Combined Effects of Intermittent Hypoxia and Exercise on the Production of Testosterone in Male Rats

Chih-Chieh Chen ； Jou-Chun Chou ； Tsung-Hsien Kuo ； Po-Han Lin ； Cai-Yun Jian ； Paulus S. Wang ； Chien-Wei Chen

《Adaptive Medicine》 12卷3期 (2020/09) Pp. 64-70

https://doi.org/10.4247/AM.2020.ACA249

摘要

It has been reported that either acute exercise or intermittent hypoxia (IH) increases the release of testosterone, yet little is known regarding their combined effects. This study was therefore designed to investigate the combined effects of acute exercise and IH on the production of testosterone. Male rats were housed in hypoxia chambers (12% O_2, 8 h per day) for 3 or 6 days, and then catheterized via right jugular vein 2 h before 30 min swimming exercise. The normoxic rats were used as control group. Blood was collected 0, 15, 30, 60 and 120 min after swimming. The plasma samples of each rat were separated for measurement of glucose, lactate and testosterone. In the in vitro study, rat Leydig cells were incubated with human chorionic gonadotropin (hCG, 0.05 iu/ml ), forskolin (10^(-5) M) or sodium lactate (1-10 mM ) at 34°C for 1 h. The concentrations of testosterone in plasma and medium samples were detected by radioimmunoassay. The treatments showed that swimming for 30 min increased levels of glucose, lactate and testosterone in normoxic and 3-day IH rats. In contrast, levels of plasma glucose and lactate in response to swimming were reduced by treatment of 6-day IH. IH for 6 days enhanced basal levels of testosterone, but abolished the peak level of testosterone in response to swimming. The basal level and forskolin as well as hCG-evoked release of testosterone in vitro from Leydig cells were elevated by the administration of either 3-day or 6-day IH. The testosterone release in vitro from Leydig cells of normoxic rats was dose-dependently increased by incubation of sodium lactate, whereas IH for 3 or 6 days attenuated or abolished the testosterone response to lactate, respectively. The above findings suggested that the abolished release of testosterone in response to acute exercise or lactate caused by chronic IH might be the result of IH inhibition on the stimulatory effect of lactate on testosterone production.

關鍵字

hypoxia ； lactate ； Leydig cells ； swimming ； testosterone