DEHYDROGENASES IN THE PREPUBERTAL RAT OVARY: A HISTOCHEMICAL STUDY OF Δ5-3β-HYDROXYSTEROID DEHYDROGENASE AND ENZYMES OF CARBOHYDRATE OXIDATION FOLLOWING OXYTHIAMINE TREATMENT

1973 ◽  
Vol 73 (4) ◽  
pp. 759-770 ◽  
Author(s):  
Jayasree Sen Gupta ◽  
Sudhansu K. Dey ◽  
C. Deb
Keyword(s):  
Histochemical Study ◽  
Succinic Dehydrogenase ◽  
Hydroxysteroid Dehydrogenase ◽  
Histochemical Demonstration ◽  
Pentose Phosphate ◽  
Diaphorase Activity ◽  
Rat Ovary ◽  
Prepubertal Rats ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Stimulation Of

ABSTRACT A histochemical study of the NAD- and NADP-linked dehydrogenases, Δ5-3β-hydroxysteroid dehydrogenase (Δ5-3β-ODH) and glucose-6-phosphate dehydrogenase (G-6-PD), and the corresponding tetrazolium reductases in prepubertal rat ovaries following the administration of oxythiamine HCl revealed diminution in the activities of the two dehydrogenases, while the NAD- and NADP-tetrazolium reductase activities remained unchanged. The same treatment resulted in stimulation of dihydrolipoic dehydrogenase (DLDH) and succinic dehydrogenase (SDH) activities in the ovarian tissues. Supplementary histochemical demonstration of Δ5-3β-OHD activity in phosphate buffer at pH 9.0 revealed a similar localization of the enzyme as that observed at pH 7.1 and which was free of the NAD-linked diaphorase activity. A diminution of this ovarian enzyme activity at this pH was also evident, following oxythiamine treatment. The results indicate a suppression of ovarian steroidogenesis in the prepubertal rats as a result of an alteration of the pentose phosphate pathway enzyme, G-6-PD, following treatment with oxythiamine HCl.

PENTOSE PHOSPHATE PATHWAY AND STEROIDOGENESIS IN THE IMMATURE RAT OVARY AFTER MALONATE TREATMENT

1972 ◽  
Vol 70 (4) ◽  
pp. 758-766 ◽  
Author(s):  
Sudhansu K. Dey ◽  
Jayasree Sen Gupta ◽  
Sulekha Ghosh ◽  
C. Deb
Keyword(s):  
Pentose Phosphate Pathway ◽  
Steroid Hormone ◽  
Succinic Dehydrogenase ◽  
Hydroxysteroid Dehydrogenase ◽  
Pentose Phosphate ◽  
Immature Rat ◽  
Hormone Synthesis ◽  
Rat Ovary ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Stimulation Of

ABSTRACT Suppression of succinic dehydrogenase (SDH) activity resulted in stimulation of glucose-6-phosphate dehydrogenase (G-6-PD) and Δ5-3β-hydroxysteroid dehydrogenase (Δ5-3β-OHD) activities in the immature rat ovary after malonate treatment. The same treatment also produced depletion in the ovarian ascorbic acid and elevation in cholesterol concentrations, together with increase in the ovarian and uterine weight. The results indicate that stimulation of ovarian steroidogenesis, resulting from accelerated pentose phosphate pathway in combination with increased concentration of cholesterol in the gland, is possibly due to a direct effect of malonate on the immature rat ovary. The rise in ovarian and uterine weights is not due to the decreased inactivation of oestrogen in the liver, but rather to stimulation of steroid hormone synthesis in the immature ovary following malonate administration.

Hexose-6-phosphate dehydrogenase in the endoplasmic reticulum

2010 ◽  
Vol 391 (1) ◽  
Author(s):  
Silvia Senesi ◽  
Miklos Csala ◽  
Paola Marcolongo ◽  
Rosella Fulceri ◽  
Jozsef Mandl ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Endoplasmic Reticulum ◽  
Pentose Phosphate Pathway ◽  
Hydroxysteroid Dehydrogenase ◽  
Pyridine Nucleotide ◽  
Pentose Phosphate ◽  
The Metabolic Syndrome ◽  
Glucose 6 Phosphate Dehydrogenase

Abstract Hexose-6-phosphate dehydrogenase (H6PD) is a luminal enzyme of the endoplasmic reticulum that is distinguished from cytosolic glucose-6-phosphate dehydrogenase by several features. H6PD converts glucose-6-phosphate and NADP+ to 6-phosphogluconate and NADPH, thereby catalyzing the first two reactions of the pentose-phosphate pathway. Because the endoplasmic reticulum has a separate pyridine nucleotide pool, H6PD provides NADPH for luminal reductases. One of these enzymes, 11β-hydroxysteroid dehydrogenase type 1 responsible for prereceptorial activation of glucocorticoids, has been the focus of much attention as a probable factor in the pathomechanism of several human diseases including insulin resistance and the metabolic syndrome. This review summarizes recent advances related to the functions of H6PD.

Effects of Adrenalectomy, Adrenalectomy–Ovariectomy, and Cortisol and Estrogen Therapies Upon Enzyme Activities in Lactating Rat Mammary Glands

1972 ◽  
Vol 50 (4) ◽  
pp. 366-376 ◽  
Author(s):  
G. O. Korsrud ◽  
R. L. Baldwin
Keyword(s):  
Pyruvate Kinase ◽  
Enzyme Activities ◽  
Secretory Cell ◽  
Succinic Dehydrogenase ◽  
Mammary Glands ◽  
Pentose Phosphate ◽  
Phosphogluconate Dehydrogenase ◽  
Udpglucose Pyrophosphorylase ◽  
Cleavage Enzyme ◽  
Glucose 6 Phosphate Dehydrogenase

The effects of adrenalectomy and adrenalectomy–ovariectomy on the 5th day of lactation followed by cortisol and estrogen therapies on enzyme activities in rat mammary glands were investigated. This stage of lactation was selected because mammary secretory cell proliferation is essentially complete at this time thereby enabling study of the effects of cortisol and estrogen on enzyme levels in a nonproliferating secretory cell population. Eighteen enzymes were selected for study on the bases of their respective roles in milk biosynthesis and carbohydrate and energy metabolism and/or on the basis of previous studies indicating that their activities increase during midlactation or are regulated, in part, by steroid hormones. After adrenalectomy on the 5th day of lactation, cortisol therapy was required for normal increases in the activities of succinic dehydrogenase, citrate cleavage enzyme, malic enzyme, UDPglucose pyrophosphorylase, UDPglucose 4-epimerase, and glucose-6-phosphate dehydrogenase. The activities of UDPglucose pyrophosphorylase and glucose-6-phosphate dehydrogenase were higher than normal in cortisol-treated animals. Cortisol therapy during the last 2 days of the experiment increased the activity of UDPglucose pyrophosphorylase and possibly citrate cleavage enzyme. The activities of α-glycerolphosphate dehydrogenase, phosphoglucomutase, 6-phosphogluconate dehydrogenase, pentose phosphate metabolizing ability, hexokinase, phosphofructokinase, fructose-1,6-diphosphate aldolase, pyruvate kinase, lactic dehydrogenase, aspartate aminotransferase, isocitrate dehydrogenase, and extramitochondrial malate dehydrogenase were not notably affected by adrenalectomy or cortisol therapy. The activities of 6-phosphogluconate dehydrogenase, pentose phosphate metabolizing ability, phosphofructokinase, and pyruvate kinase may have increased after the 5th day of lactation in adrenalectomized as well as in normal animals. Combining ovariectomy with adrenalectomy reduced pup weight gains more than adrenalectomy alone, but did not further decrease significantly the activities of any of the enzymes measured. Ovariectomy had no effect when cortisol was administered. Cortisol therapy completely reversed adverse effects of estrogen given to adrenalectomized–ovariectomized animals. On the bases of these and previous data, it was concluded that cortisol regulates the rates of synthesis of several mammary gland enzymes during midlactation.

scholarly journals Minireview: Hexose-6-Phosphate Dehydrogenase and Redox Control of 11β-Hydroxysteroid Dehydrogenase Type 1 Activity

Endocrinology ◽  
2005 ◽  
Vol 146 (6) ◽  
pp. 2539-2543 ◽  
Author(s):  
Kylie N. Hewitt ◽  
Elizabeth A. Walker ◽  
Paul M. Stewart
Keyword(s):  
Reductase Activity ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Hydroxysteroid Dehydrogenase ◽  
Pentose Phosphate ◽  
Intact Cells ◽  
The Metabolic Syndrome ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
Glucose 6 Phosphate Dehydrogenase

Abstract Hexose-6-phosphate dehydrogenase (H6PDH) is a microsomal enzyme that is able to catalyze the first two reactions of an endoluminal pentose phosphate pathway, thereby generating reduced nicotinamide adenine dinucleotide phosphate (NADPH) within the endoplasmic reticulum. It is distinct from the cytosolic enzyme, glucose-6-phosphate dehydrogenase (G6PDH), using a separate pool of NAD(P)+ and capable of oxidizing several phosphorylated hexoses. It has been proposed to be a NADPH regenerating system for steroid hormone and drug metabolism, specifically in determining the set point of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) activity, the enzyme responsible for the activation and inactivation of glucocorticoids. 11β-HSD1 is a bidirectional enzyme, but in intact cells displays predominately oxo-reductase activity, a reaction requiring NADPH and leading to activation of glucocorticoids. However, in cellular homogenates or in purified preparations, 11β-HSD1 is exclusively a dehydrogenase. Because H6PDH and 11β-HSD1 are coexpressed in the inner microsomal compartment of cells, we hypothesized that H6PDH may provide 11β-HSD1 with NADPH, thus promoting oxo-reductase activity in vivo. Recently, several studies have confirmed this functional cooperation, indicating the importance of intracellular redox mechanisms for the prereceptor control of glucocorticoid availability. With the increased interest in 11β-HSD1 oxo-reductase activity in the pathogenesis and treatment of several human diseases including insulin resistance and the metabolic syndrome, H6PDH represents an additional novel candidate for intervention.

EFFECT OF SERUM GONADOTROPHIN ON DEHYDROGENASES OF THE CITRIC ACID CYCLE IN THE OVARY OF THE RAT

1963 ◽  
Vol 42 (4) ◽  
pp. 480-484 ◽  
Author(s):  
B. Eckstein ◽  
R. Landsberg
Keyword(s):  
Citric Acid ◽  
Citric Acid Cycle ◽  
Age Groups ◽  
Succinic Dehydrogenase ◽  
Immature Rat ◽  
Acid Cycle ◽  
Immature Rats ◽  
Rat Ovary

ABSTRACT The succinic, malic and isocitric dehydrogenases in the ovary of immature and mature, normal and serum gonadotrophin injected rats were examined. The Qo2 of these enzymes were markedly enhanced in the gonadotrophin injected rats of both age groups, except in the case of succinic dehydrogenase in the ovary of the immature rats, where a slight non-significant decrease was noted. It is concluded that in the mature rat ovary, gonadotrophin administration stimulates the activity of all the examined dehydrogenases of the citric acid cycle, whereas in the immature rat ovary, at least the isocitric- and malic dehydrogenases are thus stimulated.

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.

scholarly journals Metabolic Anti-Cancer Effects of Melatonin: Clinically Relevant Prospects

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 3018
Author(s):  
Marek Samec ◽  
Alena Liskova ◽  
Lenka Koklesova ◽  
Kevin Zhai ◽  
Elizabeth Varghese ◽  
...  
Keyword(s):  
Cancer Metabolism ◽  
Glucose Transporter ◽  
Aerobic Glycolysis ◽  
Cell Metabolism ◽  
Lactate Production ◽  
Pentose Phosphate ◽  
Metabolic Reprogramming ◽  
Effective Prevention ◽  
Anti Cancer ◽  
Glucose 6 Phosphate Dehydrogenase

Metabolic reprogramming characterized by alterations in nutrient uptake and critical molecular pathways associated with cancer cell metabolism represents a fundamental process of malignant transformation. Melatonin (N-acetyl-5-methoxytryptamine) is a hormone secreted by the pineal gland. Melatonin primarily regulates circadian rhythms but also exerts anti-inflammatory, anti-depressant, antioxidant and anti-tumor activities. Concerning cancer metabolism, melatonin displays significant anticancer effects via the regulation of key components of aerobic glycolysis, gluconeogenesis, the pentose phosphate pathway (PPP) and lipid metabolism. Melatonin treatment affects glucose transporter (GLUT) expression, glucose-6-phosphate dehydrogenase (G6PDH) activity, lactate production and other metabolic contributors. Moreover, melatonin modulates critical players in cancer development, such as HIF-1 and p53. Taken together, melatonin has notable anti-cancer effects at malignancy initiation, progression and metastasing. Further investigations of melatonin impacts relevant for cancer metabolism are expected to create innovative approaches supportive for the effective prevention and targeted therapy of cancers.

scholarly journals TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR) Is Upregulated in Lymphocytes Stimulated with Concanavalin A

2021 ◽  
Vol 22 (14) ◽  
pp. 7436
Author(s):  
Helga Simon-Molas ◽  
Xavier Vallvé-Martínez ◽  
Irene Caldera-Quevedo ◽  
Pere Fontova ◽  
Claudia Arnedo-Pac ◽  
...  
Keyword(s):  
Concanavalin A ◽  
Carbon Flux ◽  
Human Lymphocytes ◽  
Tumor Development ◽  
Pentose Phosphate ◽  
Akt Signaling Pathway ◽  
G6pdh Activity ◽  
Physiological Conditions ◽  
Glucose 6 Phosphate Dehydrogenase

The glycolytic modulator TP53-Inducible Glycolysis and Apoptosis Regulator (TIGAR) is overexpressed in several types of cancer and has a role in metabolic rewiring during tumor development. However, little is known about the role of this enzyme in proliferative tissues under physiological conditions. In the current work, we analysed the role of TIGAR in primary human lymphocytes stimulated with the mitotic agent Concanavalin A (ConA). We found that TIGAR expression was induced in stimulated lymphocytes through the PI3K/AKT pathway, since Akti-1/2 and LY294002 inhibitors prevented the upregulation of TIGAR in response to ConA. In addition, suppression of TIGAR expression by siRNA decreased the levels of the proliferative marker PCNA and increased cellular ROS levels. In this model, TIGAR was found to support the activity of glucose 6-phosphate dehydrogenase (G6PDH), the first enzyme of the pentose phosphate pathway (PPP), since the inhibition of TIGAR reduced G6PDH activity and increased autophagy. In conclusion, we demonstrate here that TIGAR is upregulated in stimulated human lymphocytes through the PI3K/AKT signaling pathway, which contributes to the redirection of the carbon flux to the PPP.

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