PMON251 Loss of Constitutive Androstane Receptor, CAR reduces the serum androgens levels and alters reproductive function

The nuclear receptor, Constitutive Androstane Receptor (CAR/NR1i3) is extensively known for its detoxification function in the liver. We have identified the role of CAR in regulating androgen levels and regulating testis function. Although the inactivation of CAR by the sex hormone axis via androstanol has been known for decades, its role in regulating reproduction has not been addressed. On examining the WT mice and the global CARKO mice, we found that CARKO mice have reduced serum testosterone and androstanol levels. Further, the levels of the steroidogenic gene, Srd5a1 was significantly reduced. This result correlated well with reduced anogenital distance in males, increased anxiety and subfertility. However, we did not find differences in the expression of detoxification genes in the CARKO testis. Histological analysis of the testis of the CARKO mice revealed abnormal Leydig cells and Oil Red O staining showed lipid accumulation in the Leydig cell island. We are currently examining the effect of the reduced androgens in the hypothalamic-pituitary-gonadal axis in the CARKO mice model. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.