LH reduces proliferative activity of cumulus cells and accelerates GVBD of porcine oocytes.
It has been reported that LH receptor (LHR) mRNA is not detected in cumulus cells of porcine cumulus-oocyte complexes (COCs) just after collection from small antral follicles. The present study showed that the formation of LHR in cumulus cells was up-regulated by the cultivation with 20 ng/ml FSH. When the newly synthesized receptors were stimulated by 1.0 microg/ml LH, significantly higher levels of cAMP and progesterone production in cumulus cells were observed as compared with those of COCs cultured with FSH. A loss of proliferative activity of cumulus cells was induced by the additional LH to FSH-containing medium; however, the inhibitory effect was overcome by progesterone receptor antagonist RU486. Furthermore, the addition of LH also accelerated ongoing GVBD in cumulus cells-enclosed oocytes. These results revealed that during in vitro meiotic maturation of porcine COCs, progesterone secreted by FSH- and LH-stimulated cumulus cells reduced proliferative activity of cumulus cells; the changes of cumulus cells might be involved in inducing meiotic resumption of porcine oocytes.
Okazaki
Tetsuji
T
Laboratory of Animal Reproduction, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8528, Japan.
Nishibori
Masahide
M
Yamashita
Yasuhisa
Y
Shimada
Masayuki
M
D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division; D000242:Cyclic AMP; D004305:Dose-Response Relationship, Drug; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000235:genetics / Q000494:pharmacology*; D008186:Luteolytic Agents / Q000494:pharmacology; D008540:Meiosis; D009865:Oocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D006080:Ovarian Follicle / Q000166:cytology*; D011374:Progesterone / Q000032:analysis; D011974:Receptors, LH / Q000096:biosynthesis / Q000235:genetics; D013552:Swine; D013997:Time Factors; D015854:Up-Regulation
D008186:Luteolytic Agents; D011974:Receptors, LH; D011374:Progesterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D000242:Cyclic AMP