Pulmonary artery endothelium-dependent vasodilation is impaired in a chicken model of pulmonary hypertension.
Among chicken strains, broilers are prone to pulmonary hypertension, whereas Leghorns are not. Relaxations to endothelium-dependent (ACh, A23187) and endothelium-independent [sodium nitroprusside (SNP), papaverine (PPV)] vasodilators were compared in preconstricted pulmonary artery (PA) rings from these chicken strains. ACh (10(-7), 10(-6), and 10(-5) M)- and A23187 (10(-6) and 10(-5.5) M)-induced relaxations were smaller (P < 0.05) in broilers than Leghorns. N(G)-nitro-L-arginine methyl ester (10(-3.5) M) caused similar reductions in ACh-induced relaxations in both strains. L-Arginine (10(-4) M) enhanced ACh-induced relaxations more in broilers than Leghorns. Relaxations to 10(-10)-10(-6) M SNP did not differ between strains, but were greater (P < 0.05) in broilers than Leghorns at higher concentrations (10(-5) and 10(-4) M). PPV (10(-4) M)- and SNP (10(-4) M)-induced maximal relaxations were greater in broilers than in Leghorns (176.2 +/- 14.7 vs. 120.9 +/- 14.7% and 201.3 +/- 7.8 vs. 171.2 +/- 10.7%, respectively, P < 0.05). Broiler PA rings appear to have increased intrinsic tone and reduced endothelium-derived nitric oxide activity, both of which may contribute to the susceptibility of broiler chickens to pulmonary hypertension.
Martinez-Lemus
L A
LA
Department of Poultry Science, Texas Agricultural Experiment Station and Colleges of Medicine and Veterinary Medicine, Texas A&M University, College Station, Texas 77843, USA.
Hester
R K
RK
Becker
E J
EJ
Jeffrey
J S
JS
Odom
T W
TW
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002645:Chickens / Q000145:classification / Q000502:physiology*; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006976:Hypertension, Pulmonary / Q000503:physiopathology*; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010208:Papaverine / Q000494:pharmacology; D011651:Pulmonary Artery / Q000187:drug effects / Q000503:physiopathology*; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology
D004791:Enzyme Inhibitors; D007476:Ionophores; D014665:Vasodilator Agents; D009599:Nitroprusside; D000001:Calcimycin; D001120:Arginine; D010208:Papaverine; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester