Proteolytic and antiproteolytic activities in goat antral follicles

Abstract Goat antral follicles were dissected and classified initially by size into three groups: 6 mm. Follicles less than 3 mm diameter were studied without any further classification. All others were classified according to their gross stereoscopic microscope appearance into four sub-groups. Histological observation showed that sub-group 1 consisted mainly of non-atretic follicles, sub-group 2 of follicles in the early stages of atresia, while sub-groups 3a and 3b were formed by secondary and tertiary atretic follicles. Tryptic and anti-trypic activites were measured in follicular fluid, homogenized follicular cells and empty follicular sacs, using a fluorometric procedure. Antitryptic activity in follicular fluid was found to be directly correlated with progress of atresia and inversely with follicular growth, being smallest in big (>6 mm), non-atretic follicles and consistently higher in small ( 6 mm non-atretic follicles. High trypsin-like activity was found in the cell walls of non-atretic or early atretic follicles. This activity was significantly lower in sub-group 3a follicles and was almost absent in tertiary atretic follicles (sub-group 3b). In contrast, trypsin-like activity in granulosa cells recovered by centrifugation of follicular fluid was twice as high in sub-group 3a as in sub-groups 1 and 2 and almost five times higher than in sub-group 3b.