Biology of Reproduction, Vol 58, 520-525, Copyright © 1998 by Society for the Study of Reproduction

ARTICLES

Immunoexpression of the steroidogenic enzymes 3-beta hydroxysteroid dehydrogenase and 17 alpha-hydroxylase, C17,20 lyase and the receptor for luteinizing hormone (LH) in the fetal rat testis suggests that the onset of Leydig cell steroid production is independent of LH action

G Majdic, PT Saunders and KJ Teerds
MRC Reproductive Biology Unit, Edinburgh, United Kingdom.

The production of testosterone in the adult testis is mainly regulated by LH. Testosterone is essential for normal development of the male fetus. The regulation of testosterone production in the fetal testis is less clear than in the adult testis, and there are indications that at least the onset of androgen production in the fetal testis takes place in an LH-independent way. The aim of the present study was to compare the onset of synthesis and pattern of expression of LH receptors and two important steroidogenic enzymes, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and 17alpha-hydroxylase/17,20-lyase (P450c17), in fetal rat gonads. Whole fetuses (13.5 and 14.0 postcoitum (p.c.), testes, and ovaries dissected from fetuses on Days 14.5 p.c. to 20.5 p.c. and testes obtained on Days 3, 5, and 7 postpartum were fixed in Bouin's solution and processed for immunocytochemistry. In all samples of fetal testis, 3beta-HSD was detected on Day 14.5 p.c., and immunoexpression of P450c17 appeared one day later on Day 15.5 p.c. Thereafter, immunoexpression of both enzymes remained intense throughout gestation and postnatally. In contrast, immunoexpression of LH receptors was detectable only from Day 16.5, when a few weakly positive cells were present, but it became more intense one and two days later. Similar to the immunostaining for 3beta-HSD and P450c17, immunostaining for LH receptor remained strong throughout gestation and during the first 7 days of postnatal life. No immunoexpression of any of the three proteins studied was detected in the fetal ovary at any age. These data show very early immunoexpression of 3beta-HSD, which was detected one day before the reported start of steroid production by the fetal Leydig cells. In contrast, immunoexpression of LH receptors was evident only after immunoexpression of both the steroidogenic enzymes studied had became apparent and after the reported start of steroidogenesis, which is consistent with the theory that onset of steroidogenesis in the fetal rat testis is an LH-independent process.

This article has been cited by other articles:

				P J O'Shaughnessy, I D Morris, and P J Baker Leydig cell re-generation and expression of cell signaling molecules in the germ cell-free testis Reproduction, June 1, 2008; 135(6): 851 - 858. [Abstract] [Full Text] [PDF]

				K. J Teerds, E. Rijntjes, M. B Veldhuizen-Tsoerkan, F. F G Rommerts, and M. de Boer-Brouwer The development of rat Leydig cell progenitors in vitro: how essential is luteinising hormone? J. Endocrinol., September 1, 2007; 194(3): 579 - 593. [Abstract] [Full Text] [PDF]

				R. C. Bott, R. M. McFee, D. T. Clopton, C. Toombs, and A. S. Cupp Vascular Endothelial Growth Factor and Kinase Domain Region Receptor Are Involved in Both Seminiferous Cord Formation and Vascular Development During Testis Morphogenesis in the Rat Biol Reprod, July 1, 2006; 75(1): 56 - 67. [Abstract] [Full Text] [PDF]

				J. Simard, M.-L. Ricketts, S. Gingras, P. Soucy, F. A. Feltus, and M. H. Melner Molecular Biology of the 3{beta}-Hydroxysteroid Dehydrogenase/{Delta}5-{Delta}4 Isomerase Gene Family Endocr. Rev., June 1, 2005; 26(4): 525 - 582. [Abstract] [Full Text] [PDF]

				T. L. Gaskell, A. Esnal, L. L.L. Robinson, R. A. Anderson, and P. T.K. Saunders Immunohistochemical Profiling of Germ Cells Within the Human Fetal Testis: Identification of Three Subpopulations Biol Reprod, December 1, 2004; 71(6): 2012 - 2021. [Abstract] [Full Text] [PDF]

				S.M.L. Chamindrani Mendis-Handagama and H.B. Siril Ariyaratne Differentiation of the Adult Leydig Cell Population in the Postnatal Testis Biol Reprod, September 1, 2001; 65(3): 660 - 671. [Abstract] [Full Text] [PDF]

				L. L.L. Robinson, N. A. Sznajder, S. C. Riley, and R. A. Anderson Matrix metalloproteinases and tissue inhibitors of metalloproteinases in human fetal testis and ovary Mol. Hum. Reprod., July 1, 2001; 7(7): 641 - 648. [Abstract] [Full Text] [PDF]

				L. D. Quirke, J. L. Juengel, D. J. Tisdall, S. Lun, D. A. Heath, and K. P. McNatty Ontogeny of Steroidogenesis in the Fetal Sheep Gonad Biol Reprod, July 1, 2001; 65(1): 216 - 228. [Abstract] [Full Text] [PDF]

				H.B. Siril Ariyaratne, J. Ian Mason, and S.M.L. C. Mendis-Handagama Effects of Thyroid and Luteinizing Hormones on the Onset of Precursor Cell Differentiation into Leydig Progenitor Cells in the Prepubertal Rat Testis Biol Reprod, September 1, 2000; 63(3): 898 - 904. [Abstract] [Full Text]

				H.B.S. Ariyaratne, S.M.L.C. Mendis-Handagama, and J.I. Mason Effects of Tri-Iodothyronine on Testicular Interstitial Cells and Androgen Secretory Capacity of the Prepubertal Rat Biol Reprod, August 1, 2000; 63(2): 493 - 502. [Abstract] [Full Text]

				P. J. O'Shaughnessy, P. J. Baker, M. Heikkila, S. Vainio, and A. P. McMahon Localization of 17{beta}-Hydroxysteroid Dehydrogenase/17-Ketosteroid Reductase Isoform Expression in the Developing Mouse Testis--Androstenedione Is the Major Androgen Secreted by Fetal/Neonatal Leydig Cells Endocrinology, July 1, 2000; 141(7): 2631 - 2637. [Abstract] [Full Text] [PDF]

				H.B. Siril Ariyaratne, S.M.L. Chamindrani Mendis-Handagama, D. Buchanan Hales, and J. Ian Mason Studies on the Onset of Leydig Precursor Cell Differentiation in the Prepubertal Rat Testis Biol Reprod, July 1, 2000; 63(1): 165 - 171. [Abstract] [Full Text]

				M.A. Kaminski, C.J. Corbin, and A.J. Conley Development and Differentiation of the Interstitial and Tubular Compartments of Fetal Porcine Testes Biol Reprod, January 1, 1999; 60(1): 119 - 127. [Abstract] [Full Text]

				S.M.L.C. Mendis-Handagama, H.B.S. Ariyaratne, K.R. Teunissen van Manen, and R.L. Haupt Differentiation of Adult Leydig Cells in the Neonatal Rat Testis Is Arrested by Hypothyroidism Biol Reprod, August 1, 1998; 59(2): 351 - 357. [Abstract] [Full Text]