Carnosine mitigates apoptosis and protects testicular seminiferous tubules from gamma-radiation-induced injury in mice.

This study investigated the radioprotective effects of a naturally occurring dipeptide, carnosine, on testicular damage. Carnosine was administered (10, 50 and 100 mg kg(-1) body weight) to male mice via intraperitoneal injection for 4 days prior to gamma irradiation (2 Gy). Apoptosis with the TUNEL assay and histopathological parameters were evaluated 12-h and 14-day post-irradiation. Pre-treatment with carnosine before irradiation significantly reduced the frequency of TUNEL-positive cells induced by radiation treatment at all doses by reduction factors of 1.8, 2.47 and 2.23 for carnosine at 10, 50 and 100 mg kg(-1) bw, respectively, unlike that observed in the radiation alone group. Exposure to ionising radiation decreased sperm count and reduced the height and diameter of seminiferous epithelial tubules. Pre-treatment with all doses of carnosine significantly augmented seminiferous epithelial height and tubule diameter and also increased the number of germinal cells in comparison to the group treated with radiation only. These results indicate that carnosine prevents testicular dysfunction induced by gamma-irradiation via an anti-apoptotic effect; this restoration of proper testicular function ultimately leads to the recovery of spermatogenesis.

Effect of aminoguanidine in sperm DNA fragmentation in varicocelized rats: role of nitric oxide.

BACKGROUND AND PURPOSE: The sperm of infertile men with varicocele exhibit markedly high DNA damage that appears to be related to high oxidative stress (OS). Aminoguanidine (AG) is a specific inhibitor of the nitric oxide synthase (NOS) isoforms iNOS and an antioxidant, the effects of which decrease NO and peroxynitrite production. The aim of this study was to determine the effects of AG on sperm chromatin in varicocelized rats. METHODS: Thirty male Wistar rats were divided into 5 groups: control, sham, varicocele, and AG and placebo-treated groups. At 10 weeks after varicocele induction, sperm chromatin was evaluated in all groups, except in the treated groups. The treated groups received intraperitoneal injections of 50 mg/kg AG or placebo daily for 10 weeks and then were killed for chromatin assessment. Sperm chromatin was evaluated by aniline blue, acridine orange, toluidine blue, and chromomycin A(3) staining. RESULTS: The results of the 4 above tests were significantly increased between varicocele and control (and sham) groups (P < .05). CONCLUSION: The findings of this study suggest that AG improves sperm DNA fragmentation that is associated with infertility in varicocelized rats, and treatment with AG can reduce the damage to sperm DNA.

Histomorphometric alteration of knee articular cartilage and serum alkaline phosphatase in young female mice by chronic supplementation with soybean.

The purpose of the present study was to examine the effect of soybean supplementation on cartilage thickness in the knee joint and serum levels of alkaline phosphatase (ALP) in mice. Forty female mice were fed for 6 months on one of four regimens: low protein, complete protein without soybean, and complete protein containing either 20% or 40% soybean. Body weight differences, histological and histomorphometric analysis, and ALP levels were determined and compared after 6 months. The results showed a significant increase in serum ALP activity and cartilage thickness in both groups fed on soybean-containing diets, compared with the other groups. Additionally, the number of chondrocytes was significantly increased (p < 0.001) in the group taking the 40% soybean regimen, and the proteoglycan content of the intracellular fluid in the tibia was higher in those groups taking soybean. In conclusion, the present study suggests that soybean supplementation is capable of stimulating ALP production and reducing cartilage loss in young female mice. Soybean supplementation during childhood may therefore be potentially useful in protecting joints.