Fig. 5. Effect of natriuretic peptide receptor 2 (NPR2) knockdown on testosterone secretion in mouse Leydig cells. (A) The effects C-type natriuretic peptide (CNP) and human chorionic gonadotropin (hCG) on CNP/NPR2 expression. (B) Concentration of testosterone secretion in the culture medium transducted with shRNA-NPR2 lentivirus. (C) Relative mRNA expression of genes (Star, Cyp11a1, 3β-hydroxysteroid dehydrogenase [3β-HSD], insulin-like factor 3 [Insl3], and luteinizing hormone receptor [LHR]) in mouse Leydig cells transducted with shRNA-NPR2 lentivirus. (D) Relative protein expression of Star and Cyp11a1 in mouse Leydig cells transducted with shRNA-NPR2 lentivirus. The β-actin was used as internal control. The results are presented as the mean±standard error of mean and are representative of three independent experiments. Bars with different letters are significantly different (p<0.05).