Effect of calcium channel blockers on increased plasma testosterone level induced by arecoline in male albino rats

Background: Arecoline is one of the major components of betel nuts, which have been consumed as chewing gum in Southeast Asia. Arecoline might affect the endocrine system but the mechanism is still unclear.Some studies suggest that calcium channels may play a role in this effect. Aim: The present study was carried out to investigate the effect of calcium channel blockers on increased plasma testosterone level induced by Arecoline of betel nuts in rats. Methods: 80 male albino rats were divided into 8 equal groups as follows: control group; arecoline group; Human chorionic ganadotropin (HCG) group; arecoline + HCG group; nifedipine group; nifedipine + arecoline group; tetrandrine group and tetrandrine + arecoline group. After 2 hours of injection, rats were sacrificed and blood samples were collected and plasma was separated for determination of testosterone, androstendione and leutinizing hormone (LH). Results: Arecoline with and without HCG resulted in significant increase of plasma testosterone and androsteindione, and only significant increase after HCG injection of LH levels. Injection of nifedipine or tetrandrine alone caused non-significant change in plasma testosterone and androsteindione compared with the control group. Injection of nifedipine or tetrandrine with arecoline resulted in significant reduction in plasma testosterone and androsteindione levels compared with arecoline treated group. Conclusion: Arecoline caused significant increase in testosterone secretion in male albino rats that may be due to calcium channel activation in Leydig cells.