Abstract
Slice tissues of rat lung were preincubated with vitamin A (VA) or vitamin A acid (VAA) and then incubated with endotoxin. After the reaction, the amount of LTC4, LTB4 and 6-KPGF1α in the reactive solution were analysed quantitatively by RIA following the method of Salali or Powell et al. TLC4 was significantly suppressed by 10-6M VA. And 10-8M VA still showed this suppression. The induction of LTB4 was also suppressed significantly by 10-7M VA. VAA suppressed the induction of LTC4 significantly at the concentration from 10-7M to 10-9M. And 10-8M VAA showed the most significant suppression. The induction of LTB4 was also suppressed significantly by 10-9M VAA but was accelated by 10-7M. However VAA did not interfere the synthesis of 6-KPGF1α. The values of LTB4 and LTC4 determined by RIA were confirmed by the combined method of HPLC and RIA. These suggest that VA and VAA will suppress the synthesis of lipoxygenase products specifically in vitro experiment as well as in vivo experiment already shown in the former report.
