Meiotic resumption in response to luteinizing hormone is independent of a G(i) family G protein or calcium in the mouse oocyte

作者：Mehlmann Lisa M; Kalinowski Rebecca R; Ross Lavinia F; Parlow Albert F; Hewlett Erik L; Jaffe Laurinda A^*

来源：Developmental Biology, 2006, 299(2): 345-355.

DOI：10.1016/j.ydbio.2006.07.039

• meiotic resumption
• oocyte maturation
• luteinizing hormone
• heterotrimeric G proteins
• intracellular calcium
• follicle-enclosed oocytes
• mouse

The signaling pathway by which luteinizing hormone (LH) acts on the somatic cells of vertebrate ovarian follicles to stimulate meiotic resumption in the oocyte requires a decrease in cAMP in the oocyte, but how cAMP is decreased is unknown. Activation of G(i) family G proteins can lower cAMP by inhibiting adenylate cyclase or stimulating a cyclic nucleotide phosphodiesterase, but we show here that inhibition of this class of G proteins by injection of pertussis toxin into follicle-enclosed mouse oocytes does not prevent meiotic resumption in response to LH. Likewise, elevation of Ca2+ can lower cAMP through its action on Ca2+-sensitive adenylate cyclases or phosphodiesterases, but inhibition of a Ca2+ rise by injection of EGTA into follicle-enclosed mouse oocytes does not inhibit the LH response. Thus, neither of these well-known mechanisms of cAMP regulation can account for LH signaling to the oocyte in the mouse ovary.

• 出版日期2006-11-15