scholarly journals Age-dependent changes in the multiple forms of the soluble 17 β-hydroxysteroid dehydrogenase of female rabbit liver

1985 ◽  
Vol 225 (2) ◽  
pp. 391-398 ◽  
Author(s):  
G R Antoun ◽  
D G Williamson
Keyword(s):  
Dehydrogenase Activity ◽  
Specific Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Rabbit Liver ◽  
Molecular Heterogeneity ◽  
Special Role ◽  
Female Rabbit ◽  
Age Dependent ◽  
Androstane Series ◽  
Peptide Maps

The soluble NADP-dependent 17 beta-hydroxysteroid dehydrogenase activity of female rabbit liver increases with the age of the animal, the specific activity of the enzyme in the 56-day-old rabbit being 3 times that of the 28-day-old animal. The increase in activity is accompanied by a change in the molecular heterogeneity of the enzyme. Three forms (enzymes I, II and III) were identified in the liver cytosol of the 56-day-old female rabbit, whereas only one major form (enzyme IIIY) was present in the 28-day-old animal. Peptide maps of the four purified enzymes showed that there were minor differences in structure. The enzyme present in the liver of the 28-day-old rabbit was distinct from the three enzymes of the 56-day-old animal. All of the enzymes exhibited bifunctional activity, having 17 beta-hydroxysteroid dehydrogenase activity towards androgen and oestrogen substrates and 3 alpha-hydroxysteroid dehydrogenase activity towards androgens of the 5 beta-androstane series. The differences in substrate specificity of the enzymes paralleled their differences in structure. The data suggest that one enzyme (enzyme III) may have a special role in steroid metabolism during development in the female rabbit.

scholarly journals A 17 β-hydroxysteroid dehydrogenase of female rabbit liver cytosol. Purification and characterization of multiple forms of the enzyme

1985 ◽  
Vol 225 (2) ◽  
pp. 383-390 ◽  
Author(s):  
G R Antoun ◽  
I Brglez ◽  
D G Williamson
Keyword(s):  
Dehydrogenase Activity ◽  
Quaternary Structure ◽  
Hydroxysteroid Dehydrogenase ◽  
Rabbit Liver ◽  
Multiple Forms ◽  
Purification And Characterization ◽  
Enzyme Form ◽  
Female Rabbit ◽  
Androstane Series

Multiple forms of the soluble 17 beta-hydroxysteroid dehydrogenase of female rabbit liver were identified. NAD-dependent and NADP-dependent enzyme activities were separated by affinity chromatography on agarose-immobilized Procion Red HE3B, and three forms of the NADP-dependent enzyme activity were purified by chromatofocusing. These three enzyme forms are charge isomers and have no quaternary structure. The enzymes catalysed the C-17 oxidoreduction of oestrogens and androgens; with all enzyme forms the activity towards androgens was higher than that toward oestrogens. The enzymes also exhibited 3 alpha-hydroxysteroid dehydrogenase activity towards androgens of the 5 beta-androstane series. Comparison of the relative activities of the enzymes towards a number of oestrogen and androgen substrates revealed differences among the enzyme forms for both the oxidative and the reductive reactions. In particular, one enzyme form had a significantly lower Km for the 3 alpha-hydroxysteroid substrate and a higher 3 alpha-/17 beta-hydroxysteroid dehydrogenase activity ratio than the other two enzyme forms.

The Separation and Partial Purification of the Soluble 17α- and 17β-Hydroxysteroid Dehydrogenases of Rabbit Liver

1974 ◽  
Vol 52 (2) ◽  
pp. 120-125 ◽  
Author(s):  
Sadiq Hasnain ◽  
Denis G. Williamson
Keyword(s):  
Dehydrogenase Activity ◽  
Enzyme Activities ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Hydroxysteroid Dehydrogenase ◽  
Rabbit Liver ◽  
Partial Purification ◽  
17Β Estradiol ◽  
Derivatives Of ◽  
Estradiol 17Β

17-Hydroxysteroid dehydrogenase activity toward 17α-estradiol, 17β-estradiol, and the 3-glucuronide derivatives of these steroids has been demonstrated in the 105 000 × g supernatant of rabbit liver. DEAE-cellulose chromatography of the enzyme activities isolated by calcium phosphate gel fractionation and Sephadex gel filtration yielded a single 17α-hydroxysteroid dehydrogenase activity toward both 17α-estradiol and 17α-estradiol 3-glucuronide. However, separate 17β-hydroxysteroid dehydrogenase activities toward 17β-estradiol and 17β-estradiol 3-glucuronide were obtained. Further purification of the 17α-hydroxysteroid dehydrogenase fraction by isoelectric focusing resulted in multiple peaks of activity toward 17α-estradiol and 17α-estradiol 3-glucuronide. One of these enzyme activities was highly specific for the 3-glucuronide derivative, it being essentially devoid of activity toward 17α-estradiol.

Age-associated changes in the estrogen receptor-active proteases of female rabbit liver

1990 ◽  
Vol 68 (7-8) ◽  
pp. 1065-1070
Author(s):  
Denis G. Williamson ◽  
Marie M. Song
Keyword(s):  
Molecular Weight ◽  
Estrogen Receptor ◽  
High Molecular Weight ◽  
Protease Activity ◽  
Young Animal ◽  
Rabbit Liver ◽  
Liver Cytosol ◽  
Female Rabbit ◽  
Age Dependent ◽  
Active Protease

Female rabbit liver cytosol contains a receptor-modifying activity that converts the 250 000 estrogen receptor of liver and uterine cytosol to a 37 000 form. There is an age-dependent increase in this receptor-active protease and in the general protease activity of rabbit liver cytosol, measured with [14C]casein. Sephacryl S-200 chromatography of liver cytosol shows that in the young animal (5 weeks old) the major receptor-modifying activity elutes near the void volume, while in the older animal (13 weeks old) activities having lower molecular weights are present. The general protease activity elution profile is similar to the receptor-active protease profile for the 5-week-old rabbit but not the 13-week-old rabbit. The liver cytosol of the older animal has a high molecular weight protease active toward [14C]casein but not toward the estrogen receptor. The changes in the estrogen receptor forms and the receptor-modifying activity profiles of liver cytosol that occur during development in the rabbit suggest that receptor-modifying activity may initially be associated with the estrogen receptor to form a high molecular weight complex.Key words: liver, estrogen receptor, proteolysis, age dependent.

AGEING AND OVARIAN Δ5-3β-HYDROXYSTEROID DEHYDROGENASE IN THE PREGNANT MOUSE

1976 ◽  
Vol 70 (2) ◽  
pp. 183-187 ◽  
Author(s):  
W. B. WEHRENBERG ◽  
S. F. GOTTLIEB ◽  
E. D. ALBRECHT
Keyword(s):  
Dehydrogenase Activity ◽  
Specific Activity ◽  
Age Groups ◽  
Total Content ◽  
Hydroxysteroid Dehydrogenase ◽  
Pregnant Mouse ◽  
Foetal Death ◽  
Luteal Regression ◽  
Aged Mice

SUMMARY Aged (12- to 14-month-old) C57BL oestrous mice exhibited significantly lower (P < 0·001) ovarian Δ5-3β-hydroxysteroid dehydrogenase (3β-HSD) concentration, specific activity and total content than young (3-month-old) oestrous mice, suggesting a decrease in the potential of the older animals to produce ovarian Δ4-3-oxosteroids. Mice in both age groups maintaining pregnancy to 10 or 18 days post coitum (p.c.) had similar values for activity of ovarian 3β-HSD. In the aged females in which foetal resorption had occurred, the majority of foetuses had been resorbed by 10 days p.c. However, ovarian 3β-HSD activity in these animals was not significantly different from that of young or aged mice maintaining pregnancy. By day 18, however, ovarian dehydrogenase activity in aged females failing to maintain pregnancy had decreased significantly. It is suggested that foetal death in aged mice is not the result of a deficiency in ovarian 3β-HSD, but rather may initiate luteal regression and consequently a decline in 3β-HSD.

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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