Most potent vasoconstrictor of the pulmonary aery is:: (A) Endothelin, (B) Hypoxia, (C) Angiotensin, (D) TXA2
Answer is B. Endothelin, urotensin, angiotensin are the potent constrictors of the systemic vessels. In case of the pulmonary vessels, hypoxia is the strongest vasoconstrictor, acting the O2-sensitive K+ channels in the pulmonary vascular smooth muscle cells (VSMCs).