Early Pregnancy(3)

The mammalian endometrium is a complex and dynamic tissue. It is unique in that it is one of the only tissues to undergo cyclic changes and regular regeneration in the adult human, and as such is of great interest to those studying processes of tissue remodeling. The dramatic changes occurring in the stromal cells of the endometrium during the later stages of each secretory phase, which are magnified and continued during the initiation of pregnancy under the influence of the steroid hormones, involve a significant degree of fundamental change to the cell. Ubiquitin is secreted from human term decidual cells in culture. It is possible, therefore, that the ubiquitin system could be involved in the extensive uterine remodeling during the menstrual cycle and pregnancy. Recent work by Hansen and coworkers has shown that UCRP is one of the proteins secreted by the bovine uterus in response to type 1 interferons. The bovine conceptus produces IFN-t during the first 30 days of pregnancy prior to placental attachment, during which time it is thought to maintain the pregnant state. In the early stages of pregnancy, bovine UCRP was found to be secreted by the endometrium, at times coincident with maximal IFN-t production by the conceptus, and UCRP mRNA in bovine endometrium is up-regulated by IFN-t. ampicillin antibiotic

In this paper we report the presence of ubiquitin and UCRP in the human and baboon endometrium. Changes in levels and distribution of these proteins in the endometrium during the menstrual cycle and pregnancy may provide clues as to their possible specialized roles in this organ.