The Second Leukotriene Receptor in Human Lung

While the selective peptido-LT-antagonists ICI 198615 and MK 571 block the LT contractions in bronchial tissues they do not inhibit the vascular responses. These results suggest that more than one leukotriene receptor exists in man. One type is present on human airways (LT-1) and is inhibited by potent antagonists. A second type (LT-2) is present on the pulmonary veins and is resistant to these compounds. Unlike IC1198615 and MK571, LTE4 and BAY u9773 (LT-analog) antagonized LT-induced contractions on the human pulmonary veins. The clinical effect of antagonizing this second peptido-LT receptor type has yet to be assessed.