Initial sensitivity and acute tolerance to ethanol in the P and NP lines of rats

• Published in: Pharmacology, biochemistry and behavior Vol. 19; no. 4; pp. 683 - 686
• Main Authors: Waller, M.B., McBride, W.J., Lumeng, L., Li, T.-K.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.10.1983; Elsevier Science
• Subjects: Acute tolerance to ethanol; Alcohol-nonpreferring rats; Alcohol-preferring rats; Alcoholism and acute alcohol poisoning; Animals; Biological and medical sciences; Brain - metabolism; Drug Tolerance; Ethanol - metabolism; Ethanol - pharmacology; Half-Life; Initial sensitivity to ethanol; Male; Medical sciences; Postural Balance - drug effects; Rats; Rats, Inbred Strains; Species Specificity; Toxicology; Acute tolerance to ethanol; Alcohol-preferring rats; Alcohol-nonpreferring rats; Initial sensitivity to ethanol; Tolerance; Vertebrata; Mammalia; Ethanol; Rat; Rodentia
• ISSN: 0091-3057; 1873-5177
• DOI: 10.1016/0091-3057(83)90345-3

We recently reported that selectively bred, alcohol-preferring (P) and alcohol-nonpreferring (NP) rats differ in sensitivity to a single sedative-hypnotic dose of ethanol, as measured by performance in the jump test. The present study examines the contributions of initial sensitivity and acute tolerance development to this difference. Initial sensitivity, assessed by brain alcohol content upon loss of the aerial righting reflex, was not significantly different between P and NP groups given 3 g ethanol/kg body weight intraperitoneally. Acute tolerance was indexed from blood alcohol concentrations (BAC) upon recovery of jumping performance following two successive ethanol doses. Practiced P and NP rats were required to jump 35 cm to a descending platform following the IP injection of 2.0 g ethanol/kg. The NP group took signiificantly longer (74 min) than the P (33 min) group whereupon BAC 1 of NP rats (234 mg%) was significantly lower than that of P rats (250 mg%). A second injection (1.0 g/kg) was given immediately after the animals reached the 35 cm criterion. Again, NP rats took significantly longer (124 min) than P rats (52 min) to jump 35 cm and BAC 2 of NP animals was lower (295 mg%) than that of P rats (343 mg%). The difference between BAC 2 and BAC 1, the measure of tolerance development, was significantly larger for P rats (90 mg%) than for NP rats (61 mg%). No significant differences in blood ethanol elimination weree observed between the groups. The data indicate no difference in initial sensitivity between P and NP animals but that P rats develop acute tolerance more rapidly and/or to a greater degree than do NP rats. The results are consistent with a relationship in these selectively bred lines of rats between alcohol preference and the development of acute tolerance.