The effects of indomethacin (IND) and PGI2 on the tone of human isolated pulmonary arteries were studied. Baseline tone of the vessels was increased by IND, electric stimulation (ES), norepinephrine (NE), prostaglandin F2α (PDF2α) or K+-excess. This high tone was decreased by PGI2 in a concentration dependent manner. IC50 values (molar concentrations producing 50% relaxation) for PGI2 were in the same concentration range (10 to 58.8 nmoles/l). The potency of the relaxant effect of PGI2 was inversely related to the magnitude of tone induced prior to the addition of PGI2 and independent of the type of tone inducer. It is suggested that the relaxant effect of prostacyclin on human pulmonary artery may be of clinical importance in the treatment of conditions associated with a rise in pulmonary vascular resistance.
- Pulmonary artery
- Pulmonary vasodilatation
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine