Differential expression of 11β-hydroxysteroid dehydrogenase 1 and 2 in the developing ovine fetal liver and kidney

1995 ◽  
Vol 147 (3) ◽  
pp. 405-411 ◽  
Author(s):  
D A Langlois ◽  
S G Matthews ◽  
M Yu ◽  
K Yang
Keyword(s):  
Dehydrogenase Activity ◽  
Fetal Liver ◽  
Reductase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Fetal Kidney ◽  
Fetal Sheep ◽  
Parallel Increase ◽  
Tissue Homogenates ◽  
Liver And Kidney ◽  
Ovine Fetal

Abstract In adult mammals, liver and kidney are the two major sites of biosynthesis for 11β-hydroxysteroid dehydrogenase (11β-HSD) 1 and 2 respectively. In the present study, the expression of these two isozymes in the developing ovine fetal liver and kidney was characterized. Livers and kidneys were obtained from fetal sheep at days 85, 100–120 and 140–143 of gestation (term=145 days). Tissue levels of 11β-HSD2 mRNA were assessed by Northern blot analysis. 11β-HSD dehydrogenase and reductase activities in tissue homogenates were determined by a radiometric conversion assay using cortisol and cortisone as physiological substrates respectively. The unidirectional 11β-HSD2 dehydrogenase activity was identified by its distinct co-factor preference (NAD), and by its unique ability to metabolize dexamethasone (Dex). In the liver, 11β-HSD1 dehydrogenase and reductase activities were present by day 85, and their levels did not change between days 85 and 100–120 but increased more than twofold at days 140–143. This was consistent with changes we reported previously in the fetal hepatic 11β-HSD1 mRNA. 11β-HSD1 reductase activity was always higher than the dehydrogenase activity. 11β-HSD2 mRNA and activity were undetectable in the fetal liver at all three ages. By contrast, 11β-HSD2 mRNA was present in the fetal kidney by day 85, and its abundance increased progressively thereafter. There was a parallel increase in the renal 11β-HSD2 activity. Dex was also converted to 11-dehydro-Dex by the fetal kidney. In keeping with the absence of the full-length 11β-HSD1 mRNA, 11β-HSD1 activity was undetectable in the kidney. These results indicate that (1) 11β-HSD1 and 2 genes are differentially expressed and regulated in the fetal liver and kidney during development, (2) since the hepatic 11β-HSD1 reductase activity is always higher than the dehydrogenase activity, the fetal liver may be a potential extra-adrenal source of cortisol, and (3) 11β-HSD2 in the kidney may play a very important role in protecting the fetus from elevated levels of bioactive glucocorticoids. Journal of Endocrinology (1995) 147, 405–411

Effects of sustained hypoxaemia with 72 hours recovery on 11β-hydroxysteroid dehydrogenase types 1 and 2 gene expression in near-term fetal sheep

1997 ◽  
Vol 9 (8) ◽  
pp. 755 ◽  
Author(s):  
H. Asano ◽  
K. Shearman ◽  
A. Darnel ◽  
B. S. Richardson ◽  
K. Yang
Keyword(s):  
Metabolic Acidosis ◽  
Fetal Liver ◽  
Time Lag ◽  
Placental Tissue ◽  
Hydroxysteroid Dehydrogenase ◽  
Tissue Level ◽  
Fetal Sheep ◽  
Liver And Kidney ◽  
Near Term ◽  
Inspired Oxygen

The study examined the effects of 8 h sustained hypoxaemia, with 72 h recovery, on the expression of 11β-hydroxysteroid dehydrogenase (11b-HSD) types 1 and 2 in near-term fetal sheep. Placental tissue and fetal liver and kidney were collected at Days 135–138 gestation 72 h after 8 h sustained hypoxaemia induced by lowering maternal inspired oxygen with (n= 9) and without (n = 6) metabolic acidosis or after 8 h normoxia (n = 6). In hypoxic fetuses with metabolic acidosis, a significant increase in the level of 11β-HSD2 mRNA in the kidney compared with controls was correlated significantly with degree of associated fetal acidaemia, but there were no corresponding increases in the tissue level of 11β-HSD2 activity. Hence, a time lag may exist between the mRNA and activity. Alternatively, the translation of 11β-HSD2 mRNA may be inhibited. In contrast, levels of 11β-HSD1 mRNA in the placenta and fetal liver were unchanged 72 h after sustained hypoxaemia. These results indicate that sustained fetal hypoxaemia with metabolic acidosis selectively up-regulates 11β-HSD2 mRNA expression in the near-term fetal sheep kidney. This may be a re-bound effect at 72 h following an initial down-regulation as observed in a previous study.

Ontogeny of 11 beta-hydroxysteroid dehydrogenase in ovine fetal kidney and lung

1995 ◽  
Vol 7 (5) ◽  
pp. 1329 ◽  
Author(s):  
CE Wood ◽  
R Srun
Keyword(s):  
Gestational Age ◽  
High Sensitivity ◽  
Fetal Lung ◽  
Hydroxysteroid Dehydrogenase ◽  
Significant Activity ◽  
Fetal Kidney ◽  
Pulmonary Tissue ◽  
Fetal Sheep ◽  
Near Term ◽  
Ovine Fetal

Eleven-beta-hydroxysteroid dehydrogenase (11 beta-HSD) is an enzyme which degrades 11-hydroxycorticosteroids to biologically inactive 11-oxocorticosteroids (cortisone and 11-dehydrocorticosterone). In some tissues, the activity of this enzyme prevents binding of cortisol to mineralocorticoid receptors. The present experiments were designed to test the hypothesis that the fetal kidney contains 11 beta-HSD, that the activity of 11 beta-HSD in fetal kidney increases near term, and that the fetal lung does not contain significant 11 beta-HSD activity. In kidney and lung tissue from 23 fetal sheep ranging in age between 86 and 145 days' gestation, we measured 11 beta-HSD activity. We found significant activity in fetal kidney (14-85% conversion from cortisol to cortisone) but no measurable activity in fetal lung (0-9%). The activity of 11 beta-HSD was significantly related to fetal gestational age (r = 0.76, n = 14). We conclude that 11 beta-HSD activity in the fetal kidney develops as a function of fetal gestational age, and that activity cannot be demonstrated in fetal lung. We speculate 11 beta-HSD in the fetus might function to alter the sensitivity of target organs to glucocorticoids, as well as to mineralocorticoids, and that the absence of activity in the lung allows a high sensitivity of pulmonary tissue to cortisol at the end of gestation.

Opposite effects of glucocorticoid on hepatic 11 β-hydroxysteroid dehydrogenase mRNA and activity in fetal and adult sheep

1994 ◽  
Vol 143 (1) ◽  
pp. 121-126 ◽  
Author(s):  
K Yang ◽  
E T M Berdusco ◽  
J R G Challis
Keyword(s):  
Gene Expression ◽  
Fetal Liver ◽  
Reductase Activity ◽  
Mrna Level ◽  
Hydroxysteroid Dehydrogenase ◽  
Fetal Life ◽  
Mrna Levels ◽  
Fetal Sheep ◽  
Adult Sheep ◽  
Hepatic Level

Abstract The level of 11 β-hydroxysteroid dehydrogenase (11β-HSD) mRNA in the fetal sheep liver increases dramatically between day 130 and term (term=day 145), but the causal factors remain unknown. The present study was designed to determine the effects of exogenous glucocorticoid on the fetal hepatic 11 β-HSD gene expression. Dexamethasone (dex; 2 μg/min over 15 min every 2 h) or saline was infused into chronically-catheterized fetal sheep at day 130 of gestation for 4 days. At the end of infusion, the lower right lobe of the liver was collected, total cellular RNA extracted and subjected to Northern blot analysis. It was found that the level of the hepatic 11 β-HSD mRNA in dex-treated fetuses was about four times higher than that in the saline-treated controls. To examine whether changes occur in the response of hepatic 11 β-HSD gene expression to glucocorticoids in adulthood, we also treated non-pregnant ewes with dex (10 mg/day) for 4 days. By contrast, this treatment regime in adult sheep produced a small but significant decrease in hepatic 11 β-HSD mRNA levels. We also determined whether age-specific changes in the hepatic level of 11 β-HSD mRNA following dex treatment were reflected in the level of 11 β-HSD enzyme activity. Hepatic 11 β-HSD activity was determined by a standard in vitro conversion assay using cortisol and cortisone as physiological substrates. In both fetal and adult livers, 11-oxoreductase activity (cortisone→cortisol) was predominant. Following dex treatment, there was a significant increase in the fetal hepatic level of both 11β-dehydrogenase (cortisol→cortisone) and 11-oxoreductase activities. Furthermore, the C-11 activation index, an indicator of glucocorticoid net gain, was also increased in the fetal liver by dex. In marked contrast, dex treatment in the adult did not alter the C-11 activation index though it produced a significant decrease in the hepatic level of both 11 β-dehydrogenase and reductase activities. In summary, these results indicate that (1) exogenous glucocorticoid exerts opposite effects on hepatic 11 β-HSD gene expression in fetal and adult sheep; (2) dex-induced age-specific changes in the level of 11β-HSD mRNA are carried though to the level of 11β-HSD protein; and (3) since 11 β-HSD reductase activity is predominant in both fetal and adult sheep livers, the liver may be a potential extra-adrenal source of cortisol. Furthermore, we speculate that (1) the dramatic increase in the fetal hepatic 11 β-HSD mRNA level at term may be due to the elevated fetal plasma concentration of glucocorticoid; and (2) glucocorticoid-induced increases in the fetal hepatic 11β-HSD gene expression and the resultant increase in the C-11 activation index during the last days of fetal life may play a crucial role in fetal organ maturation and in the endocrine mechanisms leading to parturition. Journal of Endocrinology (1994) 143, 121–126

'Liver-type' 11β-hydroxysteroid dehydrogenase cDNA encodes reductase but not dehydrogenase activity in intact mammalian COS-7 cells

1994 ◽  
Vol 13 (2) ◽  
pp. 167-174 ◽  
Author(s):  
S C Low ◽  
K E Chapman ◽  
C R W Edwards ◽  
J R Seckl
Keyword(s):  
Dehydrogenase Activity ◽  
Rat Liver ◽  
Mammalian Cells ◽  
Reductase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Luciferase Reporter ◽  
Luciferase Expression ◽  
Intact Cells ◽  
Mmtv Ltr

ABSTRACT 11β-Hydroxysteroid dehydrogenase (11β-HSD) catalyses the metabolism of corticosterone to inert 11-dehydrocorticosterone, thus preventing glucocorticoid access to otherwise non-selective renal mineralocorticoid receptors (MRs), producing aldosterone selectivity in vivo. At least two isoforms of 11β-HSD exist. One isoform (11β-HSD1) has been purified from rat liver and an encoding cDNA cloned from a rat liver library. Transfection of rat 11β-HSD1 cDNA into amphibian cells with a mineralocorticoid phenotype encodes 11 β-reductase activity (activation of inert 11-dehydrocorticosterone) suggesting that 11β-HSD1 does not have the necessary properties to protect renal MRs from exposure to glucocorticoids. This function is likely to reside in a second 11β-HSD isoform. 11β-HSD1 is co-localized with glucocorticoid receptors (GRs) and may modulate glucocorticoid access to this receptor type. To examine the predominant direction of 11β-HSD1 activity in intact mammalian cells, and the possible role of 11β-HSD in regulating glucocorticoid access to GRs, we transfected rat 11β-HSD1 cDNA into a mammalian kidney-derived cell system (COS-7) which has little endogenous 11β-HSD activity or mRNA expression. Homogenates of COS-7 cells transfected with increasing amounts of 11β-HSD cDNA exhibited a dose-related increase in 11 β-dehydrogenase activity. In contrast, intact cells did not convert corticosterone to 11-dehydrocorticosterone over 24 h, but showed a clear dose-related 11β-reductase activity, apparent within 4 h of addition of 11-dehydrocorticosterone to the medium. To demonstrate that this reflected a change in functional intracellular glucocorticoids, COS-7 cells were co-transfected with an expression vector encoding GR and a glucocorticoid-inducible MMTV-LTR luciferase reporter construct, with or without 11β-HSD. Corticosterone induced MMTV-LTR luciferase expression in the presence or absence of 11β-HSD. 11-Dehydrocorticosterone was without activity in the absence of 11β-HSD, but induced MMTV-LTR luciferase activity in the presence of 11β-HSD. These results indicate that rat 11β-HSD1 can behave exclusively as a reductase in intact mammalian cells. Thus in some tissues in vivo, 11β-HSD1 may regulate ligand access to GRs by reactivating inert glucocorticoids.

Gestational changes in fetal renal and hepatic angiotensinogen mRNA and protein

1998 ◽  
Vol 10 (5) ◽  
pp. 399 ◽  
Author(s):  
David Y. Zhang ◽  
Eugenie R. Lumbers ◽  
June J. Wu
Keyword(s):  
Fetal Liver ◽  
Rnase Protection Assay ◽  
Protein Product ◽  
Late Gestation ◽  
Protection Assay ◽  
Rnase Protection ◽  
Fetal Sheep ◽  
Protein Levels ◽  
Adult Kidney ◽  
Liver And Kidney

The aim of the study was to determine the amount of angiotensinogen expression and its protein product in fetal sheep liver and kidney in the last third of gestation. Angiotensinogen mRNA was measured by RNase protection assay and its protein levels were measured by radioimmunoassay. Levels were measured at 80, 95, 111, 125 and 139 days. Angiotensinogen mRNA was present in all fetal liver and kidney samples tested. The ratio of hepatic angiotensinogen mRNA/18 S rRNA increased by 100% (P<0.001) and angiotensinogen levels increased by 33% (P<0.001) in fetal sheep from 80 to 139 d. Over the same period the ratio of renal angiotensinogen mRNA/18 S rRNA increased by 170% (P<0.001) and renal angiotensinogen protein increased by 41% (P<0.001). The levels of angiotensinogen mRNA and its protein in the adult kidney were less than in kidneys of 139 d old fetuses (P<0.01). There was a direct relationship between levels of angiotensinogen mRNA and its protein in the liver (r = 0.53, P<0.01, n = 25) and in the kidney (r = 0.75, P<0.0001, n = 24). These findings demonstrate that there is a significant increase in both hepatic and renal angiotensinogen gene expression in the last third of gestation in the fetal sheep and that this increase is associated with an increase of angiotensinogen levels in both tissues. This increase in angiotensinogen in late gestation could influence the activity of both the intrarenal and circulating renin angiotensin systems.

scholarly journals Effects of cortisol and oestradiol on hepatic 11beta-hydroxysteroid dehydrogenase type 1 and glucocorticoid receptor proteins in late-gestation sheep fetus

2003 ◽  
Vol 176 (2) ◽  
pp. 175-184 ◽  
Author(s):  
S Gupta ◽  
N Alfaidy ◽  
AC Holloway ◽  
WL Whittle ◽  
SJ Lye ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Fetal Liver ◽  
Reductase Activity ◽  
Plasma Concentrations ◽  
Hydroxysteroid Dehydrogenase ◽  
Late Gestation ◽  
Concurrent Administration ◽  
Fetal Plasma ◽  
Fetal Organ

In the late-gestation sheep, increased fetal plasma cortisol concentration and placental oestradiol (E(2)) output contribute to fetal organ maturation, in addition to the onset of parturition. Both cortisol and E(2) are believed to regulate the enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1), which interconverts bioactive 11-hydroxy glucocorticoids and their inactive 11-keto metabolites. 11beta-HSD1, abundantly expressed in fetal liver, operates primarily as a reductase enzyme to produce bioactive cortisol and thus regulates local hepatic glucocorticoid concentrations. Cortisol acts through the glucocorticoid receptor (GR) present in the liver. In this study, we examined the effects of cortisol and E(2) on hepatic 11beta-HSD1 and GR in the liver of chronically catheterized sheep fetuses treated with saline (n=5), cortisol (1.35 mg/h; n=5), saline+4-hydroxyandrostendione, a P450 aromatase inhibitor (4-OHA; 1.44 mg/h; n=5), or cortisol+4-OHA (n=5). Cortisol infusion resulted in increased plasma concentrations of fetal cortisol and E(2); concurrent administration of 4-OHA attenuated the increase in plasma E(2) concentrations. Using immunohistochemistry, we showed that fetal hepatocytes expressed both 11beta-HSD1 and GR proteins. Cortisol treatment increased GR in both cytosol and nuclei of hepatocytes; concurrent administration of 4-OHA was associated with distinct nuclear GR staining. Western blot revealed that cortisol, in the absence of increased E(2) concentrations, significantly increased concentrations of 11beta-HSD1 (34 kDa) and GR (95 kDa) proteins. 11beta-HSD1 enzyme activity was measured in the liver microsomal fraction in the presence of [(3)H]cortisone (10(-)(6) M) or [(3)H]cortisol (10(-)(6) M) and NADPH (reductase activity) or NADP(+) (dehydrogenase activity) respectively. 11beta-HSD1 reductase activity was significantly greater in the presence of cortisol. In summary, we found that, in sheep during late gestation, cortisol increased both 11beta-HSD1 and GR in the fetal liver, and these effects were accentuated in the absence of increased E(2).

EFFECTS OF TAMOXIFEN ON THE BINDING AND METABOLISM OF TESTOSTERONE BY HUMAN PROSTATIC TISSUE AND PLASMA IN VITRO

1979 ◽  
Vol 83 (3) ◽  
pp. 369-378 ◽  
Author(s):  
F. K. HABIB ◽  
G. RAFATI ◽  
M. R. G. ROBINSON ◽  
S. R. STITCH
Keyword(s):  
Dehydrogenase Activity ◽  
Reductase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Inhibitory Effect ◽  
Prostatic Tissue ◽  
Sex Hormone Binding Globulin ◽  
Benign Tissue ◽  
The Mean ◽  
Malignant Prostate

The in-vitro metabolism of testosterone in benign and malignant prostatic tissue was examined and distinct quantitative differences between the two types of specimens were observed. The major metabolite of testosterone in the hyperplastic prostate was 5α-dihydrotestosterone and a high 3α(β)-hydroxysteroid dehydrogenase activity was also detected. In the malignant tissue, 5α-reductase activity was considerably reduced and there was little or no androstanediol formed; the 17β-dehydrogenase activity was, however, higher than in the benign tissue. The decrease in 5α-reductase was always followed by a compensatory change in the 3α(β)-hydroxysteroid dehydrogenase of the malignant prostate. The present study revealed that the ratio of the mean activities of 5α-reductase to 3α(β)-hydroxysteroid dehydrogenase in the two types of specimen always remained a constant. Although the antioestrogen, tamoxifen, induced an inhibitory effect on the activities of 5α-reductase and 17β-hydroxysteroid dehydrogenase in the gland, the present investigation also suggested that tamoxifen stimulated the activity of 3α(3β)-hydroxysteroid dehydrogenase. In blood, the action of tamoxifen appeared to be confined to the displacement of androgens from the binding sites on the sex hormone binding globulin.

Effects of unilateral orchidectomy on rat epididymal Δ4-5α-reductase and 3α-hydroxysteroid dehydrogenase

1979 ◽  
Vol 57 (9) ◽  
pp. 998-1003 ◽  
Author(s):  
B. Robaire
Keyword(s):  
Luteinizing Hormone ◽  
Dehydrogenase Activity ◽  
Reductase Activity ◽  
Follicle Stimulating Hormone ◽  
Hydroxysteroid Dehydrogenase ◽  
Peripheral Circulation ◽  
Seminal Vesicles ◽  
Ventral Prostate ◽  
Metabolizing Enzymes ◽  
Adult Rat

The effects of unilateral orchidectomy on the adult rat epididymal testosterone metabolizing enzymes, Δ4-5α-reductase and α-hydroxysteroid dehydrogenase, are investigated. Five weeks following unilateral orchidectomy, it is found that the activity of 3α-hydroxysteroid dehydrogenase per organ is not altered, whereas Δ4-5α-reductase activity decreased by more than 80% on the side of the orchidectomy. Neither accessory sex tissue weights, ventral prostate and seminal vesicles, nor the concentration of circulating testosterone, luteinizing hormone, follicle-stimulating hormone, or prolactin is altered by unilateral orchidectomy. These data indicate that (1) epididymal 3α-hydroxysteroid dehydrogenase activity can be maintained by circulating androgens and that (2) the major factor regulating Δ4-5α-reductase activity is not a substance secreted by the testes into the peripheral circulation. It is suggested that a substance directly secreted into the epididymis by the testis regulates epididymal Δ4-5α-reductase activity.

The in vitro formation of sulfates and glucuronides of estrogens by adult and fetal ovine tissues

1985 ◽  
Vol 63 (8) ◽  
pp. 785-791 ◽  
Author(s):  
R. Hobkirk ◽  
Catherine A. Cardy
Keyword(s):  
High Speed ◽  
Fetal Liver ◽  
Kidney Cortex ◽  
Fetal Kidney ◽  
Experimental Conditions ◽  
Kidney Medulla ◽  
Estrone Sulfate ◽  
Sulfate Production ◽  
Pregnant Sheep ◽  
Liver And Kidney

Incubation of nanomolar concentrations of [3H]estrone with ovine liver slices from adult and fetal animals demonstrated, in particular, the production of estrogen sulfates together with smaller amounts of glucuronides, even although microsomal estrogen glucuronyltransferase (GT) and sulfatase activities were high, especially in adult tissue. [3H]Estriol was conjugated almost exclusively as sulfate under the same experimental conditions. Slices of maternal and fetal kidney medulla were also strikingly active in promoting estrogen sulfate production as were slices of fetal kidney cortex. Adult kidney cortex conjugated estrogen only in the glucuronide form. These data indicate the possibility that maternal and fetal liver and kidney might contribute to the high circulating level of estrone sulfate in the pregnant sheep. Through the use of [3H]estrone and [3H]estrone sulfate as substrates, it was possible to demonstrate that adult slices of kidney medulla possessed relatively low sulfatase, considerable sulfotransferase (ST), and virtually no GT activity, whereas cortex had high sulfatase, little or no ST, and low, though demonstrable, GT activity. The ST activity of kidney high-speed supernatants was stimulated by the presence of sulfhydryl groups, whereas that in liver was not. Enzymic reduction of estrone and (or) estrone sulfate by liver and kidney slices indicated that, in the former, 17α-reduction prevailed and, in the latter with the exception of the maternal medulla, 17β-reduction was the main pathway, particularly in the fetus.

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