scholarly journals Decline with Age in the Rate of Reduction of Progesterone to 20a-Hydroxypregn-4-en-3-one in the Blood of Perinatal Ruminants

1983 ◽  
Vol 36 (2) ◽  
pp. 183 ◽  
Author(s):  
CD Nancarrow
Keyword(s):  
Longitudinal Studies ◽  
Dehydrogenase Activity ◽  
Gestational Age ◽  
Hydroxysteroid Dehydrogenase ◽  
Adult Type ◽  
Sheep Blood ◽  
New Born ◽  
Final Volume ◽  
O 43

The activity of the enzyme 20IX-hydroxysteroid dehydrogenase present in erythrocytes of foetal and new-born ruminants has been determined by incubating 0�1 ml blood with 0�16,umol [4_'4C]_ progesterone for 15 min at 39�C in a final volume of 2 ml buffered saline. It was found that the activity, measured as ,umol 20IX-hydroxypregn-4-en-3-one produced from progesterone per millilitre of erythrocytes per hour, declined from levels at birth as high as 1'50,umol for sheep, 0'50,umol for goats and O' 43 ,umol for cattle to levels of around 0'11, O' 08 and O' 04 ,umol respectively by 30-60 days of age. This decline in activity was also apparent in blood taken from sheep foetuses in which longitudinal studies were possible and appeared to have begun prior to 35 days before term. The highest activity obtained was 2� 59 ,umol for foetal sheep blood taken at 115 days of gestation. It is suggested that the observed decline in 20IX-hydroxysteroid dehydrogenase activity is a function of the replacement of foetal erythrocytes with adult-type erythrocytes which begins around 120 days of gestational age and that the role of the enzyme is to maintain an appropriate progestational environment within the foetoplacental unit.

scholarly journals Studies on the role of zinc in parturition in the rat

1983 ◽  
Vol 210 (3) ◽  
pp. 761-767 ◽  
Author(s):  
G E Bunce ◽  
G R Wilson ◽  
C F Mills ◽  
A Klopper
Keyword(s):  
Dehydrogenase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Zn Deficiency ◽  
Progesterone Concentration ◽  
Pregnant Rats ◽  
Plasma Progesterone ◽  
Prostaglandin F2 Alpha

1. Pregnant rats were fed either low (less than 1 p.p.m.) Zn or control (40 p.p.m. Zn) diets from day 10 of gestation. They were killed at intervals during the last 96 h preceding the normal time for onset of parturition, and differences in plasma progesterone, oestradiol-17 beta and ovarian 20 alpha-hydroxysteroid dehydrogenase were assessed. 2. Gestation was prolonged in Zn-deficient rats. 3. Although the preparturient decline in plasma progesterone began at the same time in all groups, at term, plasma progesterone concentration in Zn-deficient rats remained significantly higher than in normal females. 4. Induction of ovarian 20 alpha-hydroxysteroid dehydrogenase activity was delayed by about 8 h by Zn deficiency. This delay was not observed if prostaglandin F2 alpha was injected previously. 5. The results suggest a Zn-dependent step(s) in uterine synthesis and/or release of prostanoids.

scholarly journals Lysophosphatic acid modulates prostaglandin secretion in the bovine uterus

Reproduction ◽  
2009 ◽  
Vol 137 (1) ◽  
pp. 95-105 ◽  
Author(s):  
Izabela Woclawek-Potocka ◽  
Junichi Komiyama ◽  
Jean Sebastian Saulnier-Blache ◽  
Edyta Brzezicka ◽  
Mamadou Moussa Bah ◽  
...  
Keyword(s):  
Gene Expression ◽  
Estrous Cycle ◽  
Dehydrogenase Activity ◽  
Lysophosphatidic Acid ◽  
Early Pregnancy ◽  
Reproductive Tract ◽  
Hydroxysteroid Dehydrogenase ◽  
Lpa Receptor

Lysophosphatidic acid (LPA) modulates prostaglandin (PG) synthesis via LPA receptor 3 (LPAR3) in the murine endometrium. The lack of functional LPAR3 in mice may lead to embryo mortality. In the present study, we examined the role of LPA in the bovine uterus. We confirmed that LPA is locally produced and released from the bovine endometrium. Moreover, there are enzymes involved in LPA synthesis (phospholipase(PL)D2and PLA2G1B) in the bovine endometrium during estrous cycle and early pregnancy. Expression of the receptor for LPA (LPAR1) was positively correlated with the expression ofPGE2synthase(PGES) and negatively correlated with the expression ofPGF2αsynthase(aldose reductase with 20 α-hydroxysteroid dehydrogenase activity –PGFS) during early pregnancy.In vivoLPA induced P4 and PGE2secretion was inhibited by LPAR1 antagonist (Ki16425). The overall results indicate that LPA is locally produced and released from the bovine endometrium. Moreover,LPAR1gene expression in the endometrium during the estrous cycle and early pregnancy indicates that LPA may play autocrine and/or paracrine roles in the bovine uterus.LPAR1gene expression is positively correlated with the expression of the enzyme responsible for luteotropic PGE2production (PGES) in endometrium. In cow, LPA stimulates P4 and PGE2secretion. Thus, LPA in the bovine reproductive tract may indirectly (via endometrium) or directly support corpus luteum action via the increase of P4 synthesis and the increase of PGE2/PGF2αratio. It suggests that LPA may serve as an important factor in the maintenance of early pregnancy in cow.

THE ROLE OF PROLACTIN IN THE REGULATION OF TESTICULAR FUNCTION: THE EFFECT OF PROLACTIN AND LUTEINIZING HORMONE ON 3β-HYDROXYSTEROID DEHYDROGENASE ACTIVITY IN THE TESTES OF MICE AND RATS

1971 ◽  
Vol 50 (4) ◽  
pp. 619-623 ◽  
Author(s):  
A. A. HAFIEZ ◽  
J. E: PHILPOTT ◽  
A. BARTKE
Keyword(s):  
Luteinizing Hormone ◽  
Dehydrogenase Activity ◽  
Normal Mouse ◽  
Hydroxysteroid Dehydrogenase ◽  
Testicular Function ◽  
Hypophysectomized Rats ◽  
Dwarf Mice

SUMMARY Administration of 100 μg prolactin twice daily for 3 days increased 3β-hydroxysteroid dehydrogenase (3β-HSD) activity in the testes of dwarf mice compared with that found in the normal mouse. In hypophysectomized rats, prolactin (200 μg, same regimen) was without effect when given alone, whereas 5 μg luteinizing hormone (LH) alone injected twice daily, increased 3β-HSD activity to above normal. When prolactin and LH were administered in combination, 3β-HSD activity was raised to normal levels only.

Relationship between glucose and 20α-hydroxysteroid dehydrogenase in fetal sheep erythrocytes

1984 ◽  
Vol 101 (2) ◽  
pp. 131-139
Author(s):  
C. D. Nancarrow ◽  
P. J. Connell ◽  
D. Stevens
Keyword(s):  
Enzyme Activity ◽  
Dehydrogenase Activity ◽  
Plasma Glucose ◽  
Whole Blood ◽  
Hydroxysteroid Dehydrogenase ◽  
Adult Type ◽  
Fetal Sheep ◽  
Sheep Erythrocytes ◽  
Fetal Plasma ◽  
Rate Of Reaction

ABSTRACT We have examined whether glucose supply to fetal sheep erythrocytes limits the rate of 20α-reduction of progesterone in blood and as such is associated with the progressive loss of 20α-hydroxysteroid dehydrogenase activity which has been observed from 30 days before term. Enzyme activity in erythrocytes depleted of glucose by washing was regained in the presence of at least 0·167 mmol glucose/l. The cofactor NADPH was necessary to support the reaction in lysed cells. Addition of glucose to whole blood diluted 20-fold for assay of 20α-hydroxysteroid dehydrogenase did not increase the rate of reaction. Infusion of dextrose to increase fetal plasma glucose concentrations had no effect on 20α-hydroxysteroid dehydrogenase activity. Over the period from 114 to 137 days of gestation, both dextrose- and saline-infused fetuses showed a decline in enzyme activity from a combined mean of 1·45 ± 0·21 (s.e.m.) to a mean of 0·78 ± 0·18 μmol/ml erythrocytes per h. Fetal leucocytes did not contribute significantly to the activity of 20α-hydroxysteroid dehydrogenase in whole blood. The rate of 20α-reduction of progesterone in the blood of eight fetuses with indwelling carotid catheters declined from 2·31 ± 0·09 μmol/ml erythrocytes per h at 90–95 days of gestation to 0·73 ± 0·04 μmol/ml per h at 141–145 days. However, a consistent decline was only observed after 116–120 days. The apparent equilibrium position for progesterone reduction to 20α-dihydroprogesterone varied between 83·9 ± 1·8 and 65·7 ± 4·2%. Thus, it appears that the decline in 20α-hydroxysteroid dehydrogenase activity which occurs in whole blood of sheep fetuses during the last 30 days of gestation is due to dilution of the fetal erythrocytes with adult-type erythrocytes rather than development of limiting concentrations of plasma glucose. J. Endocr. (1984) 101, 131–139

METABOLISM OF ANDROGENS IN VITRO BY HUMAN FOETAL SKIN

1976 ◽  
Vol 70 (3) ◽  
pp. 491-499 ◽  
Author(s):  
F. SHARP ◽  
J. B. HAY ◽  
M. B. HODGINS
Keyword(s):  
Gestational Age ◽  
Enzyme Activities ◽  
Histochemical Study ◽  
Reductase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Sebaceous Glands ◽  
Isomerase Activity ◽  
Human Foetuses

SUMMARY Fresh scalp, genital, chest and axillary skin from human foetuses of 12–41 weeks' maturity was incubated in Krebs' improved Ringer I medium with [7α-3H]dehydroepiandrosterone, [7α-3H]testosterone and [7α-3H]androstenedione. The metabolites identified were androstenedione, 5α-androstane-3,17-dione, androsterone, 3-epiandrosterone, 5α-dihydrotestosterone, 5α-androstane-3α,17β-diol, 5α-androstane-3β,17β-diol, 5-androstene-3β,17β-diol and testosterone. The results provide evidence for the presence of 3β-hydroxysteroid dehydrogenase, Δ4–5 isomerase, 17β-hydroxysteroid dehydrogenase, Δ4-3-oxosteroid-5α-reductase and 3α-hydroxysteroid dehydrogenase in human foetal skin. There were quantitative differences in the various enzyme activities between different body sites and skin specimens of different gestational age. 5α-Reductase activity was particularly high in genital skin. 3β-Hydroxysteroid dehydrogenase Δ4–5 isomerase activity was low in skin from a 12-week foetus, but high in skin specimens from 28-, 38- and 41-week foetuses. 17β-Hydroxysteroid dehydrogenase activity was already high in the skin of the 12-week foetus and remained so in the older foetuses. These results were correlated with the development of the foetal sebaceous glands, and were in general agreement with a parallel enzyme histochemical study. The role of androgen metabolism in human foetal skin is discussed.

THE INFLUENCE OF HAEMOGLOBIN-S AND G6PD DEFICIENCY ON THE ACTIVITY OF THE 17β-HYDROXYSTEROID DEHYDROGENASE OF INTACT HUMAN ERYTHROCYTES

1974 ◽  
Vol 75 (4) ◽  
pp. 793-800
Author(s):  
A. O. Sogbesan ◽  
O. A. Dada ◽  
B. Kwaku Adadevoh
Keyword(s):  
Enzyme Activity ◽  
Dehydrogenase Activity ◽  
Sex Steroids ◽  
G6pd Deficiency ◽  
Incubation Medium ◽  
Hydroxysteroid Dehydrogenase ◽  
G6pd Activity ◽  
Reverse Transformation ◽  
Oxidative Transformation ◽  
Haemoglobin S

ABSTRACT The 17β-hydroxysteroid dehydrogenase activity in intact erythrocytes of Nigerian patients, in particular with regard to haemoglobin genotypes and G6PD* activity was studied. The G6PD activity of the erythrocyte did not affect the oxidative transformation of testosterone to androstenedione and of oestradiol to oestrone. The reduction (reverse transformation) was inhibited in G6PD-deficient erythrocytes but this inhibition was offset by the addition of 0.025 m glucose to the incubation medium. The per cent oxidation transformation of testosterone was higher in Hb-AA than in Hb-SS erythrocytes. It is suggested that the differences may be a result of either lower enzyme activity in the Hb-SS erythrocytes or of differences in the uptake and possibly binding of sex steroids by intact Hb-SS and Hb-AA erythrocytes.

ACUTE ENZYME HISTOCHEMICAL CHANGES IN THE ZONA GLOMERULOSA OF THE RAT ADRENAL CORTEX

1968 ◽  
Vol 59 (3) ◽  
pp. 508-518
Author(s):  
J. D. Elema ◽  
M. J. Hardonk ◽  
Joh, Koudstaal ◽  
A. Arends
Keyword(s):  
Peritoneal Dialysis ◽  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Adrenal Cortex ◽  
Isocitrate Dehydrogenase ◽  
Hydroxysteroid Dehydrogenase ◽  
Zona Glomerulosa ◽  
Acute Changes ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Histochemical Changes

ABSTRACT Acute changes in glucose-6-phosphate dehydrogenase and isocitrate dehydrogenase activity in the zona glomerulosa of the rat adrenal cortex were induced by peritoneal dialysis with 5 % glucose. Although less clear, the activity of 3β-ol-hydroxysteroid dehydrogenase also seemed to increase as well. No changes were seen in the activity of succinate dehydrogenase. Dialysis with 0.9 % NaCl had no effect on any of the enzymes investigated. The possible significance of these observations is discussed.

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