Preventive Effects of Resistance Training on Hemodynamics and Kidney Mitochondrial Bioenergetic Function in Ovariectomized Rats

Abstract

Menopause occurs due to the depletion of the ovarian reserve, leading to a progressive decline in estrogen (E2) levels. This decrease in E2 levels increases the risk of developing several diseases and can coexist with chronic kidney disease (CKD). Arterial hypertension (AH) is another condition associated with menopause and may either contribute to or result from CKD. Ovariectomy (OVX) induces hypoestrogenism, which can lead to mitochondrial bioenergetic dysfunction in the kidneys. Previous studies have suggested that exercise training has beneficial effects on adults with CKD and AH. To investigate the effects of OVX and resistance training (RT) on hemodynamic parameters and mitochondrial bioenergetic function of the kidney, female Wistar rats were divided into ovariectomized (OVX) and intact (INT) groups. These rats were either kept sedentary (SED) or subjected to RT for thirteen weeks. The RT involved climbing a vertical ladder with a workload apparatus. Hemodynamic parameters were assessed via tail plethysmography. Mitochondrial respiratory function was evaluated with high-resolution respirometry. Gene expression related to the electron transport chain (ETC) and oxidative phosphorylation (OXPHOS) was evaluated by real-time qPCR. At week 13, key hemodynamic parameters (systolic blood pressure and mean arterial pressure) were significantly elevated in the OVX-SED group. Compared with those in the other groups, mitochondrial bioenergetics were impaired in the OVX-SED group. In contrast, the trained groups presented improved mitochondrial bioenergetic function compared with the sedentary groups. OVX led to reduced gene expression related to the mitochondrial ETC and OXPHOS, whereas RT both prevented this reduction and increased gene expression in the trained groups. Our results indicate that hypoestrogenism significantly decreases OXPHOS and ETC capacity in the kidneys of sedentary animals. However, RT effectively increased the expression of genes related to mitochondrial ETC and OXPHOS, thereby counteracting the effects of OVX.