| First Author | Villalpando I | Year | 2003 |
| Journal | J Steroid Biochem Mol Biol | Volume | 86 |
| Issue | 2 | Pages | 151-8 |
| PubMed ID | 14568566 | Mgi Jnum | J:86408 |
| Mgi Id | MGI:2679781 | Doi | 10.1016/s0960-0760(03)00265-6 |
| Citation | Villalpando I, et al. (2003) Insulin-like growth factor I (IGF-I) regulates endocrine activity of the embryonic testis in the mouse. J Steroid Biochem Mol Biol 86(2):151-8 |
| abstractText | Insulin-like growth factor I (IGF-I) is important for gonadal and reproductive functions in mammals, although the physiological role of this growth factor during gonadal development in rodents remains largely unknown. Here, we examined the steady-state levels of IGF-I mRNA by the reverse transcriptase polymerase chain reaction (RT-PCR). IGF-I protein expression was also detected by Western blot. The effect of IGF-I as promoter of 17alpha-hydroxylase/C17-20 lyase and 17beta-hydroxysteroid dehydrogenase enzyme activity in vitro was evaluated by radioimmunoassay. Onset of IGF-I gene expression was on day E10 (urogenital ridge stage). IGF-I mRNA expression was markedly reduced on days E12 and E13 (testicular differentiation stage). IGF-I transcripts increased on day E14 and their transcription levels were maintained throughout the stages analyzed. Several IGF-I protein bands of 31-100 kDa were observed. Culture experiments demonstrated that 17alpha-hydroxyprogesterone and testosterone (T) secretion levels increased in the presence of IGF-I on days E11-E17. Additive effects of IGF-I plus (Bu)2cAMP were also seen during testicular development. It is proposed that IGF-I regulates the expression of key steroidogenic enzymes important for endocrine activity of the testis during prenatal development leading to establishment of the male phenotype and fertility. |
