The effect of different nutritional states on puberty onset and the expression of hypothalamic Kiss1/kisspepetin

摘要

The possibility of an alteration in the age at which pubertal onset occurs has shown that we still lack knowledge on the molecular and physiological mechanisms of normal female puberty. In this study, the adjustment effects of different suckling and prepuberty nutrition on puberty onset and the expression of hypothalamic Kiss1/kisspeptin and gonadotrophin-releasing hormone (GnRH) were examined in 1-day-old female Sprague-Dawley rats. Animals were randomly assigned according to different suckling nutritional challenges (different milk intake before weaning) and prepuberty nutritional challenges (different food supply after weaning) into four groups: overnutrition group 1, overnutrition group 2 (O2), normal group (N, control group), and malnutrition group (M).In situ hybridization, Western blot analysis, and immunohistochemistry were used to analyze the expression of hypothalamic Kiss1/kisspeptin and GnRH. In the O1 group, GnRH and Kiss1/kisspeptin levels in the hypothalamus peaked at an early age, while malnutrition resulted in a delay in the GnRH and Kiss1/kisspeptin peaks. This study indicated that nutrition greatly affected the sexual development of female rats and that the effects of suckling nutrition were much greater than those of prepuberty nutrition.