For example, since steroidogenesis is dependent on the cy-toskeleton, actin degradation during apoptosis could account for the rapid loss of steroidogenesis associated with luteal regression. Functional regression of the bovine CL occurs before the onset of measurable DNA degradation, which coincides with structural luteolysis, but it is not clear whether this is the case in other species. In addition, since caspase activity precedes DNA ladders during apoptosis, it might be of interest to reevaluate the occurrence of apoptosis (based on protease activity) relative to the functional regression of the CL. buy levaquin online
Theca cells displayed intense positive staining for caspase-3 in healthy and TUNEL-positive follicles. The role of caspase-3 in rat ovarian theca cells is not clear, since this cell type does not typically undergo apoptosis. Ultrastructural studies in our laboratory have demonstrated that theca cells accumulated large lipid droplets but did not display nuclear fragmentation or DNA degradation during anti-eCG antiserum-induced follicular atresia. We have also demonstrated that theca cells do not contain endogenous DNase I. It is possible that caspase-3 is activated in theca cells but does not lead to apoptosis because these cells lack the endogenous DNase I necessary to complete the apoptotic program. Interestingly, sterol regulatory element binding protein (SREBP) has recently been identified as a substrate of caspase-3.