Journal of Alcoholism & Drug Dependence
Open Access

Abstract

Association of Plasma Orexin A and Ethanol-Drinking Behaviors in Pregnant Rats

Kristen A Schmidt, Ada M-C Ho, Mark A Frye and Doo-Sup Choi

Aims: A sharp reduction in gestational alcohol preference has been observed in both humans and animals. This study investigated the specific neurobiological relationship between alcohol use, pregnancy and plasma orexin A. Methods: Adult female Wistar rats (n=15) were subjected to a two-bottle choice drinking paradigm (5% ethanol vs. tap water with measurement of liquid weight consumed and recorded daily) for 3 weeks prior to random assignment to mating group (n=8) vs. virgin group (n=7). Ethanol exposure was immediately resumed in the virgin group and following sperm plug observation in the mating group. Tail vein blood was collected during pre-ethanol exposure, pre-mating, and pregnancy days 12 and 19 for orexin A measurement by ELISA. Results: There was no significant difference in serum orexin A levels before or after alcohol exposure. A significant reduction (p<0.05) in alcohol preference was demonstrated in pregnant rats compared to virgin rats. In the pregnant group, there was a significant positive correlation between the percentage change in plasma orexin A level and alcohol preference (Pearson's r = 0.804, p<0.05) and consumption (Pearson's r = 0.800, p<0.05). Conclusions: These data suggest that pregnant rats have a significant reduction in alcohol preference compared to virgin rats exposed to alcohol for the same duration, substantiating a biological basis for diminished gestational alcohol intake. Plasma orexin A concentration during pregnancy may be associated with gestational alcohol intake. Short summary: Our results demonstrate that pregnant rats have a significant reduction in gestational alcohol preference compared to virgin rats, supporting a biological basis underlying gestational alcohol reduction. The observed significant positive correlation between gestational changes in alcohol consumption, preference and circulatory orexin A concentration suggests a relationship between orexin A and gestational alcohol intake.