Suppression of 20α-hydroxysteroid dehydrogenase activity in cultured rat luteal cells by prolactin

Lahav, Michal; Lamprecht, Sergio A.; Amsterdam, Avraham; Lindner, H. R.

doi:10.1016/0303-7207(77)90103-4

Cited by 33 publications

(6 citation statements)

References 24 publications

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“…In the rat 20a-HSD is present in high concentrations in the regressing corpus luteum (Pupkin et al, 1966;Lahav et al, 1977). At 38 days of age corpora lutea are present in 50% of mice of the strain used in this study (Halpin et al, 1986) and this coincides with an increase in 20a-HSD activity which is sustained up to 60 days.…”

Section: Discussionmentioning

confidence: 55%

Ovarian steroid metabolism during post-natal development in the normal mouse and in the adult hypogonadal (hpg) mouse

Mannan

O’Shaughnessy²

1988

Reproduction

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Summary. Ovarian steroid metabolism was investigated (i) during development in a normal inbred strain in which post-natal follicle growth has been described and (ii) the major metabolite formed at all ages while androstenedione was the major androgen. Between 7 and 21 days there was an overall increase in steroidogenic enzyme activity with a peak of 5\g=a\-reductasebetween 21 and 29 days. The major metabolite of progesterone around puberty was 5\g=a\-pregnane-3\g=a\-ol-20-one. A sharp increase in 20\ g=a\ \ x=r eq-\ hydroxysteroid dehydrogenase was observed after 38 days due, presumably, to the appearance of corpora lutea. Unlike the rat, androstanediol levels were low at all ages.Oestradiol was the major oestrogen formed from androstenedione with a peak of production at 38 days. In the adult hpg mouse metabolism was similar to that of the 7-day normal mouse although 17-ketosteroid reductase and aromatase levels were very low compared to normal animals of any age, indicating that gonadotrophin stimulation is involved in the expression of activity by these enzymes.

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Section: Discussionmentioning

confidence: 55%

Ovarian steroid metabolism during post-natal development in the normal mouse and in the adult hypogonadal (hpg) mouse

Mannan

O’Shaughnessy²

1988

Reproduction

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“…This is supported by the finding that the production of this steroid is much higher in all of the clones than in freshly isolated cells. Moreover, 20a-dihydroprogesterone production is also increased in cultures of other Leydig tumor cells (8,9), normal or malignant adrenocortical cells (3,5,25), and normal granulosa cells (26).…”

Section: Discussionmentioning

confidence: 99%

Characterization of Several Clonal Lines of Cultured Ley dig Tumor Cells: Gonadotropin Receptors and Steroidogenic Responses*

Ascoli¹

1981

Endocrinology

565

281

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Several clonal lines of cultured Leydig tumor cells have been established and characterized in terms of gonadotropin receptors and steroid production. Although freshly isolated cells derived from the M5480P tumor have functional hCG receptors, only two of the five clonal lines established were shown to bind significant quantities of hCG. In these clones, steroid production can be stimulated to the same extent by hCG, cholera toxin, and 8-Br-cAMP. The other three clones bind a small amount of hCG and respond to the hormone with a marginal increase in steroidogenesis. Steroid production, however, is significantly stimulated by cholera toxin or 8-Br-cAMP. A comparison of the steroids produced by freshly isolated cells and two of the clones revealed some changes in the steroidogenic pathway. The most obvious change is an increase in the ability of the cultured cells to synthesize 20 alpha-dihydroprogesterone (20 alpha-hydroxypregn-4-en-3-one). These clonal lines may provide a suitable model system for the study of gonadotropin actions and regulation of the expression of differentiated functions of Leydig cells.

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“…However, Armstrong (1968) and Lamprecht et al (1975) showed that the administration of PRL to hypophysectomized or PGF2a treated rats with luteinized ovaries partially prevented increased 20a-hydroxysteroid dehydrogenase activity. In addition, Lahav et al (1977) have shown suppression of 20a-hydroxysteroid dehydrogenase activity in cultured rat luteal cells by PRL. Moreover, the administration of PRL alone did not increase the serum 20a-DHP levels in the superluteinized rat 8 days after HCG treatment (Torjesen, unpublished observation).…”

Section: Discussionmentioning

confidence: 96%

“…The PGF2a induced luteolysis of the superluteinized rat (Parlow 1961) ovary is characterized by an immediate decrease in the serum levels of pro¬ gesterone followed by increased prolactin (PRL) 3 to 6 h later and increased 20a-dihydroprogesterone (20a-DHP) 6 to 9 h after the prostaglandin (Torjesen et al 1978), suggesting a causal relationship between increased PRL and 20a-DHP. There are, however, conflicting data in the literature on the effect of PRL on the 20a-hydroxysteroid dehydrogenase of the rat ovary (Strauss 8c Stambaugh 1974;Lahav et al 1977).…”

mentioning

confidence: 93%

PROLACTIN AND THE REGULATION OF 20α-Dihydroprogesterone SECRETION OF THE SUPER-LUTEINIZED RAT OVARY DURING LUTEOLYSIS INDUCED BY a PROSTAGLANDIN F2α ANALOGUE

Torjesen¹,

Dahlin²,

Haug³

et al. 1978

Acta Endocrinologica

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Twenty-five day old female rats were treated with pregnant mare's serum gonadotrophin (PMSG) and human chorionic gonadotrophin (HCG) to achieve a state of luteinization. Eight days after the HCG administration luteolysis was induced by a subcutaneous injection of 5 \g=m\g of the prostaglandin F2\g=a\analogue cloprostenol (Estrumate\s=r\, ICI 80996). In animals treated with 2-Br-\g=a\-ergocryptine(BEC), administration of cloprostenol decreased serum progesterone levels from 580 to 20 ng/ml in 5 h and progesterone remained low for the next 18 h. The serum levels of 20\g=a\-dihydroprogesterone(20\g=a\-DHP) and prolactin (PRL) remained at pre-treatment values (20\g=a\-DHP 85 to 170 ng/ml; PRL less than 5 ng/ml) throughout the observation period. When animals treated with both BEC and cloprostenol were given PRL 5 h after the prostaglandin injection, an increased 20\g=a\-DHPlevel (630 ng/ml) was found 23 h after the cloprostenol administration, while the progesterone level was decreased (70 ng/ml). These findings were similar to the observations following cloprostenol treatment alone. The study indicates a causal relationship between the increase in the serum levels of PRL and 20\g=a\-DHPobserved after PGF2\g=a\ induced luteolysis in rats with superluteinized ovaries. Prostaglandin F2a (PGF2a) administration induces luteolysis in a number of animal species and appears to be the physiological luteolytic factor of uterine origin in most mammals including the rat (for a review see Horton 8c Poyser 1976). The PGF2a induced luteolysis of the superluteinized rat (Parlow 1961) 625 Acta endocr. 87, 3 40 The Hormone and Isotope Laboratory, Aker Hospital, Oslo 5

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Suppression of 20α-hydroxysteroid dehydrogenase activity in cultured rat luteal cells by prolactin

Cited by 33 publications

References 24 publications

Ovarian steroid metabolism during post-natal development in the normal mouse and in the adult hypogonadal (hpg) mouse

Ovarian steroid metabolism during post-natal development in the normal mouse and in the adult hypogonadal (hpg) mouse

Characterization of Several Clonal Lines of Cultured Ley dig Tumor Cells: Gonadotropin Receptors and Steroidogenic Responses*

PROLACTIN AND THE REGULATION OF 20α-Dihydroprogesterone SECRETION OF THE SUPER-LUTEINIZED RAT OVARY DURING LUTEOLYSIS INDUCED BY a PROSTAGLANDIN F2α ANALOGUE

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