Figure 6. Bile acids act via CAR in the testis of Fxα−/− males.

(a) Testis weights in Fxrα−/− mice treated with vehicle or TCPOBOP (6 mg/kg) in conjunction with BA-diet for 2 weeks. (b) Sperm count in Fxrα−/− mice treated with vehicle (DMSO) or TCPOBOP (6 mg/kg) in conjunction with BA-diet for 2 weeks. (c) Apoptosis in Fxrα−/− mice treated with vehicle or TCPOBOP (6 mg/kg) in conjunction with BA-diet for 2 weeks (n = 5–7 per group) analyzed by TUNEL staining. For the quantification of TUNEL analyses, the number of tubules with TUNEL-positive cells is indicated as the number of positive tubes per 100 seminiferous tubules (n = 5–7). (d) Testicular mRNA accumulation of Cyp2b10 normalized to β-actin mRNA levels in Fxrα−/− mice treated with vehicle or TCPOBOP (6 mg/kg) in conjunction with BA-diet for 2 weeks (n = 5–7 per group). (e) Testis weights in C57Bl6J mice treated with vehicle or CAR-InAg for 2 weeks (n = 5–7 per group). (f) Sperm count in C57Bl6J mice treated with vehicle or CAR-InAg for 2 weeks (n = 5–7 per group). (g) Apoptosis in C57Bl6J mice treated with vehicle or CAR-InAg for 2 weeks analyzed by TUNEL staining. For the quantification of TUNEL analyses, the number of tubules with TUNEL-positive cells is indicated as the number of positive tubes per 100 seminiferous tubules (n = 5–7 per group). (h) Testicular mRNA accumulations of Shp, Stra8 and Cyp2b10 normalized to β-actin mRNA levels in C57Bl6 males treated 2 weeks with CAR-InAg (30 mg/kg/day) or vehicle (DMSO) (n = 5–7 per group). (i) mRNA expression of Shp and Cyp2b10 normalized to β-actin mRNA levels in GC1spg cell line treated 12 h or CAR-InAg (10⁻⁶ M) or vehicle (DMSO 1/1000). In all panels, data are expressed as means ± standard error of the mean. Statistical analysis: *P < 0.05.