Studies are being conducted in collaboration with my research group in Mexico City and the Center for Women’s Health Research in New York. We have observed the effects of under nutrition at various stages of pregnancy in the rat on sexual development, predisposition to diabetes and activity in the offspring.
We have shown that a maternal low-protein diet has gender specific effects on carbohydrate metabolism in the offspring progeny. For example, protein restriction during pregnancy but not lactation results in elevated resting blood sugars in male offspring after puberty. These male offspring also have disordered fat metabolism as evidenced by high triglyceride and cholesterol concentrations. Fasting insulins are also raised and these offspring have an abnormal response to glucose tolerance test. These males also have disordered expression of genes which regulate carbohydrate metabolism in the liver. We have undertaken studies on the concentration of leptin in the blood in offspring of undernourished mothers. Leptin is a hormone that is said to regulate appetitive levels. When leptin is low, appetite increases which clearly could lead to obesity. We demonstrated that female offspring have lower leptin levels following under nutrition either in pregnancy or in lactation.
We evaluated the effects of maternal protein restriction in pregnancy on the timing of the first estrus in female pups. First estrus was delayed by pups of mothers restricted during pregnancy and lactation and ovarian and uterine weights were reduced in these pups. These findings have great implications for the potential effects of maternal under nutrition on fertility. We are also studying effects of maternal nutrient restriction on the developing male fetus. Decreased nutrient availability to the fetus results in delayed testicular development and loss of fertility. |
