STIMULATION OF RATS FETUSES GROWTH BY TRANSPLANTATION OF RATS BONE MARROW CELLS OR HUMAN UMBILICAL CORD BLOOD CELLS DURING GASTRULATION

Background & Aim In humans and animals with interstitial transplantation and hemochorial type of the placenta decidual cells (DC) differentiates in the uterus, and form the maternal part of the placenta. In the absence of DC development stops at the stage of merosome. Previously, we have shown that non-pregnant rats bone marrow cells transplantation (BMT) stimulates the development of DC in pseudo-pregnant rats. It is of interest to study the effect of pregnant rats bone-marrow cells on fetal development during transplantation in the early stages of pregnancy, as well as whether human umbilical cord blood cells have a similar effect. Methods, Results & Conclusion Bone marrow mononuclear cells (BMMC) of 4-13 days of pregnancy rats were administered intravenously to does of the same gestation period. The weight and morphology of the fetuses were evaluated on the 18th day of pregnancy. It was found that BMMC transplantation on 7-9 days of pregnancy significantly increased the weight of fetuses to 835 ± 15 mg compared to the weight of non-pregnant does (745 ± 11 mg) and the weight of does fetuses, which were administered BMMC of diestrus does (772 ± 9 m). Administration of BMMC on 11-12 days of pregnancy reduced fetal weight to 587 ± 5 mg. Also the umbilical cord blood mononuclear cells (UCBMC) was used in the study, which were administered subcutaneously in doses of 26 or 71 × 106 cells per 250 g of animal weight. Fetal weight on the 18th day of pregnancy was the maximum (856 ± 8 mg) with the administration of UCBMC on the 9th day of pregnancy. With the administration of UCBMC on day 11 of pregnancy fetal weight was reduced to 803 ± 19 mg. The dose reduction of the UCBMC to 26 × 106 resulted in the weight of the fetus on the 9th day of pregnancy decrease to 813 ± 17 mg. Thus, both rats BMMC and a human UCBMC stimulate 18th day of pregnancy fetus weight after administration to the female rats on the 7th, 8th and 9th days of pregnancy in the period of gastrulation. No morphological abnormalities were found in the fetuses. There is also no increase in post-implantation death, which indicates that the increase in fetal weight is not the result of compensatory growth. Similar results of transplantation of different types of cells indicate a general mechanism of fetal growth stimulation. It is possible that the result develops due to stimulation of decidual cell function but particular mechanisms of it are still need future researches.