異常発生環境による畸形の成立

ハツカネズミによる表現型模写の研究 (第一報)

抄録

Seizo Katsunuma (1948) described that some congenital abnormalities such as pseudencephaly, spina bifida, anophthalmia, harelip, heart abnormalities etc. were occasionally found in rodents embryos whose mother animals had been injected intravenously with some vital staining dyes, namely lithioncarmin, trypanred or trypanblue etc. He presumed that such congenital abnormalities might be caused either by the abnormal permeability of the placenta with vitally stained syncytium cells or by the toxic effects of these staining agents.
Having succeeded his experiments the author studied the critical period of these abnormalities and various conditions for their manifestation.
Methods: Female mice on the 9th-11th day of pregnancy were injected with 2.5-4.0% lithioncarmin solution intravenously once every day for 3 or 4 days.
Results: 306 embryos of the 14-16th foetal days were obtained from 42 mother animals by vivisection. Among these embryos abnormalities as follows were found, 2 pseudencephalies, 3 slight oxycephalies (one of them with r-cerebrum hypoplasia), 2 with back blisters … myelencephalic blebs? … (one of them furthermore with blood-blister on the back of the left fore feet) (and these above mentioned embryos were all alived), 1 spina bifida, 1 severe oxycephaly, 3 microcephalies (these died on the 12-13th foetal days), 32 small chorions and 7 placentas without embryos (partial sterility).
Among 266 control individuals obtained from 37 normal mother animals no marked abnormality was seen except some small chorions.
The author presumes therefore the critical period of manifestation of these abnormalities to be in the 9th-11th foetal days, namely in the period in which from one to several primitive segments are formed. It is not yet decided whether the appearance of these abnormalities should be ascribed to the abnormal permeability of the vitally stained placenta or to the toxic effects of the vital staining dyes. The experiments will be continued.