胎生期の藥理學的研究

Abstract

By the combined administration of dihydrostreptomycin and KI or single administrations of these two substances into the developing hen's eggs, the author investigated the influences of SM and KI on the development of chick embryo, the excretions of SM and KI into its allantoic fluid and the distribution of I in the cardinal organs, and conducted the histological examinations on the liver of the chick embryo. Conclusions were drawn as follows : 1) The development of chick embryo was roughly similar to that of the controls except that it was slightly inhibited in the case received the injection of 40 mg of SM. No malformation was observed, and though several deaths were found during the incubation, perfect hatching was attained in all the cases. 2) The excretion of SM into the allantoic fluid was found extremely poor. The highest rate of the excretion was 1.51% recorded in the case received the injection of 40 mg of SM on the 18th day of incubation, and the lowest rate was 0.03% recorded in the case of 20 mg of SM on the 9th day. In either of the above cases, the excretion attained to the highest value on the 18th day of incubation. 3) The excretion of I into the allantonic fluid was better compared with that of SM, but it was pretty inhibited on the 9th and 12th day of incubation, showing the highest value of 24.00% recorded in the case of 5 mg of KI combined with SM on the 15th day. In other cases it attained to high values on the 18th day of incubation. 4) As to the distribution of I in the cardinal organs of chick embryo, it was noted that the contents of I in the brain, heart and liver were found respectively increased comparing with that of controls, and the weight of each of above organs was also found increased. The content of I in the case with 5 mg of KI further increased compared with that in the case with 2.5 mg of KI in either case of single administration or of combined administration with SM. 5) In the histological examinations on the liver of chick embryo, no noteworthy finding was recognized in the early part of the incubation period, but in the latter part of the incubation period, lipoid degeneration, slight regional necrobiosis or necrosis in the hepatic cells and slight round cells infiltration in Glisson's capsules were found in all the cases. Besides these, vacuolar degeneration was also recognized in the case injected with KI alone or KI combined with SM.