実験的心筋硬塞におけるAspartate Transaminase-isozymeの変動に関する研究

抄録

Previously N.KATUNUMA et al. discovered that GOT from pig liver consist of two types of isozyme, the one being localized in cell supernatant fraction (GOTs) and the other in mitochondria (GOTM). Subsequently they succeeded in purifying the isozyme to almost single protein. Using the technique of column chromatographic separation, the author could elucidate the mechanism of the leakage of the GOT-isozvme from the heart muscles into serum in the case of experimental myocardial infarction. Method s In dogs, experimental myocardial infarction was produced by ligation of the circumflex branch of the left coronarv arterv, and a few to several dogs were killed at a certain period of time after the occlusion (24 hr, 2 day, 3 day, 4 day, 5 day, 7 day, 10 day, 14 day after operation) and the direct ECG was recorded respectively, before slaughter. Then, the removed heart was separated into the infarcted and non-infarcted portions, and the GOT ac-tivity in the heart muscles obtained from each portion was measured. In order to separate the GOT-isozyrne quantitatively, HUZlNO-KATUNUMA'S method was used, and the GOT activity was expressed by a modified method of FRIEDMANN-HAUGEN. Results 1. GOT-isozyme in heart muscles. 1) The ratio of the total activity of GOTS to that of GOTM in normal heart muscles was about 4 to 1 on the average of 2 dogs. 2) At 24 hours after the occlusion, the ratio of the total activitv of GOTS to that of GOTM in the non-infarcted portion was about 4 to 1 on the average of 5 dogs, while in the infarcted portion, it was about 1.2 to 1. Namely, the total activity of GOTS in the infarcted portion was decreased to about 2S per cent of that in the non-infarcted portion. On the contrary, any significant change of the total activitv of GOT_M in the infarcted portion could not be observed compared with that of the non-infarcted portion. 3) At 2 days, 3 clays and 4 clays after the occlusion in 2 dogs respectively, no change of the total activity of GOT_M could be observed between the infarcted portion and non-infarctecl portlon, just like at 24 hours after the occlusion. As for the total activity of GOTs, the rates of decrease were 71.8 and 72.1 per cent after 2 days, 74.8 and 77.7 per cent after 3 days, 73.9 and 77.5 per cent after 4 days respectively in the infarcted portion compared with that in the non-infarcted portion.