Pre-weaning over and under-feeding alters onset of puberty in the rat without affecting kisspeptin

The perinatal nutritional environment can permanentlyinfluence body weight, potentially leading to changes in pubertyonset and reproductive function. We hypothesized that perinatalunder- or overfeeding would alter puberty onset and influenceconcentrations of a neuropeptide crucial for successful puberty,kisspeptin. We manipulated Wistar rat litter sizes to derive small(SL), control (CL), and large (LL) litters containing 4, 12, and 20rat pups respectively. This manipulation results in an overweightphenotype in SL rats and a lean phenotype in LL that persiststhroughout life. To investigate whether successful puberty onsetis affected by neonatal under- or overfeeding, we examinedindices of growth and development, including the onset ofpuberty, as well as the central expression of Kiss1 mRNA in thesepups. Male LL rats reached puberty later than those from CL.These males also had reduced plasma testosterone and elevated17beta-estradiol concentrations at puberty