ABSTRACT
Insulin-like factor 3 belongs to the insulin superfamily relaxin subfamily.Insulin-like factor 3 is the main product secretion of leydig cells,and its synthetic process totally relies on the state of leydig cells differentiation.Insulin-like factor 3 plays an important role in testicular descent,and has a great clinical value for evaluating function of leydig cells.Meanwhile,insulin-like factor 3 is deemed to play an important role in germ cell survival and regulation of bone metabolism.
ABSTRACT
Immunoprecipitation and Western-blot were performed to detect the expression of LGR8 in the testes in wild type (Wt) and Insl3-knockout ( KO ) mice.Testis were harvested from WT and KO mice on embryonic day 18 (E18) and on postnatal(P) 1,3,7,14,17,20,23,51,and 90 days.LGR8 staining in Leydig cells was stronger in all Wt mice than that in KO mice( all P＜0.05 ).LGR8 expression on spermatocytes varies with age.Strong stain on P1 Wt and postpubertal mice was concentrated in the developing and mature acrosome of spermatids
ABSTRACT
Objective To observe the effects of estradiol benzoate (E_2),human cberionic gonadotropin (hCG) and luteinizing hormone-releasing hormone (LHRH) on testicular descent and their relation to the expression of insulin-like factor-3 (INSL3) mBNA in rats.Methods At birth,40 SD male rats were assigned to 4 groups,and each group consisted of 10 rats.Each group received injection of one of the following drugs:normal saline(NS),E_3,hCG+E_2,and LHRH+E_2 for 29 clays after birth.Total RNA was extracted from the testis on day 30 after birth.INSL3 was synthesized and further amplified by RT-PCR.Results (1) Testicular descent rate on clay 30 after birth was 100% (20/20) in the group of NS,0% (0/20) in the group of E_2,85% (17/20) of hCG + E_2,and 70% (14/20) of LHBH + E_2.There was no significant difference between the last two groups ( P = 0.45).(2) Weight of testis differed significantly among the groups ( F = 56.67,P＜0.01 ),being lightest in the group of E_2.(3) E_2 could damage the germ cells of testis,however hCG and LHRH ameliorated this situation. (4) The expression of INSL3 mBNA was absent in the group of E_2,while the other groups showed normal expression.Conclusion E_2 inhibits testicular descent in rats,while hCG and LHRH promote the progress.The mechanism seems to be related to the expression of INSL3 mRNA.