EFFECTS OF LEVAMISOLE ON ETHANOL-INDUCED SUPPRESSION OF LACTATIONAL IMMUNE TRANSFER IN RATS

Maternal ethanol consumption in rats has been shown to inhibit lactati onal transfer of immunity to Trichinella spiralis (T. spiralis) from d ams to their neonates. The purpose of this study was to determine if t his depressed immune transfer could be altered by treating the dams wi th a known immunostimulatory drug during pregnancy and lactation. Grou ps of female rats were fed ethanol-containing or were pair-fed isocalo ric control liquid diets for 30 days, infected orally with 1,000 T. sp iralis larva, and then continued on diet for 10 days to allow the adul t worms to establish. The animals were placed on chow diets (maximum 5 days) and mated 1 to 1 with males. On day 1 of pregnancy the animals were returned to their respective liquid diets through pregnancy and l actation. One-half of the ethanol-treated animals was given 15 mg/kg b ody weight of levamisole in the diet beginning on day 10 of pregnancy and continuing until day 17 of lactation. On day 19 of lactation, pups from all experimental groups were challenged orally with 200 T. spira lis larva, and killed at 3 or 8 days postchallenge. Assays for intesti nal worm burdens, IgG anti-T. spiralis serum antibodies, and mesenteri c lymph node cell proliferation were conducted. At both sacrifice peri ods, pups from ethanol-treated animals showed significantly higher int estinal worm counts (decreased immunity) and significantly lower titer s of specific antibodies than the pups of pair-fed animals or pups of animals receiving levamisole in addition to ethanol. There were no dif ferences between pups of the ethanol/levamisole dams and pair-fed dams in worm counts or antibody titers. No differences in mesenteric lymph node cell proliferation in response to T. spiralis antigen or to conc anavalin A was observed between the three groups. These results indica te that administration of levamisole to ethanol-induced, immunosuppres sed dams can reverse some of the deleterious effects normally seen in lactational immune transfer to suckling pups.