[The role of energy substrates in regulation of the force-frequency relationship in the rat myocardium: effect of ambiocor].
The effect of ambiocor (15 mg/100 ml), which contains natural substrates of energy metabolism, on the contractility of papillary muscles (PM) of the right ventricle of the rat heart was studied at stimulation frequencies from 0.1 to 3.0 Hz at a temperature of 30 +/- 1 degrees C (n = 7). The effect was recorded 20 min after the addition of the preparation. It was demonstrated that ambiocor causes a significant (about 70%), independent of stimulation frequency, suppression of the amplitude of isometric contractions (negative inotropic effect), which is coupled with an increase in the relative value of the rest potentiation effect (a qualitative index of calcium content in sarcoplasmic reticulum). The influence of the mixture leads to significant alterations in the time parameters of the "contraction-relaxation" cycle: an increase in the duration of latent period; and a decrease in the time to peak tension and half-relaxation time (TR50%). The effect of the mixture is partially reversible. During the washing of the preparation with the control solution, the qualitative indicators of the contractile activity of papillary muscles are substantially improved in comparison with the initial ones. The character of alterations allows one to assume that the effect of ambiocor in the papillary muscles of the rat heart is realized partly through the suppression of the activity of sarcolemmal calcium channels.
O V
OV
Nakipova
A S
AS
Averin
N M
NM
Zakharova
M L
ML
Uchitel'
E V
EV
Grishina
L A
LA
Bogdanova
E I
EI
Maevskiĭ
D000818:Animals; D001224:Aspartic Acid / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D004338:Drug Combinations; D004734:Energy Metabolism; D005650:Fumarates / Q000494:pharmacology; D005971:Glutamates / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects*; D006706:Homeostasis; D008297:Male; D009126:Muscle Relaxation; D009200:Myocardial Contraction / Q000187:drug effects*; D009206:Myocardium / Q000378:metabolism*; D010210:Papillary Muscles / Q000187:drug effects / Q000502:physiology; D051381:Rats; D013386:Succinates / Q000494:pharmacology; D013644:Tartrates / Q000494:pharmacology; D013654:Taurine / Q000494:pharmacology
D004338:Drug Combinations; D005650:Fumarates; D005971:Glutamates; D013386:Succinates; D013644:Tartrates; D013654:Taurine; D001224:Aspartic Acid; D002118:Calcium; C029768:tartaric acid