Effects of chronic ethanol exposure on cardiac receptor-adenylyl cyclase coupling: studies in cultured embryonic chick myocytes and ethanol fed rats.
Ethanol effects in the brain appear to be mediated at least in part by an alteration in receptor-effector coupling via guanine nucleotide-binding regulatory proteins (G proteins). To test the hypothesis that a similar pathway participates in the cardiotoxic effects of ethanol, we assessed the effects of chronic ethanol on two commonly used experimental models: embryonic chick myocytes in culture and ventricular myocardium from chronically fed rats. Ethanol had no effect on either the function or quantity of G proteins as assessed by effector-stimulated adenylyl cyclase activity and the levels of ADP-ribosylation substrates. In contrast, effector-stimulated adenylyl cyclase activity was significantly altered in the liver of ethanol-fed rats. These results suggest that receptor-effector coupling via G proteins in our two cardiac models is insensitive to ethanol and that ethanol effects may be species or organ specific.
Blumenthal
R S
RS
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Flinn
I W
IW
Proske
O
O
Jackson
D G
DG
Tena
R G
RG
Mitchell
M C
MC
Feldman
A M
AM
D020727:ADP-Ribosylation Factors; D000262:Adenylyl Cyclases / Q000187:drug effects* / Q000502:physiology*; D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D000431:Ethanol / Q000633:toxicity*; D019204:GTP-Binding Proteins / Q000187:drug effects* / Q000502:physiology*; D006321:Heart / Q000187:drug effects*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D000431:Ethanol; D019204:GTP-Binding Proteins; D020727:ADP-Ribosylation Factors; D000262:Adenylyl Cyclases