Abstract: AIM:to evaluate the cytotoxic effects of Hydroxyurea (HU) in vitro employing rat testicular Sertoli-germ cell coculture. METHODS:Cytotoxic changes induced by HU (0, 10^-3, 10^-2, 10^-1mol/L)in mixed cultures of Sertoli and germ cells were seen at 96 h after treatment, respectively. And 10^-2 mol/L HU were added to the culture, at 24, 48, 72 and 96 h after treatment, respectively. RESULTS:HU led to an increase in germ cell detachment from the Sertoli cell monolayer in a dose dependent manner. Detached cells were observed and the viability of detached cells was decreased in 10^-3 mol/L and above treated groups. Substantial leakage of the cytosolic enzyme lactate dehydrogenase (LDH) was observed in the medium after 96 h HU treatment at concentrations of 10^-2mol/L and above treated groups. The same, HU exposure led to an increase in germ cell detachment, the leakage of LDH, a decrease in cell viability from the Sertoli cell monolayer in a time dependent manner compared with the control culture. CONCLUSION:It is shown that HU exhibited an obvious toxicity to the germ cells of male rats in Sertoli cell germ cell co-culture model.

Key words: hydroxyurea, Sertoli-germ cell, coculture, cytotoxity