title: Effects of pyridoxalated hemoglobin polyoxyethylene conjugate and stroma-free hemoglobin on renal vascular responsiveness to vasoactive substances in isolated perfused rat kidney.
abstract: The effects of pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) and stroma-free hemoglobin (SFH) on vascular responsiveness to various vasoactive substances were examined in isolated perfused rat kidneys. The kidneys isolated from rats were perfused with 6% PHP, 6% SFH, and 6% hydroxyethylstarch (HES) solution at a constant flow rate. Vascular responsiveness to acetylcholine (ACh), nitroglycerin (NG), norepinephrine (NE), and angiotensin-II (ANG-II) was examined by measuring the perfusion pressure (PP). Effects of inhibition of endothelium-derived relaxing factor (EDRF) by NG-monomethyl L-arginine (L-NMMA) on NE-induced and ANG-II-induced renal vascular responses were examined. ACh and NG induced a dose-dependent decrease in perfusion pressure (PP) in all groups. NE and ANG-II induced an increase in PP in all groups, but NE-induced and ANG-II-induced responses in the PHP-perfused and SFH-perfused groups were significantly larger than those in the HES-perfused group. L-NMMA did not alter vascular responsiveness to NE and ANG-II. These results indicate that PHP and SFH do not inhibit EDRF induced by ACh, but hemoglobin moiety per se does augment the vascular responsiveness to NE and ANG-II in the isolated perfused rat kidney.
authors.affiliation: Department of Pharmacology, Kumamoto University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nishi
authors.forename: S
authors.initials: S
authors.lastname: Ueda
authors.forename: D
authors.initials: D
authors.lastname: Sato
authors.forename: K
authors.initials: K
authors.lastname: Nishi
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001802:Blood Substitutes / Q000494:pharmacology; D006454:Hemoglobins / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000494:pharmacology; D005996:Nitroglycerin / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D010477:Perfusion; D011092:Polyethylene Glycols / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012079:Renal Circulation / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000494:pharmacology*; D019323:omega-N-Methylarginine
chemical_list: D001802:Blood Substitutes; D006454:Hemoglobins; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; C016484:hemoglobin, stroma free; C050907:pyridoxalated-hemoglobin-polyethylene glycol conjugate; D000804:Angiotensin II; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D011092:Polyethylene Glycols; D001120:Arginine; D005996:Nitroglycerin; D000109:Acetylcholine; D009638:Norepinephrine