PLATFORM SESSION 8: REGULATION OF GONADOTROPINS AND THEIR RECEPTORS: I
Chair: Narayan, Prema1, 1
Co-chair: Rispoli, Louisa1, 1
4:30 PM-6:30 PM
(62) PLASMINOGEN ACTIVATORS, PLASMINOGEN ACTIVATOR INHIBITOR TYPE-1, STEROIDOGENIC ACUTE REGULATORY PROTEIN, LH, AND FSH RECEPTORS IN CORPUS LUTEUM OF RHESUS MONKEY.
Liu, Yi-Xun1, Feng, Qiang1, Liu, Kui1, Gao, Hong-Juan1, Fu, Guo-Qiang1, Hu, Zhao-Yuan1, Zou, Ru-Jin1, 1 State Key Laboratory of Reproductive Biology, Beijing, CN
ABSTRACT- Adult female rhesus monkeys were treated with PMSG and/or hCG to induce ovulation and luteinization. At various times of corpus luteum development, the ovaries were removed for in situ hybridization, immunocytochemistry and northern blot analysis. tPA mRNA and activity increased dramatically in the lueinized granulose cells just prior to ovulation, and in the luteal cells obtained on day13 when luteal progesterone production decreased to the lowest level, indicating the involvement of tPA in the precesses of ovulation and luteal regression. uPA, on the other hand, was low in the granulose cells before ovulation and in the corpus luteum at late stage during process of luteolysis, its activity in the corpus luteum sharply increased only at the early stage of luteinization just after ovulation, indicating that uPA may play a role in tissue remodeling and angiogenesis during the early stage of corpus luteum formation. Northern blot, in situ hybridization and fibrin-overlay analysis showed a coordinated expression of tPA and PAI-1 in the corpus luteum, such that the higher expression of tPA was correlated with the lower production of PAI-1 which reached the peak level in the tissue always before the tPA peak. Addition of monoclonal antibodies against tPA to the culture enhanced the basal and LH-induced luteal PAI-1 activity and progesterone production, indicating that increase in the tissue tPA activity may be directly related to luteal regression. Expression of both steroidogenic acute regulatory protein (StAR) mRNA and antigen increased in the corpus luteum which was correlated to the higher level of luteal progesterone from day 5 to 9 at the early stage of corpus luteum development , and the StAR expression decreased from Day13 thereafter, which was coincident with the decreasing level of the steroid synthesis. This finding plus our similar data in rat demonstrated previously suggest that StAR expression in the corpus luteum may be regarded as a reliable marker of luteal function in the primate. In situ hybridization also showed that the corpus luteum at late stage expressed FSH receptor. The role of FSH in the corpus luteum development, however, is unknown and needed to be further clearified.
KEY WORDS: Corpus Luteum, rhesus monkey, plasminogen activators, plasminogen activator inhibitor