Isozymes of glutathione peroxidase in cow ovarian tissue under different physiological and pathological states of the gonad

The article presents a study of glutathione peroxidase (GPO) isozymes content in ovarian tissue under various physiological and pathological states of cow gonads. The ovarian tissue of 12 cows in different physiological conditions were selected for research, from which homogenates were prepared. The content of isozymes was determined in the supernatant after centrifugation by electrophoresis. After electrophoresis in a 7.5 % polyacrylamide gel and specific staining of the plates according to Lin C. L. and Weydert C. J., 5 bands of catalytically active isozymes of the enzyme (GPO1, GPO2, GPO3, GPO4, and GPO5) were established. They differed in electrophoretic mobility, intensity, and area of band staining. It has been proven that depending on the physiological state of the ovaries, the content of individual isozymes in the gonad tissue changed. In particular, it was found that the content of GPO1 for “late corpus luteum” and “follicular growth” was almost the same, and was in the range of 14.2–15.6 %, and for “early corpus luteum” it was 8.7–10.1 % lower (Р < 0.01). The content of GPO2 was high in “early corpus luteum” (19.9 ± 6.42 %), and in “late corpus luteum” and “follicular growth” it was lower on 11.0–13.2 % (Р < 0.01). The content of GPO3 during “follicular growth” and “early corpus luteum” was within 50.1–51.2 %, and during “late” it decreased on 4.5–5.6 %. According to changes in the physiological state of the ovary in the tissue of “late corpus luteum”, the content of GPO4 was the highest (26.0 ± 2.40 %), and under “follicular growth” and “early corpus luteum” it was lower on 10.2 (Р < 0.05) and 12.9 % (Р < 0.01), respectively. A high content of GPO5 was established in the ovarian tissue of “follicular growth” (10.8 ± 2.00 %), which tended to decrease by 2.8 % and by 4.8 %, respectively, in “early” and “late corpus luteum”. For ovarian tissue with hypofunction, compared to physiological conditions, a probable decrease in the content of the following isozymes was registered: GPO1 by 1.2–11.3 % (Р < 0.01), GPO4 – 6.8–19.7 % (Р < 0 .01) and GPO5 – 2.7–7.5 % (Р < 0.01), while the content of GPO3, on the contrary, increased by 23.6–29.2 % (Р < 0.05–0.01). The study of the dependence of the content of enzyme isozymes on different conditions of the gonad showed that the correlation ratio for the content of GPO isozymes in ovarian tissue under physiological conditions and hypofunction: medium strength was negative for GPO2 and GPO3 (η = 0.473 and 0.530), positive for GPO5 (η = 0.481 ), and strongly positive for GPO1 and GPO4 (η = 0.740 and 0.746).