Alcohol’s pharmacokinetics in the lactating rat.

M.Y. PEPINO; P. ABATE; O.B. HAYMAL; MOLINA J.C.

Baltimore, Washington

Congreso; 2006 Scientific Meeting of the Research Society on Alcoholism.; 2006

Research Society on Alcoholism

Experimental studies have shown that administration of the same dose of alcohol results in significantly lower blood alcohol levels (BAL) in lactating when compare to non-lactating rats. A plausible explanation to these BAL varations is the extensive modification of the gastroinstestinal system that occurs during lactation in order to cope with the high nutritional demands associated with milk production, in addition to these modifications, the act of suckling itself may increase hormones that affect gastric motility and emptying rates. Therefore, we hypothesized that the stimulation of the mammary glands when pups breastfeed plays a role in the modification of  alcohol pharmacokinetic in lactating rats. To verify this hypothesis, 14 rats on lactation day 16-17 were tested. A catheter was implanted into the jugular vein 24 hours before blood sampling. After surgery, dams were deprived from food and pups were removed from the maternal cage for 24 hours. Thirty minutes before a 2.5 g/kg i.g. alcohol administration, half of the dams were reunited with their respective litter and pups were allowed to to suckle for that time period (Suckling Group). The remaining dams were isolated from the pups (No Suckling Group). BAL were measured at 5, 15, 30, 45, 60, 75, 90, 105 and 240 min using headspace gas chromatography analysis. The BAL data under both conditions (Suckling/No Suckling) were then used to estimate classical pharmacokinetics measures (peak BAL, Time to peak, dissapearance rate and area under the curve- AUC). Preliminary analysis revealed that alcohol peaked (194 ± 19 mg%) at 55.7 ± 14.5 minutes in the dams in the Suckling Group and reached a peak of 209 ± 20 mg% at 51.4 ± 7.6 min in the No Suckling Group (both P’s > 0.10). Alcohol dissapearance rate (Suckling Group= -0.49 ± 0.07, No Suckling Group = -0.47 ± 0.006) and AUC were not different between the two groups (all P’s > 0.70). Taken togehter, the data revealed that a single episode of breastfeeding does not affect alcohol pharmacokinetcs in the lactating rat.