Differential effects of acute ethanol treatment on cardiac contractile function in young adult and senescent mice.
It is understood that marked biochemical, molecular, and performance alterations occur in cardiovascular tissues related to aging. It is logical, therefore, that differences in the cardiovascular response to ethanol consumption, when comparing younger with older individuals, may exist. We compared the left ventricular function of 6- and 15-month-old (senescent) mice and 16-month-old (senescent) inducible nitric oxide synthase knockout mice (n=7 each) before and subsequent to acute treatment with 60% ethanol (2 g/kg, i.p.). A Millar 1.4 Fr conductance/micromanometer catheter was placed into the left ventricle of the mice for acquisition of pressure-volume loops. Heart contractile functions were significantly decreased in the senescent group, compared with findings in the younger mice. Subsequent to ethanol treatment, the younger mice showed a significant reduction in cardiac function, with a 28% decrease in cardiac index, a 29% decrease in end-systolic elastance, and a 16% decrease in preload recruitable stroke work (P<.01). Conversely, the senescent mice showed significantly increased contractile function, with a 40% increase in end-systolic elastance (P<.01) and a 19% increase in preload recruitable stroke work (P<.05). The myocardial cyclic guanosine monophosphate levels were significantly higher in the older group (P<.002), and subsequent to ethanol treatment, they were decreased by 68.5% (P<.001). Northern blot analysis demonstrated inducible nitric oxide synthase message only in senescent myocardial tissues. Moreover, the cardiac function of senescent inducible nitric oxide synthase knockout mice was comparable with that of young mice, and after ethanol treatment, cardiac function decreased significantly, just as that for young mice did, with a 26% decrease in cardiac index (P<.05) and a 23% decrease in preload recruitable stroke work (P<.01). It was concluded that the differential cardiovascular function and response to acute ethanol
Shi
J
J
Arizona Prevention Center, College of Medicine, The University of Arizona, Tucson, AZ 85724, USA.
Larson
D F
DF
Yang
B
B
Hunter
K
K
Gorman
M
M
Montes
S
S
Beischel
J
J
Watson
R R
RR
D000375:Aging / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D002492:Central Nervous System Depressants / Q000097:blood / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D000431:Ethanol / Q000097:blood / Q000494:pharmacology*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009200:Myocardial Contraction / Q000187:drug effects* / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D016277:Ventricular Function, Left / Q000187:drug effects*
D002492:Central Nervous System Depressants; D000431:Ethanol; D000242:Cyclic AMP; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D006152:Cyclic GMP