Effects of verapamil and BAY K 8644 on the hypoxic contraction of the isolated human pulmonary artery.
To examine the effect of hypoxia on the human pulmonary artery (HPA), HPA segments (2 mm, o.d.) were suspended and changes in isometric force with hypoxia (PO2 = 44 +/- 3 mmHg, mean +/- S.E.) were measured. HPA contracted with hypoxia and the tension developed with 15 min of hypoxia was 127 +/- 36 (mean +/- S.E.) mg. Verapamil at 47 +/- 10% 10(-6) M inhibited and 10(-6) M BAY K 8644 enhanced the hypoxic response by (p less than 0.01) and 396 +/- 106% (p less than 0.05), respectively, compared with preceding values. These results show that activation of voltage-dependent Ca2+ channels also plays an important role in the mechanism of hypoxic pulmonary vasoconstriction in man.
Ohe
M
M
First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
Ogata
M
M
Shirato
K
K
Takishima
T
T
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D010101:Oxygen Consumption; D011651:Pulmonary Artery / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D014700:Verapamil / Q000494:pharmacology*
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D014700:Verapamil