著者
Hiroshi MIKASHIMA Shuzo TAKEHARA Yoshito MURAMOTO Takako KHOMARU Michio TERASAWA Tetsuya TAHARA Yutaka MARUYAMA
出版者
The Japanese Pharmacological Society
雑誌
The Japanese Journal of Pharmacology (ISSN:00215198)
巻号頁・発行日
vol.44, no.4, pp.387-391, 1987 (Released:2006-09-15)
参考文献数
13
被引用文献数
10 9

The antagonistic effect of etizolam, an anti-anxiety drug, on platelet-activating factor (PAF) was investigated in rabbit platelets in vitro. Etizolam inhibited PAF-induced aggregation in a dose-dependent manner, with an IC50 of 3.8 μM, about one tenth that of triazolam (IC50=30 μM). At 300 μM, it inhibited both ADP and arachidonic acid-induced aggregation only slightly, while the other anti-anxiety drugs tested had no effect on PAF-induced aggregation even at this concentration. Etizolam and triazolam inhibited the specific binding of 3H-PAF to PAF receptor sites on washed rabbit platelets with IC50 values of 22 nM and 320 nM, respectively. Diazepam and estazolam were inactive even at 1 μM. These results indicate that etizolam is a specific antagonist of PAF.