Effect of pharmacological doses of niacin on testicular structure and function in normal and diabetic rats

Male diabetic patients may experience adverse changes in testicular functions or structure. Niacin has antidyslipidemic properties in diabetic patients. We aimed to clarify the effect of pharmacological doses of niacin on testicular structure and function of normal and diabetic rats. Sixty adult male rats were treated as follows. Healthy control (HC); diabetic control (DC); NL and NH groups: normal rats that received niacin at 800 and 4,000 mg/kg of diet; DL and DH groups: diabetic rats that received niacin at 800 and 4,000 mg/kg diet for 50 days. In normal rats, obvious increase in serum testosterone especially in NL group associated with improved antioxidant status of testicular tissue was observed. In diabetic rats, niacin resulted in higher testicular weight/body weight and improved some histological parameters without affecting blood glucose, testosterone and sperm count. Testicular MDA content decreased. In conclusion, niacin especially at 800 mg/kg diet improves serum testosterone levels and antioxidant status of testes in normal rats. In diabetic rats, despite positive changes in histological features and antioxidant status of testes reproductive outcome including sperm count or testosterone levels were not improved. This study set the scene for further investigations on the effect of niacin on male reproductive system.

Recovery effect of pre-germinated brown rice on the alteration of sperm quality, testicular structure and androgen receptor expression in rat model of depression

Depression and antidepressant drugs induce adverse effects in male reproduction. Therefore, it is important to investigate alternative treatment for depression without adverse effects on the male reproductive system. The aim of this study was to determine the effect of pre-germinated brown rice (PGBR) on sperm quality, testicular structure and androgen receptor (AR) expression in rat model of depression. Male Sprague Dawley rats were divided into five groups including control (distilled water only), depression induced by forced swimming test (FST), FST + fluoxetine (antidepressant drug), FST + GABA (gamma-aminobutyric acid) (standard) and FST + PGBR. When compared with the control, sperm motility showed a significant decrease in FST + fluoxetine group. Sperm morphology also decreased significantly in depression and FST + fluoxetine groups. The morphological changes of seminiferous tubules showed significant increases in depression and FST + fluoxetine groups, while AR expression showed significant decreases in depression, FST + fluoxetine and FST + GABA groups. Interestingly, there were no significant differences in all sperm quality parameters, testicular structure and AR expression in FST + PGBR group. These findings reflect the recovery effects of PGBR treatment on sperm quality, morphological changes of seminiferous tubules and AR expression in stress-induced rats. Therefore, PGBR may potentially develop for the treatment for depression without adverse effect on male reproduction.

Comparative testicular structure and spermatogenesis in bony fishes

In most bony fishes, testes are paired elongated organs that are attached to the dorsal wall of the body by a mesorchium. Histological examination of teleost testes, and also in all vertebrates, shows that the testes are formed of germ cells and somatic cells, comprising the germinal and interstitial compartments. Both compartments are separated by a basement membrane. The germ cells may be spermatogonia, meiotic spermatocytes and haploid spermatids that differentiate into spermatozoa. The process of spermatogenesis includes a sequence of morphological and physiological changes of germ cells that begin with the differentiation of spermatogonia that become meiotic spermatocytes. After the second meiotic division, through a process of spermiogenesis, these differentiate into spermatozoa. Spermatogonia associate with Sertoli cells to form spermatocysts or cysts. The cyst is the unit of spermatogenic function, composed of a cohort of isogenic germ cells surrounded by encompassing Sertoli cells. The teleost testis is organized morphologically into 3 types of testis: 1) tubular testis type, present in lower bony fishes as salmonids, cyprinids and lepisosteids; 2) unrestricted spermatogonial testis type, found in neoteleosts except Atherinomorpha; and 3) restricted spermatogonial testis type, characteristic of all Atherinomorpha. The morphology of the testicular germinal epithelium changes during the annual reproductive cycle, reflecting reproductive seasonality.