Effects of Inhibitory and Stimulatory Administration of Nitric Oxide Synthesis on the Zona Pellucida Thickness of Ovarian Follicles in Pregnant Rats

Nitric oxide is a short-lived mediator which produced in different mammalian cell types. Nitric oxide synthesizes (NOSs) are a family of complex enzymes that catalyze the oxidation of L-Arginine to form Nitric Oxide. Overproduction of nitric oxide may imply in the pathogenesis of several immune diseases. The present study demonstrates the potential role of nitric oxide in zona pellucida thickness. This study was performed on 8 weeks pregnant Wistar rats (n=32). To study the impact of Nitric Oxide on zona pellucida thickness four experimental designs were investigated. Control group, 200 mg/kg L-Arginine, 20 mg/kg L-NAME and a combination of L-Arginine, and L-NAME. Ovary removal via laparotomy was performed 13 days after intraperitoneal injection. Zona pellucida thickness was investigated by Image tools III quantitative technique. Based on our findings, L-Arginine causes a significant decrease in zona pellucida thickness (p ≤ 0.05). No discrepancy was detected in zona pellucida thickness between the other experimental groups and the control group. The results support the hypothesis that destructive effects on ovary and zona pellucida formation can be mediated by the overproduction of nitric oxide.