Maternal malnutrition alters the leptin expression in the rats epididymis
F. Gombar, F. Sampaio & C. Ramos
Several papers show that maternal malnutrition can affect the reproductive capability of the offspring. Leptin is an important regulator of the reproductive system, however little is known about its role in the epididymis. The goal of this study was to evaluate whether the maternal malnutrition during lactation can alter the expression of leptin and its receptors in the epididymis of rats. Six rat dams were randomly assigned to the control group (C), with free access to a standard laboratory diet containing 23% protein; and to a protein-energy-restricted group (PER), with free access to an isoenergy and protein-restricted diet containing 8% protein. After weaning, four male pups of each group had free access to the standard laboratory diet until 90 days of age, when they were killed. The gene expression of leptin and leptin receptors, ObRa and ObRb, were evaluated by qPCR, while the protein expression was evaluated by immunohistochemistry in the caput, corpus and cauda of epididymis. Values were expressed as mean±S.E.M. Data were analysed using Students t-test and the level of significance was set as P<0.05. Maternal malnutrition increased the gene expression in the caput (ObRa-C=0.5±0.1, PER=2.1±0.6, P<0.04; ObRb-C=0.2±0.1, PER=0.8±0.2, P<0.02; leptin C=0.7±0.3, PER=2.2±0.3, P<0.04) decreased in the cauda (ObRa-C=1.4±0.1, PER=0.8±0.1, P<0.04; ObRb-C=0.02±0.003, PER=0.006±0.005, P<0.007; leptin C=1.2±0.2, PER=0.4±0.1, P<0.02) while there was no statistical difference in the corpus of epididymis. Imunohistochemistry show positive stain for leptin and leptin receptor in all epididymis regions. The epididymis role in the maturation of spermatozoa is well established. The fact that maternal malnutrition during lactation altered leptin and its receptors expression in a region specific way raise the possibility that this hormone could have an important role in the molecular mechanisms that govern the epididymis function that are still poorly defined.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This work was supported, however funding details unavailable.