Carbon Monoxide inhibits hypoxic pulmonary vasoconstriction in rats by a cGMP-independent mechanism

Abstract

Hypoxia activates erythropoietin-producing cells, chemoreceptor cells of the carotid body and pul- monary artery smooth muscle cells (PSMC) with a com-

Key words Hypoxia · Pulmonary artery · Carbon monoxide&bdy:

parable arterial PO2 threshold of some 70 mmHg. The

inhibition by CO of the hypoxic responses in the two for- mer cell types has led to the proposal that a haemopro- tein is involved in the detection of the PO2 levels. Here, we report the effect of CO on the hypoxic pulmonary va- soconstriction (HPV). Pulmonary arterial pressure (PAP) was measured in an in situ, blood-perfused lung prepara- tion. PAP in normoxia (20% O2, 5% CO2) .