Long-term voluntary ethanol consumption induces impairment of the mechanical performance in the papillary muscle of Sardinian alcohol-preferring rats.
The effects of chronic (26 weeks) ethanol consumption on cardiac muscle contractility in Sardinian alcohol-preferring drinkers (sP-D) and Sardinian alcohol-preferring naive (sP-N) rats were investigated. Experiments were carried out 1 week after ethanol administration ceased. Length-tension and force-frequency responses in left ventricular papillary muscles from both sP-D and sP-N rats were recorded in vitro. Papillary muscles were gradually stretched in steps of 5% of the reference (initial) length (L(r)) from 100 to 130% L(r). In sP-D rats, length-tension relationships showed a significant reduction in active tension: at optimal length for maximum active tension (130% L(r)), the developed force value (1.38 +/- 0.36 mN/mg, dry tissue) was 54% lower than that found in sP-N rats (3.16 +/- 0.6 mN/mg, dry tissue). In sP-D papillary muscles, a decrease in contractile behaviour was also observed in force-frequency responses (0.03-120 pulse/min), when compared with sP-N rats; developed force was found to be reduced by about 2.5 times. These results indicate that long-term ethanol consumption impairs the mechanical performance of sP papillary muscle, inducing a negative inotropic effect.
Licheri
D
D
Department of Applied Sciences for Biosystems, Division of Human Physiology and Nutrition, University of Cagliari, Via Porcell 4, I-09124 Cagliari, Italy.
Vargiu
R
R
Fadda
F
F
Fabrizi
A
A
Mancinelli
R
R
D000428:Alcohol Drinking / Q000235:genetics; D000818:Animals; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D003864:Depression, Chemical; D004558:Electric Stimulation; D000431:Ethanol / Q000494:pharmacology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects* / Q000502:physiology; D010210:Papillary Muscles / Q000187:drug effects* / Q000502:physiology; D051381:Rats
D002492:Central Nervous System Depressants; D000431:Ethanol