title: Effects of nitric oxide synthesis inhibition on mesenteric perfusion in young pigs.
abstract: We tested the hypothesis that nitric oxide (NO) modulates postprandial hyperemia in young pigs. To test this hypothesis, we studied five groups of 3-wk-old pigs: group 1: milk fed, N(G)-monomethyl-L-arginine (L-NMMA) and L-arginine (L-Arg) treated (n = 10); group 2: milk fed, placebo treated (n = 8); group 3: water fed, L-NMMA and L-Arg treated (n = 6); group 4: water fed, placebo treated (n = 4); and group 5: fasted sham fed, L-NMMA and L-Arg treated (n = 6). After catheter placement and electromagnetic flow probe instrumentation of the mesenteric artery, systemic blood pressure and mesenteric artery blood flow were measured during preprandial baseline, postprandial, and postprandial intra-arterial L-NMMA- and L-Arg-infused study periods. The same measurements were made in the milk- and water-fed placebo-treated groups except that diluent replaced the L-NMMA and L-Arg infusions. In the milk- and water-fed placebo-treated groups, a significant (analysis of variance, P < 0.05), postprandial hyperemia was observed. The change in blood flow was greater (P < 0.05) in the milk-fed group than in the water-fed group. Inhibition of NO synthesis with L-NMMA diminished (P < 0.05) the hyperemic responses to both water and milk feeding and resulted in a decrease (P < 0.05) in mesenteric artery perfusion in the fasted sham-fed state. We conclude that, in young pigs, NO is a modulator of mesenteric vascular tone in both the postprandial and fasted states.
authors.affiliation: Department of Pediatrics, Brown University School of Medicine, Women & Infants' Hospital of Rhode Island, Providence 02905, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Alemany
authors.forename: W
authors.initials: W
authors.lastname: Oh
authors.forename: B S
authors.initials: BS
authors.lastname: Stonestreet
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008892:Milk; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D019518:Postprandial Period; D012039:Regional Blood Flow / Q000187:drug effects; D013152:Splanchnic Circulation; D013552:Swine; D014867:Water; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D014867:Water; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase