Immunohistochemical investigation of cannabinoid receptor 1 and 2 in intrauterine growth retardation (IUGR), placenta previa and preeclamsia

Aim:Tto investigate effect of endocannabinoid receptors on placental development that stimulate activation of intracellular signaling pathways in normotensive, preeclampsia, placenta previa and IUGR placentas. Materials and Methods: A total of 40 placentas(10 preeclampsia, 10 placenta previa, 10 IUGR and 10 normal placentas)were subjected to routine histological tissue protocol. Hematoxylin-Eosin andcannabinoid receptor 1/2immunohistochemical staining were performed. Preparations were evaluated and micrographed under light microscopy. Results: Fibrinoid tissue, vascular dilatation and congestion, hyalinization, degeneration and vacuolar structures were observed in tertiary villi structures of preeclampsia, placenta previa and IUGR placentas. Apoptotic appearance, pycnosis and hypertrophy were observed in cytotrophoblasts and syncytiotrophoblasts. In preeclampsia, CB1 reaction was observed in decidual nuclei and cytotrophoblasts of some tertiary villi. CB2 expression was moderately positive in decidualcytoplasm, but negative in cytotrophoblasts of root villi.Mild CB1 expression was observed in cytotrophoblasts of stem villi and tertiary villi in placenta previa group, butmainly negative in cytotrophoblasts. CB1 expression was positive in some vascular endothelial cells and syncytial nodes. CB2 was positively expressed in the nucleus and cytoplasm of decidual and endothelial cells of some small vessels.Mild CB1 expression was detected in some syncytial nodes inmaternal root villi in IUGR placentaand in mononuclear cells especially around hemorrhagic areas. CB1 expression was generally negative in syncytiotrophoblast cells. Conclusion:Development of decidual cells in preeclampsia, placenta previa and IUGR causedtrophoblastic invasion, increased syncytial nodes and apoptotisand degenerative process. Therefore, this situation depends on CB1 and CB2 receptors presence. Key Words:Placenta, preeclampsia, previa, cannabinoid receptor, intrauterine growth retardation