Effects of administering Tu-Chung extract on the gonadal and adrenal system in rats during exercise / 体力科学

ABSTRACT

This study examined the secretion capacity of the gonadal and adrenal cortex systems and the morphology of the adrenal cortex in male rats treated with Tu-chung (Eucommia ulmoides O<SUB>LIV</SUB>) extract, the main component of Tu-chung extract, geniposide, or both agents during exercise load testing.<BR>Twenty-four 4-week-old male Wistar rats were used. The rats were divided into four groups those treated with Tu-chung extract and geniposide (n=7), those treated with Tu-chung extract (n=6), those treated with geniposide (n=7) and a control group treated with distilled water. The dose of each agent was 0.1 ml/100g body weight. The agents were administered orally for 25 days. For the exercise load test, a treadmill for small animals was used, with a tilting angle set at 0. Exercise load testing was performed for 30 min (2-min warm up and 28-min running) daily for 25 days. The running speed was 20 m/min for the first 5 days, and then increased by 5 m/min every 5 days.<BR>The following results were obtained.<BR>1. The relative weight of the adrenal gland (gland weight/100 g body weight) in the group treated with Tu-chung extract and geniposide was significantly higher than that in the group treated with geniposide or the control group (p<0.01) . The relative weight of the adrenal gland in the group treated with Tu-chung extract was significantly higher than that in the group treated with geniposide or the control group (p<0.01, p<0.001) . Furthermore, the relative gland weight in the group treated with geniposide was significantly higher than that in the control group (p<0.05) .<BR>2. In the group treated with Tu-chung extract and geniposide, the group treated with Tu-chung extract and the group treated with geniposide, the relative gland weight of the testis (testis weight/100g body weight) was significantly higher than that in the control group (p<0.001) . However, there were no significant differences among the three groups.<BR>3. The 24-h urinary excretion of 17-ketosteroid (17-KS) in the group treated with Tu-chung extract and geniposide was significantly higher than that in the group treated with Tu-chung extract, the group treated with geniposide or the control group (p<0.01, p<0.01, p<0.001) . In the group treated with geniposide, the 24-h urinary excretion of 17-KS was significantly higher than that in the control group (p<0.05) .<BR>4. In the three groups treated with Tu-chung extract and/or geniposide, serum testosterone levels were significantly higher than those in the control group (p<0.001, p0.05, p<0.05) .<BR>5. Concerning the morphology of the adrenal cortex, the thickness of the reticular layer of the adrenal cortex was most markedly increased in the group treated with Tu-chung extract and geniposide, followed in order by the group treated with Tu-chung extract, the group treated with geniposide and the control group.<BR>Administration of Tu-chung extract and the main component of Tu-chung extract, geniposide, during exercise load testing significantly increased the weights of the adrenal gland and testis, and promoted testosterone secretion in the adrenal cortex reticular layer and testis.<BR>These findings suggest that geniposide plays an important role in the pharmacological action of Tu-chung.