272 EFFECT OF DIETARY RESTRICTION ON SPERM CHARACTERISTICS AND OXIDATIVE STATUS ON TESTICULAR TISSUE IN YOUNG RATS EXPOSED TO LONG-TERM HEAT STRESS

Abstract

The objective was to evaluate effects of dietary restriction on oxidative status and sperm parameters in rats exposed to long-term heat stress. Forty healthy Sprague-Dawley rats (2.5 months old) were equally allocated into 4 groups (with respect to diet and temperature): room temperature (22°C)-ad libitum; room temperature-dietary restriction (40%); high temperature (38°C)-ad libitum; and high temperature-dietary restriction. At the end of the 9th week, some oxidants (lipid hydroperoxide, total oxidant status, oxidative stress index) and some antioxidants (total antioxidant status, sulfhydryl groups, ceruloplasmin, paraoxonase and arylesterase activities) were measured in testicular tissues. In addition, concentration, motility, volume, abnormal sperm count, acrosome and membrane integrity of epididymal sperm were also evaluated. All data were analysed by 2-way ANOVA (P < 0.05). High temperature did not significantly affect most oxidative and antioxidative parameters (except for sulfhydryl groups and ceruloplasmin), yet it impaired all sperm values. Neither sperm values nor oxidative status, with the exception of sulfhydryl groups, ceruloplasmin and arylesterase in the testis tissue, were significantly affected by dietary restriction. We concluded that long-term heat stress did not significantly affect testicular oxidative status in young rats, although sperm were sensitive to heat stress. Furthermore, dietary restriction failed to improve sperm quality and oxidative status, except some individual antioxidant parameters in young rats exposed to long-term heat stress.