Blood ethanol concentrations following intragastric intubation of neonatal rat pups

This study assessed the blood alcohol timecourse in neonatal male rats treated with ethanol via intubation of an ethanol-containing liquid diet (Sustacal, Mead Johnson). Experimental animals were maternally reared and received 1, 5, or 9 gavage feedings of a 20% (v/v) ethanol/nutriment solution, beginning at 0800 hours, on postnatal day 4 (PN4). Animals which received multiple intubations were treated twice daily, at 0800 and 1600 hours. The intubate was formulated to provide single doses of either 3.0 g/kg or 3.6 g/kg ethanol. Blood samples were obtained by toe clipping, and were collected at hourly intervals for up to 4 hours following the 0800 hour exposure on PN4, PN6, or PN8. Resultant blood alcohol concentrations were observed to be dose-dependent, and reduced by repeated ethanol exposure. Additionally, the time required to achieve apparent maximal blood levels was noted to be reduced by repetitive ethanol exposure, and to be inversely related to the magnitude of the ethanol dose. This study indicates that twice daily administration of substantial doses of ethanol in a dietary nutriment can be delivered to neonatal rats via intubation, and yield elevated, sustained blood alcohol levels (in a neonate evidencing unimpaired body growth), which are consistent with the limited data available concerning ethanol metabolism in the neonatal rat.