{'fraction_non_alphanumeric': 0.01641949152542373, 'fraction_numerical': 0.0, 'mean_word_length': 5.491408934707904, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Progesterone secretion by apoptotic granulosa cells: A novel characteristic mediated by decreased intracellular potassium levels

During the cyclic process of folliculogenesis in the mammalian ovary, a cohort of follicles develop towards the pre-ovulatory stage, although only one follicle eventually releases a mature oocyte. This selected follicle is known as the dominant, or Graafian, follicle. The rest of the developing follicles undergo a degenerative process called atresia, which is characterized by apoptosis of the cells (in particular, the granulosa cells) within the dying follicle. The cells of an atretic follicle exhibit the many features of apoptosis such as activation of caspases, degradation of the genome, loss of cell volume and loss of intracellular potassium. The loss of intracellular potassium is a contributing factor to several apoptotic events such as the activation of caspases and apoptotic nucleases. Interestingly, atretic follicles also produce augmented levels of progesterone with a subsequent decline in estrogen production. This seems to be an important feature during atresia, for granulosa cells go to great lengths to preserve the steroidogenic machinery as the cell dies. To investigate the possible role intracellular potassium plays in the steroidogenic shift; non-apoptotic cells with lowered potassium levels were prepared by exploiting the cell's ability to regulate its volume in response to a hypotonic insult. These cells were found to greatly augment their production of progesterone, suggesting the change in steroidogenesis by the cells of an atretic follicle is directly correlated to the concentration of intracellular potassium and is not simply a by-product of apoptosis. This article will focus on the plausibility of a K + -dependent mechanism for enhancing the production of progesterone by dying granulosa cells during atresia.