Please use this identifier to cite or link to this item:
Title: Testicular 3β-hydroxysteroid dehydrogenase/Δ<sup>5-4</sup> isomerase in the hypophysectomized rat: Effect of treatment with 5α-dihydrotestosterone
Authors: Fanjul, L. F. 
Quintana Aguiar, José Martín 
Gonzalez, J.
Santana Delgado, María Del Pino 
Ruiz De Galarreta Hernandez,C. Manuel 
Estévez Rosas, Francisco Jesús 
UNESCO Clasification: 32 Ciencias médicas
320502 Endocrinología
Keywords: Corticotropin-Releasing Factor
Human Chorionic-Gonadotropin
Androgen Biosynthesis, et al
Issue Date: 1992
Journal: Journal of Endocrinology 
Abstract: The in-vivo regulatory effect of androgens on steroidogenesis was investigated. Adult (2 to 3 months old) hypophysectomized rats were treated intratesticularly with increasing doses of 5-alpha-dihydrotestosterone (DHT; 10-200-mu-g/100 g body weight) or vehicle (50-mu-l dimethyl sulphoxide; DMSO) in the contralateral testis. Intratesticular testosterone concentrations were extremely low in hypophysectomized rats 15-20 days after surgery. Treatment with DHT caused a dose-dependent inhibition of testicular 3-beta-hydroxysteroid dehydrogenase/DELTA-(5-4) isomerase (3-beta-HSD) 2 h later, and this effect was apparent at the dose of 20-mu-g/100 g body weight (P < 0.01). The inhibitory effect of 3-beta-HSD was not due to a possible interference of DHT in the enzyme assay, since various concentrations of the androgen (0.1-100-mu-mol/l) were ineffective as inhibitors of 3-beta-HSD. The highest dose of DHT used in this study (200-mu-g/100 g body weight) resulted in a rapid (1-2 h) and transient (4-6 h) inhibition (approximately 80%) of 3-beta-HSD activity. Pretreatment of rats with the antiandrogen cyproterone acetate (5 mg/rat) or the protein synthesis inhibitor cycloheximide (10 mg/rat) did not affect the enzyme activity of testes injected with DMSO, but counteracted the inhibitory effect of DHT on 3-beta-HSD activity in the contralateral testis. The results presented suggest that the inhibitory effect of the non-aromatizable androgen DHT is receptor-mediated and involves the synthesis of a factor(s) that modulates 3-beta-HSD activity.
ISSN: 0022-0795
DOI: 10.1677/joe.0.1330237
Source: Journal Of Endocrinology[ISSN 0022-0795],v. 133 (2), p. 237-243
Appears in Collections:Artículos
Show full item record


checked on Dec 3, 2023

Page view(s)

checked on Dec 2, 2023

Google ScholarTM




Export metadata

Items in accedaCRIS are protected by copyright, with all rights reserved, unless otherwise indicated.