Type I IGF receptors of Leydig cells are upregulated by human chorionic gonadotropin.
The effects of human chorionic gonadotropin (hCG) on type I insulin-like growth factor (IGF) receptors of purified Leydig cells were investigated. Sprague-Dawley rats (50 day-old) were treated with a single injection of hCG 10 units intraperitoneally, type I IGF receptors were then determined daily for 4 days. HCG caused a rapid increase in type I IGF receptors within 24 h, which returned to basal by 72 h. There was no significant change in binding affinity. Our present study indicates that type I IGF receptors of Leydig cells are up regulated by hCG, and this may be one mechanism by which hCG and IGF-I interact to enhance Leydig cell steroidogenesis.
D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007985:Leydig Cells / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011972:Receptor, Insulin / Q000187:drug effects* / Q000378:metabolism; D017451:Receptors, Somatomedin; D013002:Somatomedins / Q000378:metabolism*; D013268:Stimulation, Chemical
D006063:Chorionic Gonadotropin; D017451:Receptors, Somatomedin; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D011972:Receptor, Insulin