Developmental expression of Ca++/Mg++-dependent endonuclease activity in rat granulosa and luteal cells.

Abstract A Ca++/Mg++-sensitive endonuclease has been associated with programmed cell death in a variety of endocrine and nonendocrine dependent tissues. In view of the remarkable similarity of the process of the regression of the corpus luteum and other models ofprogrammed cell death, we studied the occurrence of this endonuclease activity in granulosa cells at different developmental states and thecorpus luteum. Our results show that while undifferentiated granulosa cells do not express this endonuclease activity, treatment withpregnant mares serum gonadotropin results in a rapid increase in endonuclease activity that is maintained following ovulation and luteinization of granulosa cells.