Effects of obesity induced by litter size reduction on the sexual development of male rats and potential impacts on sperm quality

• Grant number: 19/14657-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2019
• End date: November 30, 2020
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Samara Urban de Oliva
• Grantee: Rafaela Doretto do Valle Freitas
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

The overweight and obesity pandemic occurs in all countries, independent of financial conditions (particularly in urban areas), in both sexes and in all age groups. Obesity can lead to changes of the sexual hormones, spermatogenesis and sperm maturation, leading to reduced sperm quality, oligozoospermia, damage to DNA integrity, affecting motility and sperm capacitation, and thus interfering with the fertilization process and the embryo quality. In addition, increased adipose tissue may lead to increase of sexual steroids levels, adipokines and leptin, as well as the aromatization of androgens in estrogens; this may accelerate the onset of puberty and, subsequently, the seminal quality and homeostasis of sexual hormones in adult phase. However, the literature is contradictory about the effects of obesity on sperm and male fertility due several limitations inherent in human studies. Male obesity experimental models were established and can be used to assess the impact of male obesity on sperm function. Thus, the objective of this study is to evaluate the effects of induced obesity in the neonatal period, by litter size reduction, on the establishment of puberty and its possible impact on sperm parameters at the puberty and adult phases.