Changes in superoxide dismutase activity and estradiol-17 beta content in follicles of different sizes from ruminants

Subcellular distribution of oxygen free radical scavenging enzymes has recently been demonstrated in goat ovary. In the present study the follicles of the follicular phase were isolated mechanically from goat and sheep ovaries and grouped as small (< 3 mm), medium (3-6 mm) and large (> 6 mm) follicles. The specific (units/mg protein) and total (units/g tissue) activity of superoxide dismutase (SOD) was estimated in homogenate of different sizes of follicles. The small follicles of both the species contained highest specific and total activity (6.99 +/- 1.49, 107.9 +/- 3.1 in sheep and 3.57 +/- 0.09, 76.5 +/- 4.0 in goat, respectively), whereas large follicles showed lowest specific and total activity (32.02 +/- 0.25, 80.4 +/- 5.5 in sheep and 1.71 +/- 0.06, 63.20 +/- 2.20 in goat, respectively). The estradiol-17 beta was also estimated and expressed as ng/follicle. The results show that estradiol-17 beta content was highest in large follicle (8.00 +/- 0.46 in sheep and 4.5 +/- 0.73 in goat). The content of estradiol-17 beta was increased progessively as the size of the follicles increased. From these findings, an inverse relationship was observed between SOD activity and estradiol-17 beta content in the follicles of different sizes from ruminants which may have functional role in follicle development and steroidogenesis.