Sadek I A
Exp Parasitol. 1983 Oct;56(2):241-6. doi: 10.1016/0014-4894(83)90068-1.
20-Methylcholanthrene induced the encystment of Opalina ranarum when injected into its host, Rana ridibunda. Also, urine of frogs injected with this hydrocarbon induced encystment of the parasites. It is speculated that methylcholanthrene or its metabolites reach the parasites in the recta of the frogs and stimulate the parasites to encyst. Injections of frogs with methylcholanthrene and 13-cis-retinoic acid failed to induce cyst formation in the opalinids. Moreover, encystment of the parasite was lessened when the host was injected with methylcholanthrene and retinyl palmitate. Urine of frogs injected with methylcholanthrene and 13-cis-retinoic acid failed to induce cyst formation in the parasites. Moreover, urine of frogs injected with this hydrocarbon and retinyl palmitate lessened the induction of cyst formation in the parasites in vitro. It is suggested that 13-cis-retinoic acid as well as retinyl palmitate inhibits methylcholanthrene-induced cyst formation of the opalinids.
将20-甲基胆蒽注入其宿主泽蛙体内时，可诱导蛙片虫形成包囊。此外，注射了这种碳氢化合物的青蛙尿液也能诱导寄生虫形成包囊。据推测，甲基胆蒽或其代谢产物在青蛙直肠中到达寄生虫，并刺激寄生虫形成包囊。给青蛙注射甲基胆蒽和13-顺式视黄酸未能诱导蛙片虫形成包囊。此外，当宿主注射甲基胆蒽和棕榈酸视黄酯时，寄生虫的包囊形成减少。注射甲基胆蒽和13-顺式视黄酸的青蛙尿液未能诱导寄生虫形成包囊。此外，注射这种碳氢化合物和棕榈酸视黄酯的青蛙尿液在体外减少了寄生虫包囊形成的诱导。提示13-顺式视黄酸以及棕榈酸视黄酯可抑制甲基胆蒽诱导的蛙片虫包囊形成。
