Effect of beta-methyldigoxin on the embryonal and fetal chicken heart
Rickenbacher, J.; Schläpfer, R.
Schweizerische Medizinische Wochenschrift 115(18): 625-629
1985
ISSN/ISBN: 0036-7672 PMID: 4001908 Document Number: 244467
The effect of .beta.-methyldigoxin continuously diffused into the circulatory system of the heart of 4-9 day-old chicken embryos was studied. In the early embryonic type of contraction, there was a rise in the diastolic minimum pressure phase and finally rhythmic disturbances with a serum concentration of 25 .times. 10-3 ng/ml. There was finally an arrest of the contracted heart. In the early fetal type of contraction, a positive inotropic effect was observed at first. Thereafter, at a serum concentration of < 20 .times. 10-3 ng/ml, intoxication symptoms occurred with a rise in diastolic and a drop in systolic pressure, as well as anomalies in frequency and rhythm. The heart of the chicken embryo showed increasing sensitivity .beta.-methyldigoxin from the 7th brooding day on. From the standpoint of formal development, this would correspond to an age of 7 wk in humans.