Investigation of the Presence of Stem Cells in Rat Uterus Tissue in Postnatal Development Periods

Uterine tissue is an organ with a high proliferation capacity where regeneration, differentiation and shedding are seen. Although this tissue is regenerated every month, the source of it hasn’t been determined yet. Studies are carried out on stem cells being a source that can provide regeneration of the endometrium and the markers expressed by these cells. The purpose of this study was to examine the immunreactivity of CD9 and CD13 expressed by essential population of uterus and CD34, marker of hematopoietic stem cells, at various stages of the postnatal developing pro- cess. In this study, was used 42 female Wistar-albino rats split into six groups; Group I; newborn (2-days), Group II; pubertal (38-days), and Group III: fertile group (12 weeks), by identifying the stages of the estrous cycle in rats a) pro- estrus, b) estrus, c) metestrus, d) diestrus. The expression of CD9, CD13, and CD34 in uterine tissues excised from rats was investigated. In the groups of 38-days and 12-weeks, CD34-expressing cells were present in the stroma of the endometrium next to the myometrium, but such cells were absent in the 2-days group. All groups' uterine epithelium displayed CD9 expression, except for group 2-days. Endometrial stromal cells that expressed CD13 showed only little immureactivity in groups 2 and 38-days, while CD13 expression is noticeable in group 12-weeks. It was thought that the uterine endometrium could be regenerated in puberty and adulthood with the contribution of bone marrow-derived stem cells and uterine-derived epithelial and stromal cells.