Digitalis-屬藥物の心筋細胞, 特に該核酸に及ぼす影響に就て

Abstract

It seems necessary to investigate the pattern of nucleic acids in the living tissues for the study on the mechanism of stimulant action on heart, of cumulative action and of intoxication. with digitalis glycosides. In this experiment digitalis glycosides (digitoxin, helleborein, g-strophanthin and digicorin) were independently applied to the chick embryo, frog and cat, studying the change of nucleic acids contents of heart muscle cells by the hematoxyline, Feulgen's or methylgreen-pyronine staining, from which the following results were obtained : (1) Digitalis glycosides stimulated, and later inhibited the growth of chick embryonal heart muscle culture in vitro. Desoxyribonucleic acic (D.N.A.) was increased when the growth was stimulated and decreased with the inhibition of growth. (2) Besides the affliction of heart muscle no toxic effect was observed on frog by the consecutive administration of digitalis glycosides, however, the changes of nuclei of ventricle cells were fairly remarkable. Digitoxin and g-strophanthin increased the number of nucleus of ventricle and decreased the red-nucleus count of the heart muscle cells by methylgreen-pyronine staining, at the same time high molecular D.N.Ag.was increased and low molecular D.N.A. was decreased. On the other hand, helleborein increased the number of nucleus of auriclei and ventricle tissue cells to some extent, and slightly increased the high as well as the low molecular D.N.A.. No effect of digicorin was observed on the heart other than the decrease of low molecular D.N.A. contents. (3) The consecutive administration of digitalis glycosides always drove the cat into a toxic state, e. g. vomiting, and histological changes were observed on cytoplasm and nuclei either of the heart muscle or of the papillary muscles. The effects of digitoxin and g-strophanthin on these muscles were clearly seen, while that of digicorin was very slight In these cases D.N.A. contents were, increased, but in few cases decreased. Ribonucleic acid (R.N.A.) was increased when g-strophanthin or helleborein was applied. Thus it was concluded that digitalis glycosides had some effect on the nucleic acid pattern of the heart muscle, that is, the change of D.N.A. contents Were followed by the stimulant and toxic action of glycosides, suggesting that the enzyme concerned with nucleic acid metabolism were playing an important role on these phenomena.