Regulation of 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase expression and activity in the hypophysectomized rat ovary: Interactions between the stimulatory effect of human chorionic gonadotropin and the luteolytic effect of prolactin

Journal Article · Sat Dec 01 00:00:00 EST 1990 · Endocrinology; (USA)

DOI:https://doi.org/10.1210/endo-127-6-2726· OSTI ID:6171363

Martel, C; Labrie, C; Dupont, E; Couet, J; Trudel, C; Rheaume, E; Simard, J; Luu-The, V; Pelletier, G; Labrie, F ^[1]

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1. CHUL Research Center, Quebec (Canada)

The enzyme 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase (3 beta-HSD) catalyzes an obligatory step in the conversion of pregnenolone and other 5-ene-3 beta-hydroxysteroids into progesterone as well as precursors of all androgens and estrogens in the ovary. Since 3 beta-HSD is likely to be an important target for regulation by pituitary hormones, we have studied the effect of chronic treatment with LH (hCG), FSH, and PRL on ovarian 3 beta-HSD expression and activity in hypophysectomized adult female rats. Human CG (hCG) (10 IU, twice a day (bid)), ovine FSH (0.5 microgram, bid), and ovine PRL (1 mg, bid) were administered, singly or in combination, for a period of 10 days starting 15 days after hypophysectomy. In hypophysectomized rats, PRL exerted a potent inhibitory effect on all the parameters studied. In fact, PRL caused a 81% decrease in ovarian 3 beta-HSD mRNA content accompanied by a similar decrease in 3 beta-HSD activity and protein levels. In addition, ovarian weight decreased by 40% whereas serum progesterone fell dramatically from 1.92 nmol/liter to undetectable levels after treatment with PRL. Whereas hCG alone had only slight stimulatory effects on 3 beta-HSD mRNA, protein content and activity levels, treatment with the gonadotropin partially or completely reversed the potent inhibitory effects of oPRL on all the parameters measured. FSH, on the other hand, had no significant effect on 3 beta-HSD expression and activity. In situ hybridization experiments using the 35S-labeled rat ovary 3 beta-HSD cDNA probe show that the inhibitory effect of PRL is exerted primarily on luteal cell 3 beta-HSD expression and activity. On the other hand, it can be seen that hCG stimulates 3 beta-HSD mRNA accumulation in interstitial cells.

• OSTI ID: 6171363
• Journal Information: Endocrinology; (USA), Vol. 127:6; ISSN 0013-7227
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
GONADOTROPINS
BIOCHEMICAL REACTION KINETICS
OVARIES
GENE REGULATION
OXIDOREDUCTASES
ENZYME ACTIVITY
PROGESTERONE
BIOSYNTHESIS
AUTORADIOGRAPHY
FSH
LH
LTH
RATS
SULFUR 35
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
DAYS LIVING RADIOISOTOPES
ENZYMES
EVEN-ODD NUCLEI
FEMALE GENITALS
GONADS
HORMONES
ISOTOPES
KETONES
KINETICS
LIGHT NUCLEI
MAMMALS
NUCLEI
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PITUITARY HORMONES
PREGNANES
RADIOISOTOPES
REACTION KINETICS
RODENTS
STEROID HORMONES
STEROIDS
SULFUR ISOTOPES
SYNTHESIS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques