IMMUNOHISTOLOGICAL DETECTION OF ANDROGEN RECEPTOR IN BOVINE PLACENTOMES DURING EARLY PREGNANCY

Abstract

A study was conducted at Veterinary Clinic for Obstetrics, Gynecology and Andrology, Justus-Liebig-University, Giessen, Germany during the year 2009- 10. In this study expression of androgen receptor (AR) in bovine placentomes during early pregnancy was investigated to identify the putative target cells (PTC) of placental androgens. For this purpose placentomes were collected from six healthy cows between 50 to 150 days of gestation at a local slaughter house of Giessen, Germany. These placentomes were assigned to two observational groups i.e. first and second trimester. An indirect immune peroxidase staining method was employed using the streptavidine biotin technique for signal enhancement following standard using a polyclonal primary antibody raised in rabbits against a peptide mapping at the N-terminus of the human AR was applied. Epididymal caput from a postpubertal bull was used as a positive control tissue. In bovine placentomes, irrespective from gestational age distinct to intense nuclear staining was observed in all invasive trophoblast giant cells located in the caruncular epithelium. Significant immune staining was also found throughout gestation in mature trophoblast giant cells (TGC) situated in the chorionic epithelium. This staining pattern suggests that AR expression is up-regulated during TGC differentiation. In bovine trophoblast cells the androgens and AR may be elements of an intracrine mechanism involved in the control of TGC differentiation and AR may be up-regulated by increasing androgen levels in differentiating trophoblast cells.