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.
Department of Poultry Science, Texas Agricultural Experiment Station and Colleges of Medicine and Veterinary Medicine, Texas A&M University, College Station, Texas 77843, USA.
L A
LA
Martinez-Lemus
R K
RK
Hester
E J
EJ
Becker
J S
JS
Jeffrey
T W
TW
Odom
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