Effects of Guhanyangshengjing Tablet on Testosterone Synthesis and Expression of SYCP3 in the Testis of Aging Male Rats

Objective: The objective of this article is to investigate the effect of Guhanyangshengjing Tablet (GT) on expression of synaptonemal complex protein 3 (SYCP3), a meiotic marker, in the testis tissue of aging male rats. Methods: Forty aging male rats were randomly assigned into 4 equal groups (n = 10 per group). Rats in each group were treated with GT at dose of 0 (control), 1.5 g/kg, 3.0 g/kg or 4.5 g/kg respectively by gavage daily for 30 days. At the end of the experiment, all animals were sacrificed and the blood samples were drawn to evaluate serum testosterone levels. The reproductive organs of each rat were taken and weighted. The right testis of each rat was removed for the analysis of intratesticular testosterone (ITT) concentrations, and the left one was used for immunohistochemical staining. Results: Compared with the control, reproductive organs’ weights, serum testosterone levels, ITT concentrations, quality of sperm, and expression of SYCP3 in the GT-treated groups were all improved in a dose-dependent manner. Conclusion: GT can improve testosterone synthesis and promote spermatogenesis simultaneously, indicating that GT is suitable for late-onset hypogonadism (LOH) patients with fertility requirements.

Effects of velvet antler polypeptide on sexual behavior and testosterone synthesis in aging male mice

Twenty-four-month-old male C57BU6 mice with low serum testosterone levels were used as a late-onset hypogonadism （LOH） animal model for examining the effects of velvet antler polypeptide （VAP） on sexual function and testosterone synthesis. These mice received VAP for 5 consecutive weeks by daily gavage at doses of 100, 200, or 300 mg kg-1 body weight per day （n = 10 mice per dose）. Control animals （n = 10） received the same weight-based volume of vehicle. Sexual behavior and testosterone levels in serum and interstitial tissue of testis were measured after the last administration of VAP. Furthermore, to investigate the mechanisms of how VAP affects sexual behavior and testosterone synthesis in vivo, the expression of steroidogenic acute regulatory protein （STAR）, cytochrome P450 cholesterol side-chain cleavage enzyme （P450scc）, and 3β-hydroxysteroid dehydrogenase （3βHSD） in Leydig cells was also measured by immunofluorescence staining and quantitative real-time PCR. As a result, VAP produced a significant improvement in the sexual function of these aging male mice. Serum testosterone level and intratesticular testosterone （ITT） concentration also increased in the VAP-treated groups. The expression of STAR, P450scc, and 3β-HSD was also found to be enhanced in the VAP-treated groups compared with the control group. Our results suggested that VAP was effective in improving sexual function in aging male mice. The effect of velvet antler on sexual function was due to the increased expression of several rate-limiting enzymes of testosterone synthesis （STAR, P450scc, and 3β-HSD） and the following promotion of testosterone syothesis in vivo.

Effects of Saikokaryukotsuboreito on Spermatogenesis ant Fertility in Aging Male Mice

Background： Aspermia caused by exogenous testosterone limit its usage in late-onset hypogonadism （LOH） patients desiring fertility. Saikokaryukotsuboreito （SKRBT） is reported to improve serum testosterone and relieve LOH-related symptoms. However, it is unclear whether SKRBT affects fertility. We aimed to examine the effects of SKRBT on spermatogenesis and fertility in aging male mice. Methods： Thirty aging male mice were randomly assigned to three groups, Mice were orally administered with phosphate-buffer solution or SKRBT （300 mg/kg, daily） or received testosterone by subcutaneous injections （10 mg/kg, every 3 days）. Thirty days later, each male mouse was mated with two female mice. All animals were sacrificed at the end of 90 days. lntratesticular testosterone （ITT） levels, quality of sperm, expression of synaptonemal complex protein 3 （SYCP3）, and fertility were assayed. Results： In the SKRBT-treated group, ITT, quality of sperm, and expression of SYCP3 were all improved compared with the control group （ITT： 85.50 ＋ 12.31 ng/g vs. 74.10 ±11.45 ng/g, P = 0.027; sperm number： [ 14.94 ± 4.63] × 106 cells/ml vs. [8.79±4.38] × 106 cells/ml, P = 0.002; sperm motility： 43.16 ± 9.93% vs. 33.51 ± 6.98%, P = 0.015; the number of SYCP3-positive cells/tubule： 77.50 ± 11.01 ng/ml vs. 49.30 - 8.73 ng/ml, P 〈 0.001 ; the expression of SYCP3 protein： 1.23± 0.09 vs. 0.84 ± 0.10, P 〈 0.001 ）, but fertility was not significantly changed （P 〉 0.05, respectively）. In the testosterone-treated group, ITT, quality of sperm, and expression of SYCP3 were markedly lower than the control group （ITT： 59.00 ±8.67, P = 0.005; sperm number： [4.34 ± 2.45] 100 cells/ml, P = 0.018： sperm motility： 19.53 ± 7.69%, P = 0.001 ; the number of SYCP3-positive cells/tubule section 71.98 ：k 8.88%, P= 0.001 ; the expression of SYCP3 protein： 30.00 ± 11.28, P 〈 0.001 ; the percentage of SYCP3-positive tubules/ 0.71± 0.09, P 〈 0.001 ）, and fertility was also suppressed （P 〈 0.05, respectively）. Conclusion： SKRBT had no adverse effect on fertility potential in aging male mice