scholarly journals The roles of pregn-5-ene-3β,20α-diol and 20α-hydroxy steroid dehydrogenase in the control of progesterone synthesis preceding parturition and lactogenesis in the rat

1970 ◽  
Vol 117 (2) ◽  
pp. 193-201 ◽  
Author(s):  
N. J. Kuhn ◽  
M. S. Briley
Keyword(s):  
Sharp Increase ◽  
Concentration Ratio ◽  
Corpora Lutea ◽  
Intact Cells ◽  
Progesterone Secretion ◽  
Progesterone Synthesis ◽  
Nad 4 ◽  
Relationship Of ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

1. The activity of 20α-hydroxy steroid dehydrogenase in rat ovarian corpora lutea increased at least 50-fold between 2 days before and 2 days after parturition, and then fell gradually during lactation. The activity of 3β-hydroxy Δ5-steroid dehydrogenase decreased by 50% at parturition but remained constant at other times. 2. The 20α-hydroxypregn-4-en-3-one/progesterone concentration ratio in the ovary fell tenfold between 1 day before and 1 day after parturition, in contrast with the increase of the ratio for these steroids in plasma. 3. Pregnenolone was metabolized in intact cells or cell-free systems either to pregn-5-ene-3β,20α-diol and then to 20α-hydroxypregn-4-en-3-one by 20α-hydroxy steroid dehydrogenase and 3β-hydroxy Δ5-steroid dehydrogenase respectively, or directly to progesterone by the latter enzyme. The relative activities of these pathways appeared to reflect the relative amounts of the two enzymes and the concentrations of their respective coenzymes NADPH and NAD+. 4. From these and other observations it was concluded that the cessation of progesterone secretion, which precedes parturition and lactogenesis at the end of pregnancy, is partly due to the redirected metabolism of pregnenolone away from progesterone and towards 20α-hydroxypregn-4-en-3-one as the secreted end product. This is primarily the consequence of the sharp increase in the activity of 20α-hydroxy steroid dehydrogenase. This mechanism is super-imposed on the already declining rate of net Δ4-steroid release by the ovary. 5. A relationship of these pathways to subcellular compartments of luteal cells is proposed.

scholarly journals A proposed sequence of hormones controlling the induction of luteal 20α-hydroxy steroid dehydrogenase and progesterone withdrawal in the late-pregnant rat

1976 ◽  
Vol 160 (3) ◽  
pp. 663-670 ◽  
Author(s):  
D H Smith ◽  
N J Kuhn
Keyword(s):  
Follicle Stimulating Hormone ◽  
Late Pregnancy ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Human Choriogonadotropin ◽  
Pregnant Mare Serum Gonadotropin ◽  
Progesterone Synthesis ◽  
Serum Gonadotropin ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

1. The previously reported induction of luteal 20α-hydroxy steroid dehydrogenase by administration of aminoglutethimide to late-pregnant rats was shown to be unaffected by prior removal of the foetuses. Aminoglutethimide therefore does not act via the foetuses in this context. 2. The ability of injected oestrogen to prevent the above induction was lost by delaying the injection for 12h after aminoglutethimide, although the increase in enzyme activity begins only after 24h. 3. Induction of 20α-hydroxy steroid dehydrogenase by foetoplacental removal on day 18 of pregnancy was inhibited by human choriogonadotropin, lutropin (luteinizing hormone) and pregnant-mare serum gonadotropin, but not by somatotropin (growth hormone), thyrotropin or follitropin (follicle-stimulating hormone) 4. Indomethacin blocked the normal induction of 20α-hydroxy steroid dehydrogenase in late pregnancy and that caused by aminoglutethimide. It partially blocked that caused by human choriogonadotropin given on days 19-20 and that caused by 2-bromo-α-ergocryptine on days 5-6, but failed to block that caused by human choriogonadotropin on days 15-16 or by foetoplacental removal on day 18 of pregnancy. 5. These findings, and the control of progesterone synthesis in late pregnancy, are interpreted in terms of a sequence of hormonal or enzymic syntheses, each of which is inhibited by the product of the preceding synthesis.

EFFECTS OF OESTRADIOL ON STEROID DEHYDROGENASE ACTIVITIES IN RAT CORPORA LUTEA

1980 ◽  
Vol 84 (3) ◽  
pp. 391-395 ◽  
Author(s):  
R. G. RODWAY ◽  
I. ROTHCHILD
Keyword(s):  
Enzyme Activity ◽  
Dehydrogenase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Corpora Lutea ◽  
Pregnant Rat ◽  
Oestradiol Treatment ◽  
Rapid Induction ◽  
Progesterone Secretion ◽  
Luteal Tissue ◽  
Steroid Dehydrogenase

The activities of 20α-hydroxysteroid dehydrogenase and 3β-hydroxysteroid dehydrogenase in rat corpora lutea during the second half of pregnancy were measured. In luteal tissue of the intact pregnant rat, 20α-hydroxysteroid dehydrogenase activity was undetectable between days 12 and 18 of pregnancy but appeared slowly after hypophysectomy and hysterectomy on day 12. Treatment of the hypophysectomized and hysterectomized animal with oestradiol delayed this increase until day 17, at which time a rapid induction of this enzyme occurred. In the normal pregnant rat mean luteal 3β-hydroxysteriod dehydrogenase activity increased between days 12 and 18 (P <0·05, Student's t-test) but fell rapidly after hypophysectomy and hysterectomy on day 12. Oestradiol treatment prevented this fall in activity and enzyme activity was not distinguishable from that of the intact rat. Progesterone secretion correlated well with the activities of these two enzymes in the three conditions examined.

ENZYMMUSTER UND PROGESTERONSYNTHESE

1967 ◽  
Vol 56 (3) ◽  
pp. 433-444 ◽  
Author(s):  
Hartmut Brandau ◽  
Karin Remmlinger ◽  
Wilfried Luh
Keyword(s):  
Citric Acid ◽  
Granulosa Cells ◽  
Citric Acid Cycle ◽  
Pentose Phosphate ◽  
Enzyme Activation ◽  
Corpora Lutea ◽  
Activity Levels ◽  
Acid Cycle ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

ABSTRACT During the maturation of follicles and corpora lutea in the rabbit ovary the activity levels of oxidoreductases of glycolysis, citric acid cycle, glycerophosphate cycle, pentose phosphate shunt as well as the Δ5,3β-hydroxy-steroid dehydrogenase were studied in granulosa cells by histochemical technique. While the oxidoreductases of the glycolysis, the citric acid cycle and glycerophosphate cycle show continuously unvaried activities a remarkable increase was found regarding the activities of NADPH2-supplying enzymes and Δ5,3β-hydroxy-steroid dehydrogenase before resp. after ovulation. According to these relations the granulosa cells of rabbit ovary cannot produce progesterone prior to 8 hours after ovulation. Furthermore, the analysis of the sequence and the functional role of enzyme activation in the granulosa cells allows some conclusions about the mechanism of gonadotrophin action influencing the metabolism of steroid hormone producing cells.

A metabolic stability determination of Tetrahydrothiazolopyridine derivative a selective 11β-hydroxy steroid dehydrogenase type 1 (11β-hsd1) inhibitor

2017 ◽  
Vol 8 (3) ◽  
Author(s):  
MURUGESH KANDASAMY ◽  
MUHAMMED SALIHIN ◽  
MALLIKARJUNA RAO PICHIKA ◽  
SLAVKO KOMARNYTSKY ◽  
THIRUMURUGAN RATHINASABAPATHY
Keyword(s):  
Metabolic Stability ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

Pineal denervation by cervical sympathetic ganglionectomy suppresses the role of photoperiod on pregnancy or pseudopregnancy, body weight and moulting periods in the mink (Mustela vison)

1985 ◽  
Vol 107 (1) ◽  
pp. 31-39 ◽  
Author(s):  
L. Martinet ◽  
D. Allain ◽  
Y. Chabi
Keyword(s):  
Body Weight ◽  
Environmental Factors ◽  
Prolactin Secretion ◽  
Corpora Lutea ◽  
Progesterone Secretion ◽  
Cervical Ganglion ◽  
Cervical Sympathetic ◽  
Implantation Period ◽  
Short Days

ABSTRACT In mink, termination of the delayed implantation period, following reactivation of the corpora lutea, and onset of the spring moult are associated with a rise in prolactin secretion triggered by increasing daylength, while decreasing daylength induces the autumn moult. To establish whether suppression of the function of the pineal rendered the mink unresponsive to daylength changes, the superior cervical ganglion was removed bilaterally 2–4 weeks before mating. Intact and operated females were then left outdoors or were put under a lighting regime of either 15 h light: 9 h darkness (15L: 9D) or 8L: 16D. In July, at the end of the spring moult, the 15L: 9D lighting regime was changed to one of 8L: 16D. Under artificial photoperiods ganglionectomy suppressed the stimulatory role of long days and the inhibitory role of short days on prolactin secretion, and consequently on progesterone secretion and spring moult. Neither was the autumn moult, induced early in intact females by the change to a short photoperiod, advanced in ganglionectomized females, showing that the latter were unresponsive to the artificial modification of the photoperiod. However, in animals kept outdoors, prolactin and progesterone secretion and spring moult were not changed by ganglionectomy. Increase in body weight and autumn moult were only slightly delayed by the operation suggesting that other environmental factors had replaced the synchronizing effect of the daylength changes. Alternatively the desynchronization between intact females responsive to photoperiodism and those rendered unresponsive may be too slow to be observed soon after ganglionectomy. J. Endocr. (1985) 107, 31–39

DIFFICULTIES IN THE DIAGNOSIS OF THE ADRENOGENITAL SYNDROME IN INFANCY

PEDIATRICS ◽  
1972 ◽  
Vol 49 (2) ◽  
pp. 198-205
Author(s):  
C. H. Shackleton ◽  
F. L. Mitchell ◽  
J. W. Farquhar
Keyword(s):  
Hydroxylase Deficiency ◽  
Adrenogenital Syndrome ◽  
Steroid Excretion ◽  
21 Hydroxylase Deficiency ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

Pregnanetriol was not excreted by an infant (7 days old) who was later shown to have a defect in steroid 21-hydroxylase. However, the excretion of this compound increased during the following days (1.2 mg on the thirteenth day of life). A high excretion of 3β-hydroxy-Δ steroids was the most noticeable abnormality in steroid excretion noted on the seventh day of life (e.g., 3β, 16α-dihydroxy-5-pregnen-20-one, 15 mg; 3β, 21-dihydroxy-5-pregnen-20-one, 1.4 mg and 3β, 16α-dihydroxy-5-androsten-17-one, 7.4 mg). This high 3β-hydroxy-Δ steroid excretion results in difficulties in distinguishing a defect in 3β-hydroxy steroid dehydrogenase from a 21-hydroxylase deficiency. At the age of 14 months the principal steroids excreted were those predominant in other cases of 21-hydroxylase deficiency, viz. pregnanetriol and 5β-pregnane-3α, 17α, 20α-triol-11-one (11-oxo-pregnanetriol).

Involvement of high-density lipoprotein in stimulatory effect of hormones supporting function of the bovine corpus luteum.

2003 ◽  
Vol 51 (1) ◽  
pp. 111-120 ◽  
Author(s):  
D. Skarżyński ◽  
J. Młynarczuk ◽  
J. Kotwica
Keyword(s):  
Luteinising Hormone ◽  
Density Lipoprotein ◽  
High Density ◽  
High Density Lipoproteins ◽  
Luteal Cells ◽  
Progesterone Secretion ◽  
Bovine Corpus Luteum ◽  
Progesterone Synthesis ◽  
Deficient Medium ◽  
Intracellular Pathway

The hypothesis that epinephrine (noradrenaline, NA) enhances utilisation of high-density lipoproteins (HDL) by bovine luteal cells and that this process involves phospholipase (PL) C and protein kinase (PK) C intracellular pathway was tested. Luteal cells from days 2-4, 5-10 or 11-17 of the oestrous cycle were pre-incubated for 20h. Subsequently DMEM/Ham's F-12 medium was replaced by fresh medium and the cells were treated for 6 h as follows: In Experiment I with HDL (5-75μg cholesterol per ml), NA, isoprenaline (ISO) or luteinising hormone (LH). In Experiment II cells were incubated for further 24h in deficient medium (without FCS) and next treated as in Experiment I. In Experiment III cells were stimulated with NA, ISO or LH alone and together with HDL. In Experiment IV cells were treated with PLC inhibitor (U-73122) or with PKC inhibitor (staurosporine) or stimulator (phorbol 12-myristrate 13-acetate) and with either NA, insulin or LH. Only luteal cells from days 5-10 of the cycle responded on HDL and β-mimetics (P<0.05). LH stimulated progesterone secretion from the luteal cells during all stages of the cycle (P<0.001). Cells incubated in deficient medium and supplemented with HDL secreted as much progesterone as those stimulated by LH in all stages of the cycle. Beta-mimetics were unable to enhance the stimulatory effect of HDL. Blockade of PLC had no influence on progesterone secretion from cells treated with either NA or LH, but this did impair the stimulatory effect of insulin (P<0.05). Similarly, blockade of PKC by staurosporine impaired (P<0.05) the effect of insulin only but not that observed after LH or NA treatment. We suggest that: (a) noradrenergic stimulation does not enhance utilisation of cholesterol from HDL for progesterone secretion; (b) the fasting of luteal cells seems to activate enzymes responsible for the progesterone synthesis; (c) effect of NA on progesterone secretion from luteal cells does not involve the PLC-PKC pathway.

Sign in / Sign up

Export Citation Format

Share Document