The effects of chronic ethanol consumption and ethanol withdrawal on serum cholinesterase activity in rats.

Abstract

The effect of chronic ethanol consumption and ethanol withdrawal on serum cholinesterase (ChE) activity was investigated in female Wistar rats. Ethanol was administered by a modified liquid diet with 4.8% (v/v) ethanol for 3 days followed by 25 days on a liquid diet in which the ethanol concentration was increased to 7.2%. Control rats were pair-fed with an isocaloric liquid diet not containing ethanol. The blood ethanol concentration and serum ChE activity were measured at the end of the 4.8% ethanol consumption period; after 7, 14 and 35 days of ethanol (7.2%) consumption, and at 24 and 72 h after ethanol withdrawal following ethanol consumption of 35 days. Daily ethanol consumption of the rats ranged from 11.5 to 14.9 g/kg. Serum ChE activity was found significantly increased from the 3rd day of ethanol (4.8%) consumption. Serum ChE activities of the rats receiving 7.2% ethanol also increased significantly compared with rats ingesting 4.8% ethanol. Blood ethanol levels were measured as 121 and 0.88 mg/dl on the 35th day of ethanol (7.2%) consumption (just before ethanol withdrawal) and after 24 h of ethanol withdrawal, respectively. Increased serum ChE activity (1968 U/l) was still observed (1942 U/l) after 24 h of ethanol withdrawal. ChE activity returned to control levels (501 U/l) after 72 h of ethanol withdrawal. Audiogenic seizures indicating development of physical dependence on ethanol were also observed after 8 h of ethanol withdrawal in another individual group of ethanol-fed rats. Our results show that serum ChE activity is increased by chronic ethanol consumption in rats and that this increase is affected by ethanol concentration and duration of ethanol ingestion.