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:1.1.1.1 (alcohol dehydrogenase)
9,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acute ethanol administration significantly increased the concentration of adenosine monophosphate (5'-AMP) in the intact freeze-clamped rat liver regardless of the ethanol dose administered. The increase was abolished by the alcohol dehydrogenase inhibitor 4-methylpyrazole, but was also seen after direct infusion of acetaldehyde into the portal vein. Administration of acetate to give hepatic levels similar to those seen during ethanol oxidation failed, however, to cause an increase in AMP. After ethanol administration there was a highly significant positive correlation between individual AMP levels and 3-OH-butyrate/acetoacetate ratios. The results suggest that the increase in liver AMP reflects activation of ethanol-derived acetate by acetothiokinase in the mitochondrial matrix. Ethanol, but not acetate inhibits the citric acid cycle, as reflected by the shift in the mitochondrial redox state. This could inhibit production of GTP needed for AMP phosphorylation by GTP-AMP phosphotransferase, thus explaining the accumulation of AMP by ethanol.
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PMID:Elevation by ethanol and its metabolites of liver adenosine monophosphate. 396 39

Treatment of the serosal surface of the isolated bladders of toads (Bufo marinus) with phospholipase C inhibited the hydro-osmotic response to ADH, but did not prevent the rise in cyclic AMP concentrations associated with hormone action.
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PMID:Increased concentrations of cyclic 3',5'-adenosine monophosphate without a physiological response after antidiuretic hormone. 433 88

The physiological basis for the polyuria and polydipsia occurring in some manic-depressive patients treated with lithium salts was studied in vivo and in vitro. Three lithium-treated polyuric patients, in whom other causes of a concentrating defect were excluded, had abnormal urinary concentrating abilities after a standard water depreviation test. Two of these patients failed to respond to exogenous vasopressin (ADH) and one had a subnormal response. The abilities of these patients to excrete solute-free water (C(H2O)) was comparable to normal subjects during steady-state water diuresis, suggesting no gross abnormalities in sodium transport. However, each of these patients demonstrated abnormally low capacities to reabsorb solute-free water (T(C) (H2O)) under hydropenic conditions after administration of hypertonic saline and vasopressin. These in vivo findings demonstrate at least a nephrogenic basis for the diabetes insipidus syndrome manifested by these three patients. The defect in water transport was further characterized in toad urinary bladders in vitro. Short-circuit current (I) and water flow (W) were studied under basal, ADH-stimulated, and cyclic adenosine 3',5'-monophosphate (c-AMP)-stimulated conditions. Increasing mucosal [Li(+)] progressively inhibited basal I, and both I and W induced by ADH. Significant inhibition of basal and ADH-induced I was observed at mucosal [Li(+)] < 1.1 mEq/liter, and of ADH-induced W at mucosal [Li(+)] = 11 mEq/liter. On the other hand, at these lithium concentrations, neither c-AMP-stimulated W nor I was inhibited. Increasing serosal [Li(+)] produced significant inhibition of basal I only at [Li(+)] at least 50-fold greater than at the mucosal (urinary) surface. These in vitro studies confirm that mucosal lithium inhibits the action of ADH, but not c-AMP. Hence, lithium appears to be a significant inhibitor of ADH-stimulated water flow, probably acts from the urinary surface, and appears to exert its effect at a site biochemically proximal to c-AMP action.
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PMID:Lithium-induced nephrogenic diabetes insipidus: in vivo and in vitro studies. 434 1

Commercially available crystalline yeast alcohol dehydrogenase contained protein kinase activity. Casein and phosvitin were readily phosphorylated, but whole calf thymus histone was not. The protein kinase activity was inhibited by KCl, was not stimulated by cyclic AMP and could be separated from the alcohol dehydrogenase activity by sucrose density centrifugation.
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PMID:Protein kinase activity in commercially available crystalline yeast alcohol dehydrogenase. 435 9

1. The disappearance of pyridine nucleotides during incubation with mosquito homogenates proceeds through the hydrolysis of the pyrophosphate linkage of these compounds as demonstrated by the formation of NMN and AMP from NAD(+). This reaction was also demonstrated by the loss in the coenzyme functioning property of NAD(+) (yeast alcohol dehydrogenase reaction) without a concomitant loss in reactivity towards cyanide. Transglycosidase activity was not observed in the mosquito homogenates, and low concentrations of nicotinamide did not inhibit the NAD(+) splitting activity of these homogenates. These observations are all in accord with the presence in these homogenates of a NAD(+) pyrophosphatase rather than a NADase. 2. The NAD(+) pyrophosphatase is destroyed by boiling, is not heat-activated, and has a pH optimum at pH8.75. In addition to NAD(+), other dinucleotides such as NADP(+), the 3-acetylpyridine and thionicotinamide analogues of NAD(+) and the thionicotinamide analogue of NADP(+), function as substrates in the hydrolysis catalysed by the pyrophosphatase. 3. A decrease in the specific activity of NAD(+) pyrophosphatase was observed during larval development, and a barely detectable activity was found in the pupa and adult. 4. Enzyme activity per organism increased in the larva but decreased to a very low value in the pupa and adult. These results indicate that the decrease in specific activity was due to a decrease in enzyme concentration rather than an increase in amounts of protein.
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PMID:Nicotinamide-adenine dinucleotide pyrophosphatase in the growing and aging mosquito. 438 8

The chemical synthesis of adenosine(5') [alpha-thio]diphospho(5')ribofuranosyl-nicotinamide (NAD[S]) is described. The product occurs as a pair of diastereomers with different configuration at the sulfur-bearing phosphorus atom. The diastereomers were separated by high-performance liquid chromatography and their absolute configuration was determined after chemical degradation to the ADP[alpha S] diastereomers and chromatographic comparison with enzymically synthesized ADP[alpha S] diastereomers of known absolute configuration. Additional support for this assignment is based on different rates in the phosphodiesterase-catalyzed hydrolysis. Furthermore the synthesis of [14C]NAD[S] is described. The coenzyme activity of NAD[S] in the reaction with alcohol dehydrogenase from baker's yeast and lactate dehydrogenase from pig heart is very similar to that of beta-NAD. Also, NAD and NAD[S] serve equally well as substrates for NAD glycohydrolase from calf spleen. In contrast, no reaction was detected with NAD pyrophosphorylase, and hydrolysis of the separated NAD[S] diastereomers with snake venom phosphodiesterase showed a 26-fold and a 33-fold slower reaction rate than that of NAD. Nucleotide pyrophosphatase was less sensitive to the S substitution, hydrolyzing NAD[S] 14-times slower than NAD. Poly(ADP-ribose) polymerase from Ehrlich ascites tumor cell nuclei accepted NAD[S] as a substrate but the reaction was significantly slower and approached saturation at much lower values than with NAD. Alkaline hydrolysis of the products insoluble in trichloroacetic acid yielded AMP[S] as the main derivative. It is concluded that with NAD[S] as a substrate the nuclear acceptors were nearly exclusively mono(ADP-ribosyl) ated .
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PMID:NAD[S], an NAD analogue with reduced susceptibility to phosphodiesterase. Chemical synthesis and enzymic properties. 614 44

2-Mercapto-1-(beta-4-pyridethyl) benzimidazole (MPB) was originally introduced as a reversible inhibitor of RNA synthesis, but subsequent findings made this suggestion doubtful. We examined the effect of MPB on active sodium transport, measured as short-circuit current (scc), across the isolated urinary bladder of the toad (Bufo marinus). The drug caused a rapid, dose-dependent inhibition of baseline scc; 25 micrograms/ml MPB reduced it by 70%. Sensitivity to MPB was the same in the presence and absence of metabolizable substrate. The transport stimulation by aldosterone (7 X 10(-8)M) was abolished entirely when MPB was introduced 30 min before the hormone. In bladders incubated with MPB with or without aldosterone, removal of both agents resulted in a rise in scc, which was more rapid in the aldosterone-pretreated hemibladders; a significant difference was observed after 30 min. This suggests that MPB inhibited transport at a site distal to messenger RNA accumulation. The effect of 3 hr of pretreatment with MPB on the response of the bladders to antidiuretic hormone (ADH, 20 mU) and cyclic AMP (cAMP, 10 mM) was then examined. The absolute increment in scc due to these agents was the same as in the absence of MPB, though the baseline was much reduced by the drug. After challenging MPB-pretreated bladders with theophylline (22.5 mM), sodium transport rose continuously for 90 min, in contrast to the small, short-lived rise in the absence of MPB. It is proposed that, in the toad bladder, MPB may: (1) inhibit cAMP-dependent protein kinase, as found by us in other tissues; and (2) counteract the accumulation of a transport inhibitor, possibly calcium or cyclic GMP, in tissues treated with endogenous or exogenous cAMP.
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PMID:2-Mercapto-1-(beta-4-pyridethyl) benzimidazole inhibition of basal and aldosterone-stimulated sodium transport but prolongation of the transient theophylline-induced stimulation in the toad bladder. 619 73

3 beta-Hydroxy-5-androsten-17-one is converted to 5-androstene-3, 17-dione by rat liver alcohol dehydrogenase (ADH). We have reported on the purity of the enzyme which is eluted with pyrazole as a single homogeneous protein using an AMP-agarose affinity column. Rat liver ADH can oxidize hydroxyl groups not only at 3 beta-, but also at 3 alpha-, and 17 beta-positions to a lesser extent; thus it is a pure mammalian enzyme with multifunctional activity for steroids. Since it does not contain delta 5-isomerase activity, the reaction of the dehydrogenase to form the delta 5-ketosteroid intermediate can be observed at pH 7.0, 25 degrees C. Similarly, intermediary product, 5-pregnene-3,20-dione, can be isolated in the conversion of pregnenolone by ADH to progesterone. With buffer alone in a cuvette, a non-enzymatic isomerization of the delta 5-3-ketone occurs at a slow rate (t 1/2 = 6 hrs) but occurs rapidly during isolation procedures. The delta 5-3-ketosteroid intermediates were identified by their behavior on TLC plates with UV light and by their characteristic spectra in the NMR.
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PMID:Formation and isolation of delta 5-3-ketosteroids using a purified rat liver alcohol dehydrogenase. 622 30

Angiotensin II (AII) and arginine vasopressin are capable of triggering glomerular mesangial cell contraction in vitro. A similar mechanism acting in vivo to reduce glomerular capillary surface area could account for the decline in the ultrafiltration coefficient (Kf)( that occurs in single glomeruli in response to infusion of these substances. Less clear is the mechanism whereby similar declines in Kf are induced with infusions of dibutyryl cyclic AMP (DBcAMP), parathyroid hormone (PTH), and prostaglandins, because PTH and PGE2, at least, are incapable of eliciting mesangial cell contraction in vitro. To further explore the factors that regulate Kf in vivo, we performed micropuncture experiments in 47 euvolemic Munich-Wistar rats. Infusions of DBcAMP, PTH, prostaglandins I2 and E2 led to lower mean values for plasma flow rate (QA) and Kf in superficial glomeruli than were found in animals given vehicle alone (control group), whereas average values for glomerular transcapillary hydraulic pressure difference (delta P) and total renal arteriolar resistance (RTA) tended to be higher. These increases in delta P and RTA, and decreases in QA and Kf, with DBcAMP, PTH, PGI2, and PGE2 are typical of changes induced by AII. Indeed, when saralasin, a competitive AII antagonist, was infused together with these various vasoactive substances, the effects on delta P, QA, RTA, and Kf were largely abolished. Therefore, the actions of DBcAMP, PTH, PGI2, and PGE2 on the glomerular microcirculation appear to depend on an intermediate action of AII. By contrast, although pitressin (ADH) infusion also led to a significant decline in Kf, saralasin administration did not reverse this change, suggesting that the action of ADH on the glomerular microcirculation is independent of a pathway involving AII. Based on these studies, it seems reasonable to propose that AII and ADH are both potentially important regulators of mesangial cell contraction, and thereby, glomerular capillary filtering surface area and Kf.
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PMID:Mechanisms of action of various hormones and vasoactive substances on glomerular ultrafiltration in the rat. 627 43

The effects of Tramadol-N2O-anaesthesia on the per- and postoperative change in blood concentrations of cortisol, prolactin, thyroxine, triiodothyronine, cyclic AMP, glucagon, antidiuretic hormone, PTH-peptide (44-68), glucose, lactate, pyruvate and free fatty acids (FFA) were investigated in connection with elective orthopaedic surgery. Anaesthesia in man with Tramadol and nitrous oxide were found to be associated with a significant elevation of plasma cortisol and plasma prolactin in man. However, cortisol secretion during anaesthesia is associated with an inhibition in T4-T3 conversion. No significant alterations in plasma glucagon concentrations were observed. Generally, surgical trauma induced a significant increase in plasma cyclic AMP with intraoperative levels between 26.4 and 34.3 pmol/ml. At the end of surgery a significant fall in plasma PTH-peptide (44-68) occurred. There was also a significant change in plasma ADH levels following induction of anaesthesia. During surgery we found plasma ADH levels up to 56 pg/ml. In addition stress and surgical trauma increased blood glucose and FFA while plasma pyruvate and plasma lactate nearly remained unchanged. The data would suggest that the non-specific stress response attributed to anaesthesia may in fact be reflecting a response to relatively light anaesthesia.
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PMID:[Endocrine reaction pattern in the course of a one-phase tramadol-N2O combination anesthesia]. 629 29


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