[Effects of KB-1043 and some non-steroidal anti-inflammatory drugs on prostaglandin and SRS-A synthesis].

The effects of KB-1043, a new non-steroidal anti-inflammatory agent, on prostaglandin (PG) and SRS-A synthesis were investigated and compared with those of reference drugs. KB-1043 (3 X 10(-5) approximately 3 X 10(-4)M) inhibited the PG synthesis induced by PG synthetase prepared from bovine seminal vesicles. The IC50 value was 1.33 X 10(-4)M. The activity of KB-1043 was less than that of indomethacin, but was about 8 times stronger than that of aspirin. However, KB-1043 (10(-6) and 10(-5)M) did not increase the SRS-A released from sensitized guinea pig lung. With a concentration of 10(-4), KB-1043 decreased the SRS-A release. On the other hand, indomethacin (10(-6) and 10(-5)M), mefenamic acid (10(-6) and 10(-5)M), phenylbutazone (10(-5) and 10(-4)M) and aspirin (10(-4) and 10(-3)M) distinctly increased the SRS-A release from sensitized guinea pig lung.