Progesterone dependent uptake of uteroglobin by rabbit endometrium

Abstract

Unlabeled or 3H-labeled UGL, isolated from rabbit lungs, was injected intraluminally into the uteri of ovariectomized low dose progesterone substituted and unsubstituted animals as well as into mated animals on the fifth day of pregnancy. It was offered to the endometrium, in this last case, in competition with endogenously synthesized UGL. 3H-labeled IgG served as a control. The animals were killed 24 h after the experiment. Immunohistograms and autoradiograms showed that UGL was taken up by the whole endometrium of the ovariectomized animals but only when progesterone was present. In the preimplantation uterus, uptake was limited to clusters of smaller cells accumulated in the lumen adjacent to the epithelium, whereas IgG remained within the uterine lumen, forming a dense layer on the endometrial surface.

A Two-receptor Pathway for Catabolism of Clara Cell Secretory Protein in the Kidney

“…Besides the kidney, tissues with confirmed coexpression of megalin and cubilin are the yolk sac and the distal ileum (31). The cellular uptake of CCSP has been described in the renal proximal tubules and in the endometrium (13,41,42). It remains to be shown whether megalin and cubilin are coexpressed in the endometrium or whether CCSP is taken up in other tissues expressing both receptors.…”

Uteroglobin, an apically secreted protein of the uterine epithelium, is secreted non‐polarized from MDCK cells and mainly basolaterally from Caco‐2 cell

“…The media from transfected MDCK cells (Fig. 1, lane 1) and Caco-2 cells (lane 3) contained uteroglobin whereas the media from non- It has been reported that uteroglobin in the presence of progesterone is taken up by the endometrium [28]. The possibility that also MDCK cells take up uteroglobin possibly followed by transcytosis was therefore investigated.…”