[Changes of endothelin in rats with normobaric hypoxia-induced pulmonary hypertension].

A model of pulmonary hypertension was established in rats by method of normobaric hypoxia to study the possible pathophysiological role of endothelin (ET) and other vasoactive substances in normobaric hypoxia-induced pulmonary hypertension. The ET levels of the lung and plasma, atrial natriuretic peptide (ANP) and angiotensin II level of plasma were measured by specific radioimmunoassay. The pulmonary arterial pressure (PAP) in hypoxic rats was significantly higher than that of the control. The ET level of plasma in hypoxic rats was significantly increased. The ET level of plasma was positively correlated with PAP in hypoxic rats. The ANP level of plasma was also increased, and the ET level of plasma was positively correlated with the ANP level of plasma in hypoxic rats.