Ontogeny of ethanol elimination rates and ethanol-induced hypothermia were
examined as possible mechanisms contributing to the marked reduction in eth
anol sensitivity early in life (Little et al., 1996; Silveri & Spear, 1998)
and the notable gender difference in ethanol sleep-time seen in adult anim
als (Silveri & Spear, 1998). Elimination rates and brain/blood ethanol leve
ls were determined following doses of 1.5 or 4.5 g/kg ethanol in male and f
emale Sprague-Dawley rats at postnatal days (P)16, 26, 36, or 56. Animals w
ere sacrificed at 40, 80, or 160 min post-injection, with ethanol eliminati
on rates estimated from the slope of the regression of blood and brain alco
hol levels across the three sampling periods. P16 animals exhibited the slo
west rate of ethanol metabolism, while no gender effects were evident at an
y age. Observed ontogenetic increases in ethanol hypothermia were not syste
matically related to the ontogeny of ethanol metabolism. Factors other than
ontogenetic changes in ethanol metabolism, hypothermia, or the distributio
n of ethanol between brain and blood must underlie the relative insensitivi
ty to ethanol often reported in young and adolescent organisms, a fruitful
area for future studies given the frequent use and misuse of alcohol by hum
an adolescents. (C) 2000 Elsevier Science Inc. All rights reserved.