Comparison of oxidant and antioxidant status of seminal plasma and spermatozoa of several fish species

Oxidant and antioxidant activity in seminal plasma was compared with that in spermatozoa of teleost (common carp Cyprinus carpio and brook trout Salvelinus fontinalis) and chondrostean (Russian sturgeon Acipenser gueldenstaedtii, Siberian sturgeon Acipenser baerii, and sterlet Acipenser ruthenus) fishes. No differences were found between seminal plasma and spermatozoa in the level of thiobarbituric-acid-reactive substance (0.24 ± 0.08 to 0.33 ± 0.04 nmol/mg proteins) in Russian sturgeon, Siberian sturgeon, and sterlet. Carbonyl protein concentration was significantly higher in spermatozoa than in seminal plasma of all studied species. Analyzed antioxidants included superoxide dismutase, glutathione reductase, and glutathione peroxidase activity. Significant differences (P < 0.05) were detected between seminal plasma and spermatozoa in total superoxide dismutase (SOD) and glutathione reductase (GR). Total glutathione peroxidase (GPx) activity was significantly higher in brook trout (12.56 ± 3.23 mU/mg proteins) and Russian sturgeon (11.56 ± 3.12 mU/mg proteins) spermatozoa compared to seminal plasma (6.81 ± 1.56 mU/mg proteins in brook trout and 9.56 ± 3.12 mU/mg proteins in Russian sturgeon). This study provides new data on oxidant and antioxidant balance between spermatozoa and seminal plasma that may be of value in the development of methods for artificial reproduction of teleost and chondrostean species.