Hormonal regulation of expression of tissue type plasminogen activator and plasminogen activator inhibitor type 1 in cultured rat granulosa cells.
In the present study, gonadotropin and gonadotropin-releasing hormone (GnRH) regulation of tPA and PAI-1 expression in PMSG-primed granulosa cells has been investigated. (i) Addition of gonadotropins (FSH and LH) and GnRH agonist (GnRHa) or PMA to the culture increases tPA activity; FSH (or LH) plus GnRHa (or PMA) in the culture further enhances the enzyme production to such an extent that a more obvious effect than the additive effect caused by these hormones used alone has been observed; (ii) in contrast, FSH and LH decrease PAI-1 activity, whereas GnRHa and PMA alone markedly increase PAI-1 mRNA level and PAI-1 activity. Because FSH and LH stimulate tPA production and have no significant effect on PAI-1 mRNA induction, the observed inhibition of PAI-1 activity by gonadotropins may be due to the occurrence of neutralization of PA and PAI-1 proteins in the conditioned media by the formation of complexes between PA and PAI-1; (iii) increases in PAI-1 mRNA level and activity by GnRH and PMA are completely inhibited by the co-addition of FSH or LH to the culture. It is, therefore, suggested that the mechanism of gonadotropin and GnRHa regulation of tPA and PAI-1 expression in granulosa cells is different.
Liu
Y X
YX
State Key Laboratory of Reproductive Biology, Academia Sinica, Beijing, PRC.
Peng
X R
XR
Liu
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Ny
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D000818:Animals; D002478:Cells, Cultured; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D006107:Granulosa Cells / Q000201:enzymology*; D007986:Luteinizing Hormone / Q000494:pharmacology; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D010959:Tissue Plasminogen Activator / Q000378:metabolism*
D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D010959:Tissue Plasminogen Activator