Effect of zinc chloride on anxiety and its interaction with the androgenic system in adult male rats

Introduction: Previous studies have shown that zinc deficiency and castration could increase anxiety, while administration of zinc or testosterone has anxiolytic effects. This study examined the effect of zinc chloride administration on anxiety in gonadectomized male rats. Methods: For this purpose, adult male Wistar rats (weighing 200-250 g) were castrated. One month after surgery, different doses of zinc chloride (0, 5, 7.5 and 10 mg/kg IP) were administered 30 min before the elevated plus maze test. Time spent and the number of entries in open arms was recorded as measures of anxiety and the number of closed arm entries recorded as locomotor activity. Results: 1) Zinc chloride significantly decreased the time spent and the number of entries in the open arms in gonadectomized rats compared to the control group. 2) Zinc chloride administration could not decrease anxiety, even in the testosterone pretreated gonadectomized male rats. Conclusion: Our findings showed that zinc significantly increased anxiety in gonadectomized rats. Since our previous findings showed that zinc chloride decreased the anxiety level in intact male rats, it seems that zinc chloride effects on anxiety would change in relation to the presence or absence of the gonads and it might interact with androgenic system through an effect on the testis.