel blocker nicardipine was infused at a rate of 2.5 micrograms/h into the renal artery together with ET, 20 pmol/h, there was little change in the ipsilateral V, RPF, and GFR; ET, 40 pmol/h, with nicardipine did not change V and decreased GFR and RPF by 25.9 +/- 5.6 and 23.1 +/- 10.8%, respectively, decrements less than those without nicardipine.(ABSTRACT TRUNCATED AT 250 WORDS)
authors: Fourth Department of Internal Medicine, University of Tokyo, School of Medicine, Japan.
authors: T
authors: T
authors: Katoh
authors: H
authors: H
authors: Chang
authors: S
authors: S
authors: Uchida
authors: T
authors: T
authors: Okuda
authors: K
authors: K
authors: Kurokawa
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000494:pharmacology; D016232:Endothelins; D004730:Endothelium, Vascular; D005919:Glomerular Filtration Rate / Q000187:drug effects; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009529:Nicardipine / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D012079:Renal Circulation / Q000187:drug effects; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D016232:Endothelins; D010455:Peptides; D012965:Sodium Chloride; D009320:Atrial Natriuretic Factor; D012964:Sodium; D009529:Nicardipine