RESIDENT RESEARCH AWARD - PULMONARY HYPOXIA INCREASES ENDOTHELIN-1 GENE-EXPRESSION IN SHEEP

The hypoxic pulmonary vasoconstrictor response (HPVR) is a physiologic mechanism for directing pulmonary blood flow to nonhypoxic regions of the lung. The mechanism of this response remains unclear. To investigate the role of endothelin-1 (ET-1), a potent vasoconstrictor produced by vascular endothelium, in HPVR an in vivo model of alveolar hypoxia was developed. When one lung in an anesthetized sheep was made hypoxic, the static ET-1 mRNA levels in lung tissue increased in proportion to the observed decrease in pulmonary blood flow (Q(p)) to that lung. With reversal of hypoxia, Q(p) and ET-1 levels returned to baseline. This relationship between alveolar hypoxia and ET-1 mRNA levels suggests a role for ET-1 in the local pulmonary response to hypoxia. (C) 1994 Academic Press, Inc.