Stimulation of androgen-dependent gene expression by the adrenal precursors dehydroepiandrosterone and androstenedione in the rat ventral prostate
- Laval Univ. Medical Center, Quebec (Canada)
Androgens play a major role in the development, growth, and function of accessory sexual organs, especially the prostate. However, the testis is not the sole source of circulating androgens in man, since the adrenal gland secretes dehydroepiandrosterone (DHEA), DHEA sulfate, and androstenedione (delta 4-dione) in large quantities. The aim of the present study was to investigate the effect of plasma concentrations of DHEA and delta 4-dione similar to those found in adult man on sensitive and specific markers of androgen action in the rat ventral prostate. In addition to ventral prostate weight, we have measured the steady state levels of the mRNAs encoding the C1 component of rat prostatic binding protein (PBP-C1) and spermine-binding protein (SBP) using 35S-labeled cDNA probes for in situ hybridization. One week after castration, ventral prostate weight fell 84%, while prostatic 5 alpha-dihydrotestosterone (DHT) and androgen-dependent mRNAs were undetectable. When administered via Silastic implants to castrated adult rats for 1 week, plasma concentrations of 1.37 +/- 0.06 ng/ml DHEA or 0.43 +/- 0.08 ng/ml delta 4-dione independently caused increases in ventral prostate weight to 33% and 65% of normal values, respectively. The same plasma levels of DHEA and delta 4-dione resulted in high intraprostatic levels of DHT to 1.19 +/- 0.34 and 3.66 +/- 0.89 ng/g tissue, respectively. Furthermore, DHEA caused an increase in the steady state levels of PBP-C1 and SBP mRNAs to 50% and 57% of the normal state, respectively, while delta 4-dione caused increases corresponding to 80% and 119% of control values, respectively. Castrated adult rats receiving testosterone at a concentration of 1.66 +/- 0.37 ng/ml plasma maintained normal ventral prostate weight and gene expression levels.
- OSTI ID:
- 5517120
- Journal Information:
- Endocrinology; (USA), Journal Name: Endocrinology; (USA) Vol. 124:6; ISSN ENDOA; ISSN 0013-7227
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
ADRENAL GLANDS
ANDROGENS
ANDROSTANES
ANDROSTENEDIONE
ANIMALS
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
DAYS LIVING RADIOISOTOPES
DNA HYBRIDIZATION
ENDOCRINE GLANDS
EVEN-ODD NUCLEI
GENE REGULATION
GENES
GLANDS
HORMONES
HYBRIDIZATION
HYDROXY COMPOUNDS
HYDROXYANDROSTENONE
ISOTOPES
KETONES
KINETICS
LIGHT NUCLEI
MALE GENITALS
MAMMALS
MESSENGER-RNA
NUCLEI
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PROSTATE
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RNA
RODENTS
STEROID HORMONES
STEROIDS
SULFUR 35
SULFUR ISOTOPES
TRANSCRIPTION
VERTEBRATES