The Age-related Changes in SOD Activity in Bovine (Bos taurus) Reproductive Organs

Background: The appearance of reactive oxygen species (ROS) is connect with oxidative energy production particularly in reproductive organs. They characterize by increased metabolism, which may change during ageing. Their increase could be dangerous for germ cells. That is why the antioxidant protection is need. One of the main antioxidative enzyme is superoxide dismutase (SOD) which could be regulated by steroid hormones through genomic mechanism of action. But their level changed during ageing and maturation. However, there is still lack information about ageing alteration of SOD activity in bovine especially in reproductive organs. Materials, Methods & Results: The material for experiment consisted of reproductive organs: uterus (which was separated into endometrium and myometrium), both ovaries and corpus luteum collected immediately after slaughter at the slaughterhouse. Samples were taken from healthy cows aged between 16-24 months (n = 15) during luteal phase of cycle and female calves aged between 2 weeks and 2 months (n = 12) Total SOD activity was measured in homogenates of reproductive organs by use of the spectrophotometric method. PAGE electrophoresis was performed and Western blotting technique with specific anti-SOD antibodies as well as zymography confirmed the presence of enzymatic protein and the activity of SOD isoenzymes. The results of spectrophotometric determinations showed significant influence of age on SOD activity in examined tissues. The SOD activity not indicate significant differences between examined reproductive organs in the group of cows but higher level was noticed in myometrium while the lowest in corpus luteum but the differences between ovaries in cows were not observed. In the group of female calves as well as in the group of cows the differences between SOD activity in reproductive organs were not observed. The higher level was noticed in ovaries but the lower level was observed in myometrium. The SOD activity was 2-fold higher in calves compared to cows with statistically significance (P < 0.05). Further experiments are necessary to confirm the importance and involvement of SOD in reproductive maturation and aging. Discussion: The present study describes the activity and the presence of the enzymatic protein of the antioxidative enzyme SOD in reproductive organs in premature and mature cows. In present investigation the SOD activity was 2-fold higher with statistically significance (P < 0.05), in the group calves comparing with the group of cows in all examined tissues (in ovaries as well as in uterus). It could be correlated with dynamic metabolism in immature calves which may led to increased production of ROS and on the other hand unsufficient antioxidant protection and lower level of estrogens which are known of their antioxidant properties. Obtain results could also indicate some connection between the regulation of steroidogenesis and the activity of antioxidative / oxidative system. The changes in SOD activity in ovaries and in uterus detected in present study seem to be sex steroid dependent. Due to the fact that the concentrations of steroid hormones are altered during ageing as well as reproductive development the differences between animals before and after sexual maturity are also expected. However, the mechanism of SOD involvement and the level of its hormonal regulation require further evaluation.