title: Chronic alcohol ingestion alters the calcium permeability of sarcoplasmic reticulum of rat skeletal muscle.
abstract: Heavy sarcoplasmic reticulum (SR) was prepared from skeletal muscle of control and chronic alcoholic rats, and the effect of in vitro addition of ethanol on the passive Ca2+ permeability was studied. The SR was loaded with Ca2+ in the absence of ATP. Then efflux was initiated by adding an EGTA solution to decrease the extravesicular Ca2+ concentration. The decrease of Ca2+ content of the SR was measured by an optical method using an encapsulated metallochromic indicator (calcein). The Ca2+ permeability of alcoholic rat SR was higher than that of control rats, especially at low external Ca2+ concentrations (below 1 microM). An in vitro (acute) exposure of SR to ethanol increased the Ca2+ permeability of the SR. However, the degree of increase in alcoholic rat SR was smaller than that in control rat SR.
mesh_terms: D000437:Alcoholism / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002463:Cell Membrane Permeability / Q000187:drug effects*; D004396:Coloring Agents; D005452:Fluoresceins; D006801:Humans; D066298:In Vitro Techniques; D007202:Indicators and Reagents; D009114:Murexide / Q000031:analogs & derivatives; D009132:Muscles / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012519:Sarcoplasmic Reticulum / Q000187:drug effects*; D013050:Spectrometry, Fluorescence
chemical_list: D004396:Coloring Agents; D005452:Fluoresceins; D007202:Indicators and Reagents; C026042:tetramethylmurexide; D009114:Murexide; D002118:Calcium; C007740:fluorexon