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Biomedical subjects

C Y Chiou

Publications and source records attributed to C Y Chiou.

At least 55 records · Page 3Linked to original sources
PubMed1976

Effects of calcium antagonist, 6-(N, N-diethylamino) hexyl-3, 4, 5-trimethoxybenzoate, on digitalis-induced arrhythmias and cardiac contractions.

6-(N, N-Diethylamino) hexyl-3, 4, 5-trimethylbenzoate (TMB-6) and lidocaine were equipotent (1 mg/kg) in the conversion of ectopic rhythms to normal rhythms in digoxin-toxic dogs. However, TMB-6 had fewer side effects on heart rates and dp/dt than lidocaine. TMB-6 inhibited the contractile force of electrically stimulated dog and guinea-pig atria and ventricles at concentrations ranging from 2.5 X 10(-5) to 1.7 X 10(-4) M. Elevation of extracellular Ca++ concentrations from 2.7 to 5.4 mM produced a significant increase in the ID50 of TMB-6 in atria (from 2.5 X 10(-5) to 5.0 X 10(-5) M in dogs and from 7.2 X 10(-5) to 1.0 X 10(-4) M in guinea pigs). TMB-6 (7.3 X 10(-5) to 2.4 X 10(-4) M) depressed the amplitude of Ca++-dependent action potentials in depolarized dog cardiac Purkinje fibers. These results are discussed with regard to the antagonism of TMB-6 on Ca++ availability in the myocardium which leads to the conversion of cardiac arrhythmias.

Action Potentials↗
PubMed1975

Studies on the mechanism of action of a new Ca-2+ antagonist, 8-(N,N-diethylamino)octyl 3,4,5-trimethoxybenzoate hydrochloride in smooth and skeletal muscles.

1. The rabbit aortic strip, guinea-pig ileum and rabbit skeletal muscle sarcoplasmic reticulum preparations were used to determine at which sites and in what manner 8-(N,N-diethylamino)-octyl 3,4,5,-trimethoxybenzoate (TMB-8) interferes with Ca2+ availability in smooth and skeletal muscles. 2. TMB-8 (50 muM) significantly inhibited equivalent responses of the rabbit aortic strip to KCl and noradrenaline. 3. TMB-8 (65 muM) produced no significant alteration in the extracellular space of the guinea-pig ileum as measured with [3H]-sorbitol. 4. The resting cellular Ca2+ influx as well as the resting 45Ca2+ efflux in the guinea-pig ileum preparation were significantly inhibited by TMB-8 (65 muM). 5. TMB-8 (5 muM and 50 muM) had no significant effect on the uptake of 45Ca2+ by the sarcoplasmic reticulum preparation of skeletal muscle; however, TMB-8 (5 muM) did significantly inhibit the caffeine (20 mM)-induced release of 45Ca2+ from this preparation. 6. It is concluded that TMB-8 reduces Ca2+ availability in smooth and skeletal muscles by stabilizing Ca2+ binding to cellular Ca2+ stores and thereby inhibits the release of this Ca2+ by contractile stimuli.

Animals↗