title: EGTA-extractable calmodulin in platelet membrane is lower in alcoholics than in controls.
abstract: The purpose of this study was to determine calmodulin distribution in platelets of alcoholics. Eight alcoholics were diagnosed by DSM-III (Diagnostic and Statistical Manual of Mental Disorders, 3rd edition) criteria prior to admission to the Alcohol Unit, VA Hospital, San Antonio, TX. Whole blood was drawn after a five day washout period, and again after 30 days of disulfiram treatment. Platelets were prepared from the whole blood, suspended in Ringer's-citrate-dextrose buffer (RCD), divided into 2 aliquots, then sonicated and centrifuged (100K X g). Supernatants were assayed for calmodulin content by RIA. The pellets were resuspended by sonication in 1 mM EGTA in RCD or 1% (w/v) Lubrol-PX in RCD, then centrifuged at 100K X g. Calmodulin was measured in the EGTA and Lubrol supernatants. EGTA-extractable calmodulin in pre-disulfiram, post-disulfiram, and control subjects was 5.07 +/- 2.2 (SD), 5.19 +/- 1.7 (SD), and 10.5 +/- 6.7 (SD) ng calmodulin/mg whole platelet protein. The EGTA-extractable calmodulin was significantly lower in alcoholics pre- or post-disulfiram than in controls (p less than 0.025). These preliminary results suggest an alteration in platelet membranes of alcoholics that affects the binding of calmodulin.
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000097:blood*; D001792:Blood Platelets / Q000032:analysis*; D002147:Calmodulin / Q000302:isolation & purification*; D002462:Cell Membrane / Q000032:analysis; D004533:Egtazic Acid; D005026:Ethylene Glycols; D006801:Humans; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay
chemical_list: D002147:Calmodulin; D005026:Ethylene Glycols; D004533:Egtazic Acid