Ca2+ release from intracellular stores of pig oocytes at different stages of growth

摘要

Ca2+ release from intracellular stores of pig oocytes was investigated using the Ca2+-sensitive fluorescent dye chlorotetracycline. Oocytes were divided into growing ones and those that completed their growth using brilliant cresyl blue (BCB) staining. The stained oocytes (BCB "+") were determined as the ones that completed their growth, while the stainless ones (BCB "-aEuroe) were determined as those in the final stages of growth. In the BCB "+" and BCB "-aEuroe oocytes, prolactin, theophylline, GTP, and GDP cause Ca2+ to exit intracellular stores. In the oocytes that completed their growth, joint action of prolactin and GTP activates additional release of Ca2+, in which protein kinase C takes part. In growing oocytes, joint action of prolactin and GTP does not lead to additional release of Ca2(+). Joint action of theophylline and GDP in growing oocytes and oocytes that completed the growth stage promotes additional Ca2+ exit from intracellular stores. This exit is regulated by protein kinase A. The obtained data show that there various routes of Ca2+ release from intracellular stores in growing and grown pig oocytes.