title: Relationship between flow rate and NO production in postnatal mesenteric arteries.
abstract: We studied mesenteric arterial arcades from 3- and 35-day-old swine to determine the relationship between perfusate flow rate and release of nitric oxide (NO) into mesenteric effluent. Mesenteric arterial arcades were perfused under controlled-flow conditions with a peristaltic pump using warm oxygenated Krebs buffer. Basal rates of NO production were 43.6 +/- 4.2 vs. 12.1 +/- 2.5 nmol/min in 3- vs. 35-day-old mesentery during perfusion at in vivo flow rates (9 vs. 20 ml/min, respectively). Rate of NO production was directly related to flow rate over a wide range of flows (5-40 ml/min) in 3- but not 35-day-old mesentery. Both age groups demonstrated a brisk, albeit brief, increase in NO production in response to infusion of NO-dependent vasodilator substance P (10(-8) M/min). Tyrosine kinase inhibitor herbimycin A and L-arginine analog L-NMMA significantly attenuated flow-induced increase in NO production, and phosphatase inhibitor phenylarsine oxide increased magnitude of flow-induced increase in NO production in 3-day-olds. Removal of extracellular Ca(2+) and depletion of intracellular Ca(2+) stores (Ca(2+)-free Krebs with EGTA plus thapsigargin) had no effect on NO production in either group. Thus, basal rate of NO production is greater in mesenteric arterial arcades from 3- than from 35-day old swine, a direct relationship between flow rate and NO production rate is present in mesentery from 3- but not 35-day-olds, and phosphorylation events are necessary for this interaction to occur.
authors: Department of Pediatrics, The Ohio State University and The Vascular Biology Laboratory, Children's Research Institute, Children's Hospital, Columbus, Ohio 43205, USA. reberk@pediatrics.ohio-state.edu
authors: K M
authors: KM
authors: Reber
authors: G M
authors: GM
authors: Mager
authors: C E
authors: CE
authors: Miller
authors: P T
authors: PT
authors: Nowicki
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D016227:Benzoquinones; D001783:Blood Flow Velocity / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D047029:Lactams, Macrocyclic; D008638:Mesenteric Arteries / Q000254:growth & development* / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011809:Quinones / Q000494:pharmacology; D017828:Rifabutin / Q000031:analogs & derivatives; D013152:Splanchnic Circulation / Q000502:physiology*; D013552:Swine; D014664:Vasodilation / Q000502:physiology; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D016227:Benzoquinones; D004791:Enzyme Inhibitors; D047029:Lactams, Macrocyclic; D011809:Quinones; D017828:Rifabutin; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; C020754:herbimycin; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; D011505:Protein-Tyrosine Kinases; D010744:Phosphoric Monoester Hydrolases; D002118:Calcium