Archive for the ‘Gonadotropin’ Category

Transcripts of the PACAP gene have been detected by in situ and Northern hybridizations in adult testes , and by immunocytochemistry PACAP immunoreactiv-ity has been found in spermatogonia and primary spermatocytes, but not in mature spermatids or spermatozoa , or in Sertoli and Leydig cells . These findings suggest that PACAP may function as a […]

We examined the effects on fetal testicular steroidogenesis of selected growth and paracrine factors, including ac-tivin, inhibin, EGF, IGF-1, IFG II, NGF, BDNF, VIP, and PACAP-27. They had no effect on fetal testicular steroidogenesis, except for VIP and PACAP-27. These peptides stimulated fetal testicular steroidogenesis very significantly, but, interestingly, no effects were found on BLT-1 […]

Two human mutations have also been reported supporting the contention that fetal testicular steroidogenesis must begin independent of any pituitary LH. A mutation in the LH receptor produces pseudohermaphroditism, with testes and normal wolffian duct derivatives, but few germ cells. This phenotype is consistent with the contention that the testosterone necessary for wolffian duct stabilization […]

LH was detectable initially in the fetal pituitary gland on E16.5, and in the fetal plasma at very low levels (< 0.005 (xg/L) on E17.5. The first significant increase in this level was delayed until E20.5, which corresponds to the age when the pituitary LH has been found to start stimulating fetal Leydig cell steroidogenesis in […]

An interesting finding was that basal testosterone production increased significantly only in incubations with intact testes (Fig. 3), whereas no, or only a marginal, increase in basal testosterone was found during hours 1-5 of incubation with dispersed testicular cells (Fig. 4). We found that recombinant rat LH at a low concentration of 0.005 (jug/L (2.5- […]

Testicular Testosterone Testicular testosterone content was measured between Days E15.5 and E21.5 (Fig. 1). It was 12.0 ± 2.0 pg/testis on E15.5 and increased on E16.5, E17.5, and E18.5 slightly to 32.2 ± 5.0, 45.6 ± 7.6, and 61.1 ± 6.9 pg/testis, respectively. A sharp and significant increase occurred between E18.5 and E19.5, to 126 […]

Pituitary and Plasma LH in Male Fetal Rats Fetal pituitary LH was undetectable on E15.5, whereas it was 3.25 pg/gland on El6.5 and increased thereafter significantly with fetal age (Fig. 1). The fetal plasma concentration of LH was very low on E17.5 (0.005 ± 0.001 |xg/ L), and it increased marginally on El8.5 and El9.5. […]