scholarly journals EFFECTS OF CHRONIC ADMINISTRATION AND SUBSEQUENT WITHDRAWAL OF ETHANOL-CONTAINING LIQUID DIET ON RAT LIVER TRYPTOPHAN PYRROLASE AND TRYPTOPHAN METABOLISM

1996 ◽  
Vol 31 (2) ◽  
pp. 205-215 ◽  
Author(s):  
S. BANO ◽  
R. G. ORETTI ◽  
C. J. MORGAN ◽  
A. A.-B. BADAWY ◽  
P. R. BUCKLAND ◽  
...  
Keyword(s):  
Rat Liver ◽  
Chronic Administration ◽  
Liquid Diet ◽  
Tryptophan Metabolism ◽  
Tryptophan Pyrrolase ◽  
Subsequent Withdrawal

scholarly journals The role of liver tryptophan pyrrolase in the opposite effects of chronic administration and subsequent withdrawal of drugs of dependence on rat brain tryptophan metabolism

1981 ◽  
Vol 196 (1) ◽  
pp. 161-170 ◽  
Author(s):  
A A Badawy ◽  
N F Punjani ◽  
M Evans
Keyword(s):  
Chronic Administration ◽  
Tryptophan Metabolism ◽  
Chronic Morphine ◽  
Drug Induced ◽  
Tryptophan Pyrrolase ◽  
Subsequent Withdrawal ◽  
Induced Changes ◽  
Phenazine Methosulphate ◽  
The Brain

1. Chronic administration of morphine, nicotine or phenobarbitone has previously been shown to inhibit rat liver tryptophan pyrrolase activity by increasing hepatic [NADPH], whereas subsequent withdrawal enhances pyrrolase activity by a hormonal-type mechanism. 2. It is now shown that this enhancement is associated with an increase in the concentration of serum corticosterone. 3. Chronic administration of the above drugs enhances, whereas subsequent withdrawal inhibits, brain 5-hydroxytryptamine synthesis. Under both conditions, tryptophan availability to the brain is altered in the appropriate direction. 4. The chronic drug-induced enhancement of brain tryptophan metabolism is reversed by phenazine methosulphate, whereas the withdrawal-induced inhibition is prevented by nicotinamide. 5. The chronic morphine-induced changes in liver [NADPH], pyrrolase activity, tryptophan availability to the brain and brain 5-hydroxytryptamine synthesis are all reversed by the opiate antagonist naloxone. 6. It is suggested that the opposite effects on brain tryptophan metabolism of chronic administration and subsequent withdrawal of the above drugs of dependence are mediated by the changes in liver tryptophan pyrrolase activity. 6. Similar conclusions based on similar findings have previously been made in relation to chronic administration and subsequent withdrawal of ethanol. These findings with all four drugs are briefly discussed in relation to previous work and the mechanism(s) of drug dependence.

scholarly journals The regulation of rat liver tryptophan pyrrolase activity by reduced nicotinamide-adenine dinucleotide (phosphate). Experiments with glucose and nicotinamide

1976 ◽  
Vol 156 (2) ◽  
pp. 381-390 ◽  
Author(s):  
A A B Badawy ◽  
M Evans
Keyword(s):  
Drinking Water ◽  
Rat Liver ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Chronic Administration ◽  
Glucose Effect ◽  
Tryptophan Pyrrolase ◽  
Subsequent Withdrawal ◽  
Phenazine Methosulphate

1. Chronic administration of glucose or nicotinamide in drinking water inhibits the activity of rat liver tryptophan pyrrolase, and subsequent withdrawal causes an enhancement. The enzyme activity is also inhibited by administration in drinking water of sucrose, but not fructose, which is capable of preventing the glucose effect. 2. The inhibition by glucose or nictinamide is not due to a defective apoenzyme synthesis nor a decreased cofactor availability. 3. The inhibition by nicotinamide is reversed by regeneration of liver NAD+ and NADP+ in vivo by administration of fructose, pyruvate or phenazine methosulphate. Inhibition by glucose is also reversed by the above agents and by NH4Cl. Reversal of inhibition by glucose or nicotinamide is also achieved in vitro by addition of NAD+ or NADP+. 4. Glucose or nicotinamide increases liver [NADPH]. [NADP+] is also increased by nicotinamide. [NADPH] is also increased by sucrose, but not by fructose, which prevents the glucose effect. Phenazine methosulphate prevents the increase in [NADPH] caused by both glucose and nicotinamide. 5. It is suggested that the inhibition of tryptophan pyrrolase activity by glucose or nicotinamide is mediated by both NADPH and NADH.

scholarly journals Prevention by pyrazole of the effects of chronic ethanol administration on the redox states of the hepatic nicotinamide–adenine dinucleotide (phosphate) couples and on liver and brain tryptophan metabolism in the rat

1979 ◽  
Vol 184 (1) ◽  
pp. 165-168 ◽  
Author(s):  
N F Punjani ◽  
A A B Badawy ◽  
M Evans
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Chronic Administration ◽  
Chronic Ethanol ◽  
Tryptophan Metabolism ◽  
Ethanol Administration ◽  
Redox States ◽  
Chronic Effects ◽  
Chronic Ethanol Administration ◽  
Tryptophan Pyrrolase

Chronic administration of pyrazole in the diet of rats does not cause toxicity and prevents the chronic effects of ethanol on: (1) the redox states of the hepatic NAD(P) couples; (2) liver tryptophan pyrrolase activity; (3) brain tryptophan and 5-hydroxytryptamine metabolism.

scholarly journals Tryptophan Metabolism in Rat Liver after Administration of Tryptophan, Kynurenine Metabolites, and Kynureninase Inhibitors

2016 ◽  
Vol 9 ◽  
pp. IJTR.S38190 ◽  
Author(s):  
Abdulla A.-B. Badawy ◽  
Samina Bano
Keyword(s):  
Rat Liver ◽  
Immune Activation ◽  
Kynurenic Acid ◽  
Chronic Administration ◽  
Kynurenine Pathway ◽  
Tryptophan Metabolism ◽  
Disease States ◽  
Metabolite Concentrations ◽  
Hydroxyanthranilic Acid ◽  
Stimulation Of

Rat liver tryptophan (Trp), kynurenine pathway metabolites, and enzymes deduced from product/substrate ratios were assessed following acute and/or chronic administration of kynurenic acid (KA), 3-hydroxykynurenine (3-HK), 3-hydroxyanthranilic acid (3-HAA), Trp, and the kynureninase inhibitors benserazide (BSZ) and carbidopa (CBD). KA activated Trp 2,3-dioxygenase (TDO), possibly by increasing liver 3-HAA, but inhibited kynurenine aminotransferase (KAT) and kynureninase activities with 3-HK as substrate. 3-HK inhibited kynureninase activity from 3-HK. 3-HAA stimulated TDO, but inhibited kynureninase activity from K and 3-HK. Trp (50 mg/kg) increased kynurenine metabolite concentrations and KAT from K, and exerted a temporary stimulation of TDO. The kynureninase inhibitors BSZ and CBD also inhibited KAT, but stimulated TDO. BSZ abolished or strongly inhibited the Trp-induced increases in liver Trp and kynurenine metabolites. The potential effects of these changes in conditions of immune activation, schizophrenia, and other disease states are discussed.

scholarly journals The effects of acute and chronic nicotine hydrogen (+)-tartrate administration and subsequent withdrawal on rat liver tryptophan pyrrolase activity and their comparison with those of morphine, phenobarbitone and ethanol

1975 ◽  
Vol 148 (3) ◽  
pp. 425-432 ◽  
Author(s):  
A A Badawy ◽  
M Evans
Keyword(s):  
Rat Liver ◽  
Acute Administration ◽  
Nicotine Treatment ◽  
Chronic Nicotine ◽  
Nicotine Administration ◽  
Hormonal Mechanism ◽  
Tryptophan Pyrrolase ◽  
Subsequent Withdrawal

Acute administration of nicotine hydrogen (+)-tartrate enhances the activity of rat liver tryptophan pyrrolase by a hormonal mechanism. Chronic nicotine treatment inhibits, and subsequent withdrawal enhances, the pyrrolase activity. The inhibition during chronic treatment is not due to a defective apoenzyme synthesis nor a decreased cofactor availability. Regeneration of liver NADP+ in vitro and in vivo reverses the inhibition. Chronic nicotine administration increases the liver NADPH concentration. The above effects of nicotine resemble to a remarkable degree those previously shown for morphine, phenobarbitone and ethanol. All effects are compared, and their possible significance in relation to drug dependence is discussed.

scholarly journals The effects of chronic phenobarbitone administration and subsequent withdrawal on the activity of rat liver tryptophan pyrrolase and their resemblance to those of ethanol

1973 ◽  
Vol 135 (3) ◽  
pp. 555-557 ◽  
Author(s):  
Abdulla A.-B. Badawy ◽  
Myrddin Evans
Keyword(s):  
Enzyme Activity ◽  
Rat Liver ◽  
Chronic Ethanol ◽  
Ethanol Administration ◽  
Ethanol Inhibition ◽  
Chronic Ethanol Administration ◽  
Tryptophan Pyrrolase ◽  
Subsequent Withdrawal

Chronic phenobarbitone administration inhibits the apo-(tryptophan pyrrolase) activity in homogenates of rat liver and subsequent withdrawal enhances the enzyme activity by 2.5-fold. Similar effects have been previously produced by chronic ethanol administration and withdrawal, but, whereas NADH may cause the ethanol inhibition, that by phenobarbitone may be mediated by NADPH.

scholarly journals Effect of Cytoplasmic Particles on Tryptophan Pyrrolase Activity of Rat Liver

1966 ◽  
Vol 241 (2) ◽  
pp. 304-308
Author(s):  
Olga Greengard ◽  
N. Mendelsohn ◽  
G. Acs
Keyword(s):  
Rat Liver ◽  
Tryptophan Pyrrolase

Glucocorticoid effects on respiration and metabolism by rat liver homogenates

1962 ◽  
Vol 202 (2) ◽  
pp. 343-346 ◽  
Author(s):  
Dennis D. Goetsch ◽  
L. E. McDonald
Keyword(s):  
Lactic Acid ◽  
Oxygen Uptake ◽  
Rat Liver ◽  
Inorganic Phosphate ◽  
Chronic Administration ◽  
Glucocorticoid Treatment ◽  
Carbohydrate Utilization ◽  
Protein Levels ◽  
Liver Homogenates ◽  
And Control

The effects of glucocorticoid administration on oxygen uptake, glucose and glycogen disappearance, lactic acid formation, and inorganic phosphate and protein levels in rat liver homogenates have been studied. A single injection of hydrocortisone, prednisolone, or 9 α-fluoroprednisolone 5 hr before sacrifice resulted in a highly significant increase in oxygen uptake by rat liver homogenates, whereas chronic administration of prednisolone daily for 7 days caused a marked inhibition in homogenate respiration. Glycolytic rate did not appear to be affected by single injections since endogenous carbohydrate utilization was similar in liver homogenates prepared from control and treated animals. Incubation of liver homogenates under aerobic conditions disclosed that inorganic phosphate levels were decreased in homogenates from corticoid-treated rats, whereas these levels were similar in treated and control liver homogenates incubated under nitrogen. Under anaerobic conditions, liver homogenates from treated rats accumulated lactic acid more rapidly than untreated liver homogenates. Glucocorticoid treatment did not appear to affect protein disappearance since no differences between protein levels in treated and untreated rat liver homogenates were detected following incubation.

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