Effect of exogenous melatonin on ethanol-induced changes in Na(+),K(+)- and Ca(2+)-ATPase activities in rat synaptosomes.
In the present study, the effects of acute ethanol (EtOH) toxicity and of exogenous melatonin (MLT) on this toxicity were examined by measuring membrane-bound ATPases and acetylcholinesterase activities in rat synaptosomal membranes. The concentrations of plasma alpha-tocopherol and adrenal ascorbic acid (AA) were also measured. Synaptosomal Na(+),K(+)-ATPase and Ca(2+)-ATPase activities were significantly depressed in acute EtOH-intoxicated rats compared with controls, while acetylcholinesterase activity remained unaltered. Pretreatment with MLT (10 mg/kg) prior to acute EtOH administration prevented EtOH-induced inhibition of ATPases. Adrenal AA and plasma alpha-tocopherol levels were also depressed regardless of MLT pretreatment. MLT treatment alone affected neither membrane-bound enzyme activities nor tissue and blood levels of vitamins C and E. It is concluded that acute EtOH intoxication disturbs neural transport functions through the membrane-bound ATPase activity depression. Reduced AA and alpha-tocopherol levels may contribute to the neurodegenerative effects of EtOH. However, pretreatment with a high dose of MLT before EtOH administration may be beneficial to prevent EtOH-induced toxicity on ATPase-mediated neural transport functions.
Oner
P
P
Department of Biochemistry, Istanbul Faculty of Medicine, Istanbul University, Capa, 34390, Istanbul, Turkey. pernuron@hotmail.com
Cinar
F
F
Koçak
H
H
Gürdöl
F
F
D000818:Animals; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D000431:Ethanol / Q000494:pharmacology*; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013574:Synaptosomes / Q000187:drug effects* / Q000201:enzymology
D000431:Ethanol; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase; D008550:Melatonin