PHARMACOLOGICAL STUDIES OF INSECT METAMORPHOSING HORMONE: PONASTERONE A, ECDYSTERONE, AND INOKOSTERONE, IN THE RAT

摘要

References(16) Cited-By(1) The first insect moulting hormone called Ecdysone was isolated by Butenandt and Karlson (1) from the prothoracic gland of the pupa of silk worm. However, mainly due to minute supply of the compound the pharmacological study has not been made in the mammals. In 1966, Nakanishi, Takemotc et al. (2) found metamorphosing substances of the plant origin. They were closely related in chemical structure with Ecdysone. It is now possible to supply these hormones in large amounts obtained by the extractive or synthetic means. Since the demonstration by Karlson et al. (3) that the activation of certain genetic site of the insect chromosomes by Ecdysone derives from the increased synthesis of DNA-dependent RNA, the possible activation of the protein synthesis has stimulated the pharmacological studies of the hormones in the mammals. Otaka et al. (4, 5) have shown that the intraperitoneal injection of the metamorphosing plant hormone in mice activates an uptake of amino acids by the liver cells and therefore a biosynthesis of protein in the liver. However, Ecdysone itself is lacking in this effect (6). It is also reported that though long-term administration of the hormones does not affect markedly the body weight gain, some of the liver cells show a histological sign of increased metabolism (7). An activation of RNA synthesis by the metamorphosing hormones is also reported almost equipotent with that by 4-chlorotestosterone (5). By administering orally 200 to 800 μg/kg/day of Ponasterone A mixed in the diet to quail chicken. Kato et al. (8) have observed a dose-dependent activation of the molting change of feathers at the age of 17 to 20 days. In the present experiments attempts were made to observe the pharmacological effect of the metamorphosing steroids including Ponasterone A, Ecdysterone and Inokosterone in order to discuss the availability as therapeutic agent in mammals.