scholarly journals Hexose-6-Phosphate Dehydrogenase and 11β-Hydroxysteroid Dehydrogenase-1 Tissue Distribution in the Rat

Endocrinology ◽  
2007 ◽  
Vol 149 (2) ◽  
pp. 525-533 ◽  
Author(s):  
Elise P. Gomez-Sanchez ◽  
Damian G. Romero ◽  
Angela F. de Rodriguez ◽  
Mary P. Warden ◽  
Zygmunt Krozowski ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Dehydrogenase Activity ◽  
Leydig Cells ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Hydroxysteroid Dehydrogenase ◽  
Interstitial Cells ◽  
Rat Tissues ◽  
Rt Pcr ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
The Brain

Intracellular concentrations of the glucocorticoids cortisol and corticosterone are modulated by the enzymes 11β-hydroxysteroid dehydrogenase (11β-HSD) 1 and 2. 11β-HSD1 is a reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent microsomal reductase that converts the inactive glucocorticoids cortisone and 11-dehydrocorticosterone to their active forms, cortisol and corticosterone. Hexose-6-phosphate dehydrogenase (H6PDH) is an enzyme that generates NADPH from oxidized NADP (NADP+) within the endoplasmic reticulum. In the absence of NADPH or H6PDH to regenerate NADPH, 11β-HSD1 acts as a dehydrogenase and inactivates glucocorticoids, as does 11β-HSD2. A monoclonal antibody against H6PDH was produced to study the possibility that 11β-HSD1 in the absence of H6PDH may be responsible for hydroxysteroid dehydrogenase activity in tissues that do not express significant amounts of 11β-HSD2. H6PDH and 11β-HSD1 expression was surveyed in a variety of rat tissues by real-time RT-PCR, Western blot analysis, and immunohistochemistry. H6PDH was found in a wide variety of tissues, with the greatest concentrations in the liver, kidney, and Leydig cells. Although the brain as a whole did not express significant amounts of H6PDH, some neurons were clearly immunoreactive by immunohistochemistry. H6PDH was amply expressed in most tissues examined in which 11β-HSD1 was also expressed, with the notable exception of the renal interstitial cells, in which dehydrogenase activity by 11β-HSD1 probably moderates activation of the glucocorticoid receptor because rat renal interstitial cells do not have significant amounts of mineralocorticoid receptors. This antibody against the H6PDH should prove useful for further studies of enzyme activity requiring NADPH generation within the endoplasmic reticulum.

scholarly journals HISTOCHEMICAL DEMONSTRATION OF 3α-HYDROXYSTEROID DEHYDROGENASE ACTIVITY

1966 ◽  
Vol 14 (1) ◽  
pp. 77-83 ◽  
Author(s):  
KÁROLY BALOGH
Keyword(s):  
Leydig Cells ◽  
Hydroxysteroid Dehydrogenase ◽  
Histochemical Demonstration ◽  
Female Rats ◽  
Ventral Prostate ◽  
Tetrazolium Salt ◽  
Rat Tissues ◽  
Final Electron ◽  
Nucleotide Specificity ◽  
Final Electron Acceptor

The reversible oxidation of 3α-hydroxysteroids to their corresponding 3-keto forms comprises an important step in the metabolism of C19-steroids. The described techniquue demonstrates the activity of the enzyme catalyzing this reaction, with the use of androsterone as a substrate and a tetrazolium salt as the final electron acceptor. The enzyme is specific for 3α-hydroxysteroids; there was no histochemical reaction with epiandrosterone, the β isomer of androsterone. Since 3α-hydroxysteroid dehydrogenase is soluble in aqueous solutions, it was necessary to increase the osmolarity of the incubation medium by adding polyvinylpyrrolidone in a final concentration of 20%. Although the enzyme has a dual nucleotide specificity, no appreciable differences were seen in its distribution pattern in rat tissues with either NAD or NADP as a coenzyme. In adult female rats, enzyme activity was present in the liver, kidneys and clitoral glands. In mature males, diformazan deposits were observed in the liver, kidneys, preputiai glands, epididymis, ventral prostate and Leydig cells.

scholarly journals Identification of the Oxidative 3α-Hydroxysteroid Dehydrogenase Activity of Rat Leydig Cells as Type II Retinol Dehydrogenase*

Endocrinology ◽  
2000 ◽  
Vol 141 (5) ◽  
pp. 1608-1617 ◽  
Author(s):  
Dianne O. Hardy ◽  
Ren-Shan Ge ◽  
James F. Catterall ◽  
Yong-tai Hou ◽  
Trevor M. Penning ◽  
...  
Keyword(s):  
Dehydrogenase Activity ◽  
Leydig Cells ◽  
Hydroxysteroid Dehydrogenase ◽  
Type Ii ◽  
Retinol Dehydrogenase

scholarly journals 7-Oxysterols Modulate Glucocorticoid Activity in Adipocytes through Competition for 11β-Hydroxysteroid Dehydrogenase Type

Endocrinology ◽  
2008 ◽  
Vol 149 (12) ◽  
pp. 5909-5918 ◽  
Author(s):  
Malgorzata Wamil ◽  
Ruth Andrew ◽  
Karen E. Chapman ◽  
Jonathan Street ◽  
Nicholas M. Morton ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Reductase Activity ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Diabetes Type 2 ◽  
Selective Inhibition ◽  
Hydroxysteroid Dehydrogenase ◽  
Intracellular Enzyme ◽  
Increased Risk ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
Reaction Direction

Obesity is associated with an increased risk of diabetes type 2, dyslipidemia, and atherosclerosis. These cardiovascular and metabolic abnormalities are exacerbated by excessive dietary fat, particularly cholesterol and its metabolites. High adipose tissue glucocorticoid levels, generated by the intracellular enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), are also implicated in the pathogenesis of obesity, metabolic syndrome, and atherosclerosis. 11β-HSD1 also interconverts the atherogenic oxysterols 7-ketocholesterol (7KC) and 7β-hydroxycholesterol (7β-HC). Here, we report that 11β-HSD1 catalyzes the reduction of 7KC to 7β-HC in mature 3T3-L1 and 3T3-F442A adipocytes, leading to cellular accumulation of 7β-HC. Approximately 73% of added 7KC was reduced to 7β-HC within 24 h; this conversion was prevented by selective inhibition of 11β-HSD1. Oxysterol and glucocorticoid conversion by 11β-HSD1 was competitive and occurred with a physiologically relevant IC50 range of 450 nm for 7KC inhibition of glucocorticoid metabolism. Working as an inhibitor of 11β-reductase activity, 7KC decreased the regeneration of active glucocorticoid and limited the process of differentiation of 3T3-L1 preadipocytes. 7KC and 7β-HC did not activate liver X receptor in a transactivation assay, nor did they display intrinsic activation of the glucocorticoid receptor. However, when coincubated with glucocorticoid (10 nm), 7KC repressed, and 7β-HC enhanced, glucocorticoid receptor transcriptional activity. The effect of 7-oxysterols resulted from the modulation of 11β-HSD1 reaction direction, and could be ameliorated by overexpression of hexose 6-phosphate dehydrogenase, which supplies reduced nicotinamide adenine dinucleotide phosphate to 11β-HSD1. Thus, the activity and reaction direction of adipose 11β-HSD1 is altered under conditions of oxysterol excess, and could impact upon the pathophysiology of obesity and its complications.

HISTOCHEMICAL DEMONSTRATION OF 20β-HYDROXYSTEROID DEHYDROGENASE

1965 ◽  
Vol 32 (3) ◽  
pp. 337-339 ◽  
Author(s):  
A. H. BAILLIE ◽  
K. C. CALMAN ◽  
M. M. FERGUSON ◽  
D. McK. HART
Keyword(s):  
Dehydrogenase Activity ◽  
Leydig Cells ◽  
Hydroxysteroid Dehydrogenase ◽  
Histochemical Demonstration ◽  
Mouse Testis ◽  
Zona Fasciculata ◽  
Mouse Ovary ◽  
Theca Interna ◽  
Human And Mouse

SUMMARY NAD-dependent 20β-hydroxysteroid dehydrogenase activity can be demonstrated histochemically using Nitro-BT. 20β-Hydroxysteroid dehydrogenase activity was found in the Leydig cells of human and mouse testis, in the zona fasciculata of the mouse adrenal and in the theca interna of the mouse ovary.

scholarly journals The Glucose-6-Phosphate Transporter-Hexose-6-Phosphate Dehydrogenase-11β-Hydroxysteroid Dehydrogenase Type 1 System of the Adipose Tissue

Endocrinology ◽  
2007 ◽  
Vol 148 (5) ◽  
pp. 2487-2495 ◽  
Author(s):  
Paola Marcolongo ◽  
Simona Piccirella ◽  
Silvia Senesi ◽  
Livius Wunderlich ◽  
Isabelle Gerin ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Adipose Tissue ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Hydroxysteroid Dehydrogenase ◽  
Phosphate Transporter ◽  
Nicotinamide Adenine ◽  
Functional Connection ◽  
Pharmacological Targets ◽  
Isolated Adipocytes

11β-Hydroxysteroid dehydrogenase type 1, expressed mainly in the endoplasmic reticulum of adipocytes and hepatocytes, plays an important role in the prereceptorial activation of glucocorticoids. In liver endoplasmic reticulum-derived microsomal vesicles, nicotinamide adenine dinucleotide phosphate reduced supply to the enzyme is guaranteed by a tight functional connection with hexose-6-phosphate dehydrogenase and the glucose-6-phosphate transporter (G6PT). In adipose tissue, the proteins and their activities supporting the action of 11β-hydroxysteroid dehydrogenase type 1 have not been explored yet. Here we report the occurrence of the hexose-6-phosphate dehydrogenase in rat epididymal fat, as detected at the level of mRNA, protein, and activity. In the isolated microsomes, the activity was evident only on the permeabilization of the membrane because of the poor permeability to the cofactor nicotinamide adenine dineucleotide phosphate (NADP+), which is consistent with the intralumenal compartmentation of both the enzyme and a pool of pyridine nucleotides. In fat cells, the access of the substrate, glucose-6-phosphate to the intralumenal hexose-6-phosphate dehydrogenase appeared to be mediated by the liver-type G6PT. In fact, the G6PT expression was revealed at the level of mRNA and protein. Accordingly, the transport of glucose-6-phosphate was demonstrated in microsomal vesicles, and it was inhibited by S3483, a prototypic inhibitor of G6PT. Furthermore, isolated adipocytes produced cortisol on addition of cortisone, and the production was markedly inhibited by S3483. The results show that adipocytes are equipped with a functional G6PT-hexose-6-phosphate dehydrogenase-11β-hydroxysteroid dehydrogenase type 1 system and indicate that all three components are potential pharmacological targets for modulating local glucocorticoid activation.

scholarly journals CORRELATED MORPHOMETRIC AND BIOCHEMICAL STUDIES ON THE LIVER CELL

1969 ◽  
Vol 42 (1) ◽  
pp. 92-112 ◽  
Author(s):  
Willy Stäubli ◽  
Robert Hess ◽  
Ewald R. Weibel
Keyword(s):  
Endoplasmic Reticulum ◽  
Nicotinamide Adenine Dinucleotide ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Rat Hepatocytes ◽  
Dense Bodies ◽  
Biochemical Studies ◽  
Ploidy Pattern ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
Specific Number ◽  
Cytochrome P 450

The changes occurring in rat hepatocytes during a 5 day period of treatment with phenobarbital were determined by morphometric and biochemical methods, particular attention being paid to the endoplasmic reticulum. The hepatocytic cytoplasm played an overwhelming part in the liver hypertrophy, while the hepatocytic nuclei contributed to only a moderate extent. The endoplasmic reticulum accounted for more than half of the increase in cytoplasmic volume. The increase in the volume and number of hepatocytic nuclei in the course of phenobarbital treatment was associated with changes in the ploidy pattern. Until the 2nd day of treatment both the rough-surfaced endoplasmic reticulum (RER) and the smooth-surfaced endoplasmic reticulum (SER) participated in the increase in volume and surface of the whole endoplasmic reticulum (ER). Subsequently, the values for RER fell again to control levels, whereas those for SER continued to increase, with the result that by the 5th day of treatment the SER constituted the dominant cytoplasmic element. The specific volume of mitochondria and microbodies (peroxisomes) remained constant throughout the duration of the experiment, while that of the dense bodies increased. The specific number of mitochondria and microbodies displayed a significant increase, associated with a decrease in their mean volume. The phenobarbital-induced increase in the phospholipid and cytochrome P-450 content of the microsomes, as well as in the activities of microsomal reduced nicotinamide-adenine dinucleotide phosphate-cytochrome c reductase and N-demethylase, was correlated with the morphometric data on the endoplasmic reticulum.

Some histochemical and ultrastructural observations on the early foetal pig testis

Development ◽  
1986 ◽  
Vol 95 (1) ◽  
pp. 261-277
Author(s):  
C. J. A. H. V. van Vorstenbosch ◽  
C. M. J. E. van Rossum-Kok ◽  
B. Colenbrander ◽  
C. J. G. Wensing
Keyword(s):  
Endoplasmic Reticulum ◽  
Leydig Cell ◽  
Sertoli Cells ◽  
Leydig Cells ◽  
Tunica Albuginea ◽  
Hydroxysteroid Dehydrogenase ◽  
Mesenchymal Cells ◽  
Mitochondrial Complex ◽  
Sustentacular Cells

Testes of foetal pigs between 26 to 35 days post coitum (p.c.) were investigated histochemically and ultrastructurally. Diaphorase and Δ5-3β-hydroxysteroid dehydrogenase activities were studied using, respectively, NADH and pregnenolone and dihydroxy androsterone as substrates. Ultrastructurally, attention was focused on the development of mesenchymal cells and on the sustentacular cells in the primitive sex cords in an attempt to detect the origin of Ley dig cells. Histochemically there is a concentration of activity toward the interstitium with increasing age. Also the reactions increase in intensity. Ultrastructurally no evidence for Leydig cell development from Sertoli cells could be observed. Mesenchymal cells between the sex cords show a development toward Leydig cells. This is absent in mesenchymal cells in the future tunica albuginea. Before 30 days p.c. no ‘true’ Leydig cells can be observed morphologically. The role of the rough endoplasmic reticulum/mitochondrial complex, which is present in many mesenchymal and sustentacular cells, is discussed.

Naltrexone Normalizes the Suppression but not the Surge of Δ5-3β-Hydroxysteroid Dehydrogenase Activity in Leydig Cells of Stressed Rat Fetuses*

Endocrinology ◽  
1990 ◽  
Vol 127 (1) ◽  
pp. 88-92 ◽  
Author(s):  
INGEBORG L. WARD ◽  
O. BYRON WARD ◽  
O. BYRON HAYDEN ◽  
JUDITH WEISZ ◽  
JOANNE M. ORTH
Keyword(s):  
Dehydrogenase Activity ◽  
Leydig Cells ◽  
Hydroxysteroid Dehydrogenase ◽  
Rat Fetuses
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