Journal of Rafsanjan University of Medical Sciences

Effects of Tamsolusin on Serum Testosterone and Gonadotropins Concentration in Adult Male Rats

 M. Mokhtari PhD , M. Shariati PhD , J. Amiri MSc

Received: 06/06/06 Sent for Revision: 18/10/06 Received Revised Manuscript: 25/11/06 Accepted: 27/01/07

Background and Objective: Tamsulosin hydrochloride (HCl) is an alpha-1 adrenoceptor antagonist and its ability to inhibit alpha-1 adrenoceptor is more than alpha-2 adrenoceptor. Due to the important therapeutic role of Tamsulosin HCl in benign prostatic hyperplasia (BPH), its side effects on the endocrine axes are also very important. The aim of the present research was to determine the effect of Tamsulosin HCl on serum level of testosterone and gonadotropins , and also on the spermatogengsis in adult male rats .

Materials and Methods: In this experimental study, 40 adult male Wistar rats were randomly divided into 5 groups of 8. The experimental groups received 100, 300, and 600 mg/kg/day of Tamsulosin for 28 days. The sham group were treated with distilled water and the control group received nothing. The blood samples were taken on day 28 and the blood concentration of LH, FSH and testosterone were measured by RIA. Simulataneously, the testes of all rats were removed to assess the possible histological changes. The results were analysed using ANOVA and Duncan tests. The level of significance was considered at p≤0.05.

Results: The results indicated that at doses used in our study, Tamsulosin HCl had no significant effect on serum LH and FSH. However, this drug at high concentration was able to decrease the level of testostrone. Also, our histological studies showed a decrease in density of spermatoza in the seminiferous tubules in some sections only at high doses of the drug.

Conclusion: According to this research and the results from other similar studies, Tamsulosin at high dose is possibly able to decrease the serum oncentration of testostrone through either the effect on steroidogenesis enzymes in testes, or its inactivation properties on adrenergic and serotonergic systems involved in steroidogenesis. So, it seems that alpha adrenergic receptor blockers possibly have some deleterious effect on spermatogenesis causing infertility in male rats. However further studies need to confirm these results.

 Key words: Tamsulosin, Testosterone, Gonadotropins, Rats