Whereas prostaglandin I2 (PGI2), a major metabolite of human lymphatics, does not itself affect lymphatic contractility significantly, it is able to counterbalance the contractile response to thromboxane and leukotrienes. We now demonstrate that leukotrienes C4 and D4 evoke a dose-dependent increased production of PGI2 from human lymphatics. It is likely that leukotrienes either exert a contractile rhythmic effect on human lymphatics or, alternatively, evoke increased PGI2-formation which relaxes human lymphatics. These mechanisms may be of local importance in regulating lymphatic "tone" at sites of inflammation as leukotrienes are liberated from activated white blood cells.
Adolescent Adult