Influence of hCG on inducible nitric oxide synthase gene expression in ram testicular arteries

Background. Experimental evidence suggests a relationship between the vasodilatory effect of hCG and the NOS system in the testis. The influence of hCG administration on testicular vascular NOS gene expression has not been fully investi- gated. Objective: This study aimed to evaluate the pres- ence of the nitric oxide syntheses gene in ram testicular arteries and the influence of hCG administration on its expression. Materials and methods: Both testicular arteries of sixteen rams were extracted before and after i.v. administration of 5000 IU of hCG or placebo. The expression of the iNOS gene was investigated by real time PCR. Data were analyzed by means of Wilcoxon and Mann-Whitney tests. A p value of < 0.05 was considered statistically sig- nificant. Results: PCR revealed the presence of iNOS mRNA in all basal samples but the expression of the iNOS gene was significantly reduced in all arteries obtained 24 h after the administration of either hCG or placebo. A signifi- cant reduction in the expression of iNOS gene was observed in the testicular arteries extracted after 24 h in both treated and placebo groups. On the other hand hCG stimulation did not significantly influence iNOS expres- sion following its administration compared to a placebo. Conclusion: Ram testicular arteries express the iNOS gene but hCG stimulation did not significantly influence iNOS expression. A significant reduction in the expres- sion of this gene was observed in the testicular arteries extracted after 24 h in both treated and placebo groups, suggesting that iNOS expression on the testicular artery could be influenced by the spermatic vessel ligation of the controlateral testis.