Dehydroepiandrosterone Supplementation Combined with Whole-Body Vibration Training Affects Testosterone Level and Body Composition in Mice

Abstract

Dehydroepiandrosterone (DHEA), the most abundant sex steroid, is primarily secreted by the adrenal gland and a precursor hormone used by athletes for performance enhancement. Whole-body vibration (WBV) is a well-known light-resistance exercise by automatic adaptations to rapid and repeated oscillations from a vibrating platform, which is also a simple and convenient exercise for older adults. However, the potential effects of DHEA supplementation combined with WBV training on to body composition, exercise performance, and hormone regulation are currently unclear. The objective of the study is to investigate the effects of DHEA supplementation combined with WBV training on body composition, exercise performance, and physical fatigue-related biochemical responses and testosterone content in young-adult C57BL/6 mice. In this study, male C57BL/6 mice were divided into four groups (n = 8 per group) for 6-weeks treatment: sedentary controls with vehicle (SC), DHEA supplementation (DHEA, 10.2 mg/kg), WBV training (WBV; 5.6 Hz, 2 mm, 0.13 g), and WBV training with DHEA supplementation (WBV+DHEA; WBV: 5.6 Hz, 2 mm, 0.13 g and DHEA: 10.2 mg/kg). Exercise performance was evaluated by forelimb grip strength and exhaustive swimming time, as well as changes in body composition and anti-fatigue levels of serum lactate, ammonia, glucose, creatine kinase (CK), and blood urea nitrogen (BUN) after a 15-min swimming exercise. In addition, the biochemical parameters and the testosterone content were measured at the end of the experiment. Six-week DHEA supplementation alone significantly increased mice body weight (BW), muscle weight, testosterone level, and glycogen contents (liver and muscle) when compared with SC group. DHEA supplementation alone had no negative impact on all tissue and biochemical profiles, but could not improve exercise performance. However, WBV+DHEA supplementation also significantly decreased BW, testosterone level and glycogen content of liver, as well as serum lactate and ammonia levels after the 15-min swimming exercise when compared with DHEA supplementation alone. Although DHEA supplementation alone had no beneficial effect in the exercise performance of mice, the BW, testosterone level and glycogen content significantly increased. On the other hand, WBV training combined with DHEA decreased the BW gain, testosterone level and glycogen content caused by DHEA supplementation. Therefore, WBV training could inhibit DHEA supplementation to synthesis the testosterone level or may decrease the DHEA supplement absorptive capacity in young-adult mice.

Keywords: dehydroepiandrosterone (DHEA); exercise performance; glycogen.; testosterone; whole-body vibration (WBV).

Figure 1

Protocol for 6-week whole-body vibration training (WBV).

Figure 2

Effect of DHEA supplementation combined with WBV training on body weight (BW) for 6 weeks. Data were mean ± SEM (n = 8). * p < 0.05 for DHEA, WBV and WBV+DHEA groups, respectively, compared with SC group by one‐way ANOVA.

Figure 3

Effect of 6-week DHEA, WBV, and WBV+DHEA on forelimb grip strength (a) and swimming exercise performance (b). Male C57BL/6 mice underwent a grip strength test 1 h after the final administered DHEA or WBV training. Swimming performance test were pretreated with DHEA or WBV training and then 1 h later performed an exhaustive swimming exercise with a load equivalent to 5% of the mouse's body weight attached to the tail. Data were mean ± SEM (n = 8). Different letters indicated significant difference at p < 0.05 by one-way ANOVA.

Figure 4

Effect of 6-week DHEA, WBV, and WBV+DHEA on serum testosterone level. Data were mean ± SEM (n = 8). Different letters indicated significant difference at p < 0.05 by one-way ANOVA.

Figure 5

Effect of 6-week DHEA, WBV, and WBV+DHEA on serum levels of (a) lactate, (b) ammonia (NH3), (c) glucose, (d) creatine kinase (CK), and (e) blood urea nitrogen (BUN) after an acute exercise challenge. Mice were pretreated with of DHEA, WBV, or WBV+DHEA for six weeks, then 1 h later performed a 15-min swimming test without weight loading. Data were mean ± SEM (n = 8). Different letters indicated significant difference at p < 0.05 by one-way ANOVA.

Figure 6

Effect of 6-week DHEA, WBV, and WBV+DHEA on (a) hepatic glycogen and (b) muscle glycogen levels at rest. Data were mean ± SEM (n = 8). Different letters indicated significant difference at p < 0.05 by one-way ANOVA.

Figure 7

The H&E staining of 6-week DHEA, WBV, and WBV+DHEA on the morphology of (a) liver, (b) skeletal muscle, (c) heart, (d) kidney, (e) lung, and (f) epididymal fat pad (EFP) tissues. Specimens were photographed with a light microscope (Olympus BX51). (Magnification: ×200, Scale bar, 40 µm).

Figure 8

The immunohistochemical (IHC) staining of 6-week DHEA, WBV, and WBV+DHEA on type I and type II muscle fibers in gastrocnemius muscle. Red fibers are type I fibers; orange fibers are type II fibers. Specimens were photographed by light microscopy. (Magnification: ×200, Scale bar, 40 µm).

Figure 9

The proposed mechanisms by which DHEA supplementation combined with WBV training acts on the hormone regulation.