抄録
The authors investigated effects of mercaptide-forming agents on the mechanical and electrical activity of the toad's isolated heart.
1. Cadmium chloride reduced and at last arrested completely the heartcontraction. Changes in the electrocardiogram were the prolongation of the PQ-interval, the shortening of the ST-interval, and the decrease of the amplitude of the R-wave and the T-wave. Sometimes a reversal of the T-wave was observed. At last, the P-wave disappeared. A prominent change of the myocard monophasic electrogram was a shortening of the duration.
2. Effects of mercuric derivatives, such as p-chloromercurobenzoic acid or phenylmercuric acetate were principally the same as the effect of cadmium chloride.
3. The ECG and monophasic myocard action potential survived the standstill of the heart with mercaptide-forming agents. This was seen with Cadmium chloride of 10-4 or 10-3 M.
4. The Changes in the mechanical and electrical activity of the heart with mercaptide-forming agents were corrected almost completely with cysteine hydrochloride or thioglycollic acid.
