Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.15.1 (ACE)
18,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors evaluated the influence of NAD, NADP, G-6-P and G-6-PDH on the synthesis of steroid hormones in the interstitial gland of the rat. The animals were killed by decapitation, and sections of the nucleus weighing altogether 20 mg were incubated with NAD (0.4 mM), NADP (0.4 mM), G-6-P (3.5 mM) and G-6-PDH (2 j.m./ml) for 4 hours in CO2 incubator. Then the tissue was homogenized, removed by centrifugation and then from the homogenous supernatant the authors extracted steroids which were in the incubating medium and in the tissue. Steroid hormones examined were marked radioimmunologically, they were: pregnenolon as the first and testosterone as the second stage of synthesis of nucleus androgens. The search carried out shows that the strongest stimulator in biosynthesis of pregnenolon was NADP together with the reducing system (G-6-P and G-6-PDH). On the other hand, in case of testosterone the highest effectiveness was achieved by simultaneous use of the cofactors examined. Applying cofactors separately the authors were able to find that both NAD and NADP together with the reducing system were responsible for testosterone synthesis and their simultaneous applying in the incubating medium leads to a synergistic effect.
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PMID:[The role of gonadotropins, cyclic AMP, 22-R-hydroxycholesterol and cofactors in regulating endocrine functions of the Leydig cells in rats. I. Effect of cofactors on the synthesis of steroid hormones in the interstitial gland of rats]. 263 80

Within the uterine glands, the following enzymes were demonstrated by histochemical methods after 30, 58, 80, 100, and 110 d of pregnancy, respectively: beta-N-acetyl-hexosaminidase, beta-galactosidase, beta-glucuronidase, alpha-mannosidase, acid phosphatase, alkaline phosphatase, esterases, cytochrome oxidase, 5-nucleotidase, leucine aminopeptidase, adenosine triphosphatase, diaphorases (NADH, NADPH), glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, succinate dehydrogenase, isocitrate dehydrogenase (NAD, NADP), beta-hydroxybutyrate dehydrogenase, glycero-3-phosphate dehydrogenase, NAD-glycero-3-phosphate dehydrogenase, glutamate dehydrogenase (NAD, NADP), lactate dehydrogenase. The results show that the activities of G-6-PDH, 6-PGDH, and cytochrome oxidase increase within secreting cells during the 2nd half of pregnancy. The activities of the other enzymes remained almost unchanged during the period of investigation. The description of our results distinguishes between gland neck, middle, and distal part of the secretory unit, respectively. In general, the enzyme activities are similar within the middle and distal gland segments, but lower in the epithelia of the neck region. The activity of dehydrogenases was medium to intensive within the middle and distal gland segments, but only low to medium within the neck portion. Of the hydrolases, the acid phosphatase, ATPase, leucine aminopeptidase, and beta-galactosidase demonstrated an intensive activity within activity secreting cells. The enzyme activities of the gland epithelia are compared with these of the uterine surface epithelia and the histochemical results are discussed in context with their significance in histiotrophic nutrition.
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PMID:[Enzyme histochemistry of the pig placenta. III. Histotopics of enzymes in the uterine epithelium]. 309 49

Phenylephrine, vasopressin and glucagon each increased the amount of active (dephospho) pyruvate dehydrogenase (PDHa) in isolated rat hepatocytes. Treatment with 4 beta-phorbol 12-myristate 13-acetate (PMA) opposed the increase in PDHa caused by both phenylephrine and glucagon, but had no effect on the response to vasopressin: PMA alone had no effect on PDHa. As PMA is known to prevent the phenylephrine-induced increase in cytoplasmic free Ca2+ concentration ([Ca2+]c) and to diminish the increase [Ca2+]c caused by glucagon, while having no effect on the ability of vasopressin to increase [Ca2+]c, these data are consistent with the notion that in intact cells an increase in [Ca2+]c results in an increase in the mitochondrial free Ca2+ concentration, which in turn leads to the activation of PDH. In the presence of 2.5 mM-Ca2+, glucagon caused an increase in NAD(P)H fluorescence in hepatocytes. This increase is taken to reflect an enhanced activity of mitochondrial dehydrogenases. PMA alone had no effect on NAD(P)H fluorescence; it did, however, compromise the increase produced by glucagon. When the extracellular free [Ca2+] was decreased to 0.2 microM, glucagon could still increase NAD(P)H fluorescence. Vasopressin also increased fluorescence under these conditions; however, if vasopressin was added after glucagon, no further increase in fluorescence was observed. Treatment of the cells with PMA resulted in a smaller increase in NAD(P)H fluorescence on addition of glucagon: the subsequent addition of vasopressin now caused a further increase in fluorescence. Changes in [Ca2+]c corresponding to the changes in NAD(P)H fluorescence were observed, again supporting the idea that [Ca2+]c indirectly regulates intramitochondrial dehydrogenase activity in intact cells. PMA alone had no effect on pyruvate kinase activity, and the phorbol ester did not prevent the inactivation caused by glucagon. The latter emphasizes the different mechanisms by which the hormone influences mitochondrial and cytoplasmic metabolism.
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PMID:The glucagon-induced activation of pyruvate dehydrogenase in hepatocytes is diminished by 4 beta-phorbol 12-myristate 13-acetate. A role for cytoplasmic Ca2+ in dehydrogenase regulation. 359 19

The quantitative assay of hexokinase (HK), phosphorylase, phosphofructokinase (PFK), glucose 6-phosphate dehydrogenase (G-6-PDH), glycerol 3-phosphate dehydrogenase (G-3 PDH) and lactate dehydrogenase (LDH) revealed that coxal muscles compared to hepatopancreas contained higher activities of all the enzymes investigated. It appears that the coxal muscles of the premolt field crab has carbohydrate-based fuel economy. The hepatopancreas is a rich source of lipid and very poor source of glycogen. The activity of G-6-PDH is moderately high in the hepatopancreas. It seems that in this lipogenic tissue conversion of G-6-P to triose phosphate occurs predominately via pentose-phosphate pathway thus generating NADPH for lipogenesis. The relative G-3PDH ad LDH activities in hepatopancreas and coxal muscles led us to believe that the reconversion of NAD from NADH in hepatopancreas nd muscle flexor is effected by glycerol 3-phosphate shuttle, whereas in muscle extensor it is achieved by both G-3PDH and LDH activities.
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PMID:Glycolytic enzymes in the premolt field crab Paratelphusa hydrodromus (Milne-Edwards) (Crustacea). 619 88

The paper presents the results of quantitative changes in the activity of some most important oxidative-reductive enzymes in lung carcinoma cells. The histo- and cytospectrophotometric studies were carried out on the operation material removed from 32 patient with lung carcinoma including 12 cases of squamous cell carcinoma, 12 cases of adenocarcinoma, 4 cases of undifferentiated large cell and 4 cases of undifferentiated small cell carcinoma. Statistically significant increases in the activity of G-6-PDH, NADP-D and LDH were observed in a decreasing degree of tumour differentiation with a simultaneous relative decrease in the activity of SDH, MDH NAD-D and alpha-GPDH. When the activity of oxidoreductases was compared in tumours having the structure of squamous cell carcinoma and adenocarcinoma, a higher activity of LDH, SDH and alpha-GPDH in squamous cell carcinoma and high activity of G-6-PDH and NADP-D in adenocarcinoma were observed. Statistically significant differences in the activity of carbohydrate metabolism enzymes in small cell carcinoma and other histological forms of lung cancer were found: a significant increase in G-6-PDH and LDH and relative decline in the activity of SDH and alpha-GPDH. In all the examined histological forms of lung cancer there was a complete agreement in the results of histo- and cytospectrophotometric examinations of the activity of the main oxidative-reductive enzymes.
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PMID:[Histocytospectrophotometric characteristics of lung cancer]. 625 7

Activity levels of 7-ethoxycoumarin O-deethylase (ED), aminopyrine N-demethylase (APD), p-nitroanisole O-demethylase (p-NAD) and glucose-6-phosphate dehydrogenase (G-6-PDH) were determined in incubation mixtures for the liver-microsomal assay (LMA) at time 0 and after 1 and 2 h incubation under conditions for mutagenic assay. The experiments were performed with S9 liver fractions from mice (induced with Na-phenobarbital and beta-naphthoflavone) and rats (induced with Aroclor 1254) with and without G-6-PDH in the incubation mixtures. In the absence of G-6-PDH the activities were significantly lower at time 0 in the mouse. The pattern of stability, however, was similar for the activities, with an increase of stability after 1 and 2 h of pre-incubation (an exception for p-NAD). Only ED activity showed a similar behaviour in the rat. No differences were present for APD and p-NAD activities at time 0 in the rat, but the enzyme stabilities were significantly decreased after 2 h of incubation (about 15% and 10% for APD and p-NAD respectively) in the absence of G-6-PDH. At time 0, the amounts of G-6-PDH differed between mouse and rat fractions; however, during the incubations for LMA they decreased by about 57% and 53% for the two species, respectively. In addition to the above biochemical results, the presence of exogenous G-6-PDH in the incubations for the mutagenic assay, significantly increased the mitotic gene conversion and mitotic crossing-over of dimethylnitrosamine (DMN) and AR2MNFN (a nitroimidazo[2,1-b]thiazole) in the D7 strain of Saccharomyces cerevisiae.
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PMID:NADPH-generating system: influence on microsomal mono-oxygenase stability during incubation for the liver-microsomal assay with rat and mouse S9 fractions. 639 64

In porcine interareolar placental epithelia, the following enzymes were demonstrated by histochemical methods after 30, 58, 80, 100, and 110 d of pregnancy, respectively: beta-N-acetylhexosaminidase, beta-galactosidase, beta-glucuronidase, alpha-mannosidase, acid phosphatase, alkaline phosphatase, nonspecific esterases, cytochrome oxidase, 5-nucleotidase, leucine aminopeptidase, adenosine triphosphatase, diaphorases (NADH, NADPH), glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, succinate dehydrogenase, isocitrate dehydrogenase (NAD, NADP), beta-hydroxybutyrate dehydrogenase, glycero-3-phosphate dehydrogenase, NAD-glycero-3-phosphate dehydrogenase, glutamate dehydrogenase (NAD, NADP), lactate dehydrogenase. The results show that most of the enzyme activities remained almost unchanged during the period of investigation. Only G-6-PDH and 6-PGDH activities increased within the uterine epithelium and nonspecific esterase activity within uterine as well as chorionic epithelia during the 2nd half of pregnancy. Within chorionic and uterine epithelia, hydrolases but not dehydrogenases demonstrated a higher activity at the bases of chorionic villi as compared to the apices and flanks of the latter. The action and influence of the demonstrated enzymes on metabolism, energy transfer, secretory, and resorptive activities of chorionic and uterine epithelia are discussed.
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PMID:[Enzyme histochemical studies of the swine placenta. Histoptics of enzymes in interareolar placental epithelia]. 643 35

The toxicity of acetaldehyde and age related changes on oxidoreductases in the liver, brain, kidney, and muscle of female albino rats (Wistar strain) were studied. The specific activities of lactate [LDH], isocitrate [ICDH (NAD/NADP)], succinate [SDH], malate [MDH], glutamate [GDH] and glucose-6-Phosphate [G-6-PDH] dehydrogenases were significantly increased as a function of age. However, acetaldehyde treatment significantly inhibited oxidoreductases in the tissue of 21, 90 and 180 day old rats. Liver enzymes of young (21 days) rats exhibited greater sensitivity to acetaldehyde toxicity. Similar inhibition of oxidoreductases in brain and kidney of adult (180 days) rats treated with acetaldehyde was observed. LDH and GDH as compared to other enzymes studied showed higher susceptibility to acetaldehyde toxicity. The differential sensitivity of tissues and inhibition of oxidoreductases by acetaldehyde as a function of age could be attributed to hypoxic conditions, energy crisis, and mitochondrial structural changes. The results suggest that acetaldehyde affects oxidation of glucose via HMP shunt pathway, glycolytic pathways and Krebs cycle resulting in the impairment of carbohydrate metabolism.
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PMID:Effect of acetaldehyde on oxidoreductases in tissues of rats at different ages. 898 13

The morphological and functional development of the interstitial gland was studied in crossbred ewe lambs (East Friesian x Black-Head Pleven breeds) first birth and then at 1, 2, 3, 4, 5, 5.5 and 6 months, as well as at 1 year in anestrous ewes. Histological and histochemical (AP, NAD.H2-tetrasole reductase, G-6-PDH and delta(5)-3 beta-hydroxysteroid dehydrogenase (delta(5)-3 beta-HSD)) methods and transmission electron microscopy (TEM) were applied while the FSH and LH levels were measured. There was an abundance of epithelial cell cords in newborn animals, while interstitial cells were scanty. Cortical and medullary epithelial cell cords occupied an essential place in the histogenesis of ovine ovarian structures. They were clearly expressed during the whole postnatal period of the development, and showed a species specificity. The development of the interstitial gland was correlated with changes in the gonadotropic hormones. A new population of interstitial glands appeared around puberty in a similar manner to the so-called 'puberty gland' in the testis and ovary of humans and other mammals. The results suggest that in these crossbred lambs, puberty was attained between the 3rd and 4th month, and sexual maturity and 5 to 6 months of age.
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PMID:The interstitial gland of ovary of ewes from birth to sexual maturity. 945 76

Angiotensin II (ANG II) has multiple effects on cardiovascular and renal cells, including vasoconstriction, cell growth, induction of proinflammatory cytokines, and profibrogenic actions. Recent studies provide evidence that ANG II could stimulate intracellular formation of reactive oxygen species (ROS) such as the superoxide anion (O2-). This ANG II-mediated ROS formation exhibits different kinetic and lower absolute concentrations than those traditionally observed during the respiratory burst of phagocytic cells, but it likely involves similar membrane-bound NAD(P)H-oxidases. Current evidence suggests that ANG II, through AT1-receptor activation, upregulates several subunits of this multienzyme complex, resulting in an increase in intracellular O2- concentration. ROS are involved in several signal pathways, and redox-sensitive transcriptional factors (AP-1, NF-kappaB) have been characterized. ANG II-induced ROS play a pivotal role in several pathophysiologic situations of vascular and renal cells such as hypertension, endothelial dysfunction, nitrate tolerance, atherosclerosis, and cellular remodeling. Although these perceptions suggest that drugs interfering with ANG II effects (ACE inhibitors, AT1 -receptor antagonist) may serve as antioxidants, preventing vascular and renal changes, the clinical studies are not so straightforward. In fact, only specific risk groups, such as patients with diabetes mellitus or renal insufficiency, may benefit from ACE inhibitors, whereas hard endpoints showed no advantage for ACE inhibitors in patients with essential hypertension.
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PMID:Free radical production and angiotensin. 1098 Nov 45


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