Expressão gênica de GHR, IGF1 E IGF2 no ovário de ratas submetidas ao treinamento resistido e/ou ao GH

Abstract

Growth hormone (GH) is used indiscriminately by female athletes and those attending gyms and the effect of exogenous GH administration associated with resistance exercise on the ovaries of these women is unknown. GH can act directly on target organs through its receptor (GHR) or indirectly by increasing the insulin-like growth factor 1 (IGF1) produced by the liver and released into the bloodstream, or by local production of IGF1 and IGF2. The objective of this study was to verify the gene expression of Igf1, Igf2, and Ghr and the follicular and corpus luteum (CL) population in the ovaries of Wistar rats submitted to resistance exercise associated with recombinant human GH (rhGH). The 40 rats were divided into 4 groups (n = 10): control (CT); rats administered 0.2 IU/Kg rhGH (GH); rats submitted to resistance exercise (RT); and rats submitted to rhGH administration and resistance exercise (RTGH). The resistance exercise was performed in the aquatic environment with a load of 50% of the animal’s weight, in 4 sets of 10 jumps, with an interval of one minute between sets. The rats underwent exercise and rhGH 3 times/week, on intercalary days, for 30 days. After the experimental period, the rats were euthanized in the diestrus phase, the ovaries were collected for morphology and for gene expression (RT-qPCR) of the Ghr, Igf1 and Igf2 genes. The statistical analysis performed used ANOVA followed by the Tukey test (P <0.05). No differences were found between the groups in Igf1 and Igf2 gene expression, or in the number of primordial, primary, secundary, tertiary follicles and corpora lutea. The mRNA abundance of Ghr was higher (P <0.0194) in the RT (2.24±0.53) than in the other groups; CT (1.06±0.14); GH (1.06±0.13); and RTGH (0.87±0.10). It is concluded that GH associated or not with resistance exercise does not alter the number of follicles and corpus luteum, or the mRNA abundance of Ghr, Igf1, and Igf2 in the ovaries of rats. However, resistance exercise leads to an increase in gene expression of Ghr in Wistar rat ovaries.