Comparative Studies on the In Vitro: RESULTS(1)
Expression of aSMA
During the luteal phase of the menstrual cycle, aSMA staining was absent in stromal fibroblasts of the baboon endometrium. Limited staining was evident in smooth muscle cells surrounding the arterioles and venules (Fig. 1A). Immunohistochemical localization of aSMA was evident in the stromal cells of the simulated-pregnant baboon endometrium (Fig. 1C) whereas in the pregnant animal, aSMA expression was much lower and almost undetectable as compared to that in the simulated-pregnant animal (Fig. 1E). buy antibiotics online
Stromal cells separated by enzymatic digestion from both human and baboon endometrium did not express the aSMA protein prior to plating (Fig. 2). However, when stromal cells were plated and grown in culture, aSMA was produced, suggesting that the culture conditions are sufficient to induce the expression of this protein. This occurred in both baboon (Fig. 2A) and human (Fig. 2B) stromal cells.
Decidualization of Baboon and Human Stromal Cells
In vivo, IGFBP-1 was absent in the stromal cells of cycling (Fig. 1B) and simulated-pregnant baboon endometrium (Fig. 1D). IGFBP-1 staining was apparent in endometrial stromal cells that had undergone decidualization at the trophoblast-maternal junction (Fig. 1F; arrow), suggesting that a conceptus factor is involved in inducing the expression of IGFBP-1 during decidualization in vivo.
FIG. 1. Immunocytochemical localization of aSMA and IGFBP-1 in the baboon endometrium. A) Alpha SMA and B) IGFBP-1—midluteal phase, Day 10 postovulation; C) aSMA and D) IGFBP-1—simulated-pregnant (Day 25 postovulation); E) aSMA and F) IGFBP-1—pregnant, implantation site, Day 29 postovulation. Note the induction of aSMA in response to hormones in the simulated-pregnant animal (C) and the decrease at the implantation site (E). IGFBP-1 is absent in stromal cells from cycling (B) and simulated-pregnant animals (D) and is induced at the implantation site in the pregnant animal (F; arrowed). cts, Cytotrophoblastic shell; dc, decidua; gl, glands; pl, placenta; se, surface epithelium. Magnification X143 (reproduced at 75%).