Comparative Studies on the In Vitro: DISCUSSION(6)
Expression of mRNA of PKA subunits did not differ in nondecidualized and decidualized cells in either the baboon or the human. This confirms a recent study showing that all four isoforms were present in human endometrial stromal cells, with no difference in the mRNA expression of the isoforms between decidualized and nondecidualized cells. Even the mRNA for catalytic subunits did not change. In contrast, Knutsen et al. demonstrated that a mouse Sertoli cell line expressed the RIa, RIIa, and RIIp subunits and that RIIp was up-regulated by cAMP, reaching maximal levels after 12 h of stimulation. In primary cultures of rat Sertoli cells, mRNAs for RIa, RIIa, and RIIp are regulated with cAMP treatment whereas in the TM4 cell line, none of the various PKA subunit mRNAs were regulated by cAMP. In ovarian follicular cells, RIa protein levels increase while mRNA levels do not change in response to elevated cAMP levels. Thus, it appears that PKA regulatory subunits are differentially regulated depending on the cell type. buy ortho tri-cyclen
In summary, it is apparent that the decidualization processes in humans and baboons involve similar molecules and pathways. It is also evident from our studies that cAMP in conjunction with hormones augments this differentiation process. Given the limitations on studies with early-gestational tissues from women, the baboon provides a valuable model for studying cellular regulation during early pregnancy. As such, functional studies done in vitro can be extrapolated to an in vivo system. The establishment of an in vitro decidualization model in a nonhuman primate will enable us to elucidate the precise biochemical and molecular events associated with this critical process required for the establishment of pregnancy.