Page 30 - N. Metabolism and metabolic diseases

[N. Metabolism and metabolic diseases-16]

Oxytocin-associated signaling is related with steroidogenesis

and differentiation of placenta

Sung-Min An¹, Min Jae Kim¹, Da Som Kim¹, So Young Kim¹, Da Hee Kang¹, Seung Chul Kim², Beum-Soo An¹˙*

¹Department of Biomaterials Science, College of Natural Resources & Life Science/Life and Industry Convergence

Research Institute, Pusan , Miryang KS011, Korea, ²2Department of Obstetrics and Gynecology, Biomedical
Research Institute, Pusan National University School of Medicine, Pusan KS012, Korea

Oxytocin (OXT) plays a significant role during pregnancy, especially at the end of pregnancy. Some studies reported

that OXT is involved in stimulation of steroidogenesis in several organs. However, the effects of OXT on placental

steroidogenesis have not been established. In this study, we studied the regulation of steroid hormones and
steroidogenic enzymes by OXT-associated signaling in vitro and in vivo. OXT increased gene expression of
steroidogenic enzymes, which converts pregnenolone (PG) to progesterone (P4) and dehydroepiandrosterone (DHEA)

in vitro. In OXT administrated pregnant rat, PG and DHEA levels were significantly increased in the serum and
expression of enzymes synthesizing DHEA, testosterone (T) and estrogen (E2) was increased in placenta tissues.

Furthermore, OXT was found to affect placental cell differentiation, closely related with steroid hormone synthesis.
After treatment of atosiban, the antagonist of OXT receptor to the pregnant rats, the concentration of E2 was

decreased in the serum and the expression of E2-synthesizing enzyme was also reduced. Our findings suggest that
OXT regulates the expression of steroidogenic enzymes in the placenta and production of critical steroid hormones

during pregnancy and finally contributes the maintenance of pregnancy.