ANDROLOGIA zyxwvutsrqponm 31, zyxwvutsrqp 83-90 (1999) ACCEPTED: zyx JUNE 16, 1998 Changes in rat testicular antioxidant defence profile as a function of age and its impairment by hexachlorocyclohexane during critical stages of maturation L. Samanta, A. Roy and G. B. N. Chainy Biochemistry Unit, Department of Zoology, Utkal University, Bhubaneswar, India Key words. Testis-hexachlorocyclohexane-lipid peroxidation-antioxidant enzymes-ATPase-spermatogenesis Summary. Age-related changes in rat testicular oxidative stress parameters were investigated. A biphasic pattern was evident for lipid peroxidation and for the activity ratio of superoxide dismutase to cdtalase and glutathione peroxidase with increasing age. In the first phase of life (birth- 7 days), a linear fall in lipid peroxidation was accompanied by a gradual increase in the enzyme ratio which was reversed in the second phase (1 5-600 days). Glutathione and ascorbic acid levels increased from birth to the 45th day and remained unchanged up till 365days and then reduced at 600 days of age. The maximum level of H,02 observed at birth gradually decreased till 90 days and remained unchanged up till 365 days of age; thereafter its level was elevated on day 600. The results suggest that an antioxidant defence system plays a crucial role in development and maturation of the rat testis. When the rats were treated with hexachlorocyclohexane during critical stages of testicular development (6th-30th day) and responses were evaluated on the 46th day of age, elevations in the levels of testicular lipid peroxidation and H202 along with reduction in levels of superoxide dismutase, catalase and ascorbic acid were observed. However, no change in glutathione and its metabolizing enzymes was recorded. On the other hand, hexachlorocyclohex- ane elevated total testicular Ca2 +-Mg2 +-ATPase activity. The results advocate for impairment of testicular functions in adult age as a consequence of some permanent lesions induced by hexachloro- cycloliexane during critical stages of sexual maturation. Correspondence: Prof. G. B. N. Chainy, Biochemistry Unit, Department of Zoology, Utkal University, Bhubaneswar- zyxwvut 75 1 004, India. Introduction The developing testis is distinctively different from that of the mature one, because extensive morpho- logical, physiological and biochemical changes take place during sexual maturation. Recently, Peltola et zyxwvut al. (1992) have described the develop- mental profiles of rat testicular antioxidant enzymes from 6 to 240days of age. However, information on changes in isoenzymes of superox- ide dismutase (SOD) and glutathione peroxidase (GPx) along with lipid peroxidation (LPX) in the testis with respect to development and ageing is still needed. In the present study, developmental profiles of antioxidant enzymes, two nonenzymatic antioxidants (reduced glutathione and ascorbic acid), LPX and H202 in the testis of the rat from birth to 600 days of age were estimated to con- struct a composite picture of dynamic changes taking place in antioxidant profile of the testis during sexual maturation and ageing. Earlier it was reported that hexachlorocyclohex- ane (HCH), an organochlorine pesticide, induces oxidative stress in the testis and the magnitude of induction is higher in the case of immature rats than the mature ones (Samanta & Chainy, 1997). Similarly, alteration in the mitochondrial ATPases of the rat testis to HCH is more pronounced in immature rats than their mature counterparts (Roy & Chainy, 1996). In the present study, in order to understand the impact of HCH exposure during critical stages of testicular development, rats were exposed to HCH during critical stages of sexual maturation (from 6 to 30 days of age) and changes in oxidative stress parameters and mitochondrial Ca2 +-Mg*+-ATPases in the testis were recorded on the 46th day (onset of reproductive capacity) of age. US. Copyright Clearance Center Code Statement: 0303-4569/99/3 102-0083 $14.00/0