Various responses of male pituitary–gonadal axis to different intensities of long-term exercise: Role of expression of KNDY-related genes

Abstract

The essential role of regular physical activity has been emphasized for maintaining a healthy life. However, unfortunately, during the last few decades, the lifestyle of people has led to a decrease in physical activity. Research studies have shown that exercise of different intensities is applied on reproductive performance indices, luteinizing hormone (LH) and testosterone (T), with different effects. Nevertheless, the molecular and cellular mechanisms underlying its function are not completely understood. Therefore, this study aimed to evaluate the role of kisspeptin, neurokinin-B and pro-dynorphin (KNDY) gene-expression changes located in the upstream of GnRH neurons in transferring the effects of different long-term exercise intensities on male reproductive axis. Twenty-one adult Wistar rats were randomly divided into control, 6-month regular moderate exercise (RME-6) and 6-month regular intensive exercise (RIE-6). In moderate and intensive exercise groups, rats were treated 5 days a week for 60 min, at 22 and 35 m/min, respectively. Finally, the hypothalamic arcuate nucleus was isolated and the relative gene expression of kisspeptin (Kiss1), neurokinin-B (Nkb), pro-dynorphin (Pdyn) and gonadotropin-releasing hormone (Gnrh) genes were measured by realtime polymerase chain reaction method. The results showed that RIE-6 treatment decreased Gnrh and increased Pdyn mRNA levels in the arcuate nucleus. Furthermore, although RME-6 treatment decreased Nkb and increased Pdyn mRNA levels, the Gnrh mRNAwas not affected. Regarding the Gnrh mRNA levels and serum concentrations of reproductive indices (LH and T), moderate exercise did not impose harmful effects on the hypothalamic-pituitary-gonadal axis than intensive exercise. The different impacts of diverse long-term exercise intensities on the male pituitary-gonadal axis maybe relay by the various changes in hypothalamic Nkb and Pdyn gene expressions.

Short-term regular moderate exercise improved male hypothalamic-pituitary-gonadal axis function via the reduction of hypothalamic neurokinin B expression in adult rats

“…The Kiss1 gene expression in the regular moderateand intensive-exercise groups showed no significant difference, compared to control rats. Khajehnasiri et al (2018) reported that long-term physical activity can not alter Kiss1 gene expressions, which is in line with present results. Therefore, these findings indicated that kiss1 mRNA level was not affected by different intensity and duration of physical activity.…”

“…Accordingly, based on the findings, the arcuate Nkb mRNA level was mainly associated with the exercise intensity rather than its duration. Concerning the effect of moderate exercise for one month, these results are similar to the findings of our previous study, in which treatment of rats with moderate exercise for six months decreased Nkb mRNA expression in the arcuate nucleus (Khajehnasiri et al, 2018).…”

“…According to the obtained data, Pdyn gene expression was not affected by short-term moderate and intensive exercise. However, our previous study suggested that long-term intensive and moderate exercise caused enhanced Pdyn mRNA expression in the arcuate nucleus (Khajehnasiri et al, 2018). Consequently, based on this finding, the arcuate Pdyn mRNA level was mostly associated with the exercise duration rather than its intensity.…”

“…For evaluation molecular test, an arcuate nucleus was extracted from the brain hypothalamus based on a previous method (Khajehnasiri et al, 2018;Molaei et al, 2020). Briefly, YTzol Pure RNA buffer (Yekta Tajiz, Iran) removed total RNAs from samples.…”

Control of Protein and Energy Metabolism in the Pituitary Gland in Response to Three-Week Running Training in Adult Male Mice

“…On the histological level in rats, physical activity induced specific adaptations in somatotropic cells, including increased cell size and the production of larger secretory granules [5]. Exercise in different experimental settings also affected the pituitary-gonadal [6], pituitary-adrenal [7], and pituitary-thyroid [8] hormone axes.…”