MAD (Methylandrostenediol) 並にParotin (唾液腺ホルモン) の鶏胎仔窒素代謝に及ぼす影響に就て

抄録

Through the investigation of the influence of parotin and MAD on the nitrogen metabolism of the chick embryo, the author attempted to elucidate the influence of these hormons on the nitrogen metabolism during the embryonal stage. The followings are the principal results of the investigation.
1) The promotion or inhibition in the development of chick embryo exercised by the addition of parotin were found mild in either of the cases, but, generally speaking, the development inclined to the inhibition side in the cases with parotin of higher concentration.
2) In the cases with the administration of MAD, the development of chick embryo was found slightly inclined to the promotion side in the initial stage of the incubation with low concentration solution. However, in the terminal stage, the development demonstrated an tendency toward rather inhibition.
3) No development promoting action was demonstrated by the administration of parotin combined with MAD.
4) In the cases of the administration of parotin or MAD, no remarkable changes in the quantity of the allantoic fluid were generally noted, and no definite tendency in this respect was observed.
5) When parotin combined with MAD was administered, the quantity of the allantoic fluid demonstrated an tendency toward decrease, though slightly.
6) The inhibitive action of the parotin on the excretion of nitrogen was found weak, but stronger inhibition was noted when the administration was made on the 5th day of incubation compared with the result obtained in the cases with the administration prior to the incubation.
7) The decrease in the excretion of nitrogen into the allantoic fluid caused by the administration of MAD was recognized more evident compared with that in the cases with parotin, though the degree was generally mild.
8) The influence caused by the administration of MAD began to appear on the 12th or the 15th day of incubation, and it disappeared on the 18th day of incubation.
9) When MAD was administered on the 5th day of incubation, the influence appeared slightly earlier compared with the cases in which the administration was made prior to the incubation, and a mild decrease in the excretion of nitrogen was recognized on the 9th day of incubation.
10) The decrease in the excretion of nitrogen into the allantoic fluid was not evidently noted in the cases with the administration of parotin combined with MAD.
In short, the development promoting action on the chick embryo by parotin or MAD was extremely weak, and even inhibiting action seemed to have been noted with the administration of these substances at higher concentrations. No definite tendency in the influence of these substances on the quantity of the allantoic fluid could be noted, although a mild tendency of decrease was recognized when these substances were administered in combination. The inhibitive action of parotin or MAD on the excretion of nitrogen, though extremely weak, was recognized even in the animals in the embryonal stage, showing a slightly stronger action in the cases with MAD. However, the decrease in the excretion of nitrogen due to the administration of parotin combined with MAD was not evident.