FOOD RESTRICTION, GONADOTROPINS, AND BEHAVIOR IN THE LACTATING RAT

This study sought to quantify effects of undernutrition on behaviors a nd to relate these to gonadotropin and prolactin concentrations in the lactating dam. Dams were studied in a 2 X 3 factorial design with lit ter size and food intake as the two factors. Behavioral data were coll ected from each dam and her litter on day 9, day 14, and day 19 of lac tation, and maternal blood samples collected. Plasma was analyzed for luteinizing hormone, follicle stimulating hormone and prolactin. On da y 15 of lactation, percent time nursing, number of pups actively nursi ng, total number of pups nursing and dam location acted as mediating f actors of the effect of diet group on plasma luteinizing hormone conce ntration. No such relationships were seen for plasma follicle stimulat ing hormone, and only nest condition score appeared to be a mediator f or plasma prolactin concentration. In conclusion, this analysis sugges ts that food restriction indirectly influences plasma concentration of luteinizing hormone, but not follicle stimulating hormone, by changin g maternal and pup behaviors. The relationship among diet, behavior an d circulating prolactin was less clear.