hCG-induced changes in LH/CG receptor mRNA transcript levels in the testis of adult hypophysectomized, ethane dimethyl sulphonate-treated rats.
To elucidate the molecular mechanisms involved in the development of precursor cells into functional Leydig cells, effects of hCG on the expression of the luteinizing hormone (LH)/chorionic gonadotrophin (CG) receptor gene were investigated in the testis of adult hypophysectomized, ethane dimethyl sulphonate (EDS)-treated rats. The alkylating drug EDS specifically destroys Leydig cells in the adult rat testis. In hypophysectomized rats, in the absence of LH, this is not followed by the formation of new Leydig cells, leaving a testis in which Leydig cell precursors are presumed to be the only cell type that possess LH receptors. The absence of Leydig cells was confirmed by determining the gene expression of two key steroidogenic enzymes, 3 beta-hydroxysteroid dehydrogenase/isomerase (3 beta HSD) and P-450 17 alpha-hydroxylase/C17-20 lyase (P-45017 alpha) in these animals. Northern blot analysis revealed that hypophysectomy, followed by EDS treatment decreased the total amount of LH/CG receptor mRNA and drastically changed the pattern of LH/CG receptor mRNA transcripts. In the testis of intact adult rats, the expression of the LH/CG receptor gene results in multiple mRNA transcripts with molecular sizes of approximately 7.0, 4.2, 2.5, 1.8 and 1.2 kb. The most abundant species observed in the testis of adult hypophysectomized, EDS-treated rats was the 1.8 kb mRNA transcript, whereas the levels of the other mRNA transcripts were decreased. To stimulate the development of precursor cells into functional Leydig cells, hypophysectomized, EDS-treated rats were treated with high doses of hCG (100 IU) for different periods of time.(ABSTRACT TRUNCATED AT 250 WORDS)
Veldhuizen-Tsoerkan
M B
MB
Department of Cell Biology and Histology, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
Ivell
R
R
Teerds
K J
KJ
D015096:3-Hydroxysteroid Dehydrogenases / Q000235:genetics; D000818:Animals; D015152:Blotting, Northern; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D007016:Hypophysectomy; D008297:Male; D008698:Mesylates / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D011974:Receptors, LH / Q000235:genetics*; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics; D013737:Testis / Q000187:drug effects / Q000378:metabolism*
D006063:Chorionic Gonadotropin; D008698:Mesylates; D012333:RNA, Messenger; D011974:Receptors, LH; D015096:3-Hydroxysteroid Dehydrogenases; D013254:Steroid 17-alpha-Hydroxylase; C002994:ethylene dimethanesulfonate