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J G Joly

Publications and source records attributed to J G Joly.

16 recordsLinked to original sources
PubMed1988

Effects of chronic acetone administration on ethanol-inducible monooxygenase activities in the rat.

Liver microsomal monooxygenase activities known to be ethanol-inducible were determined in female Sprague-Dawley rats after 2-week treatment with 1% (v/v) acetone. Daily acetone intake was in the order of 1.2 g/kg. The final body weight, liver weight and microsomal protein content of acetone-treated rats were identical to those of untreated controls. Microsomal NADPH-cytochrome c reductase activity was also unaffected, while cytochrome P-450 content was only increased 12-18%. Ethanol-inducible p-nitrophenol hydroxylation, aniline hydroxylation and 7-ethoxycoumarin O-deethylation activities were enhanced 5.3-, 4.4- and 2.6-fold, respectively, by chronic acetone treatment. The sex-dependent inducing effect of ethanol on benzphetamine N-demethylation activity in female rats was not observed however, after acetone. Addition of acetone in vitro had a stimulatory effect on aniline hydroxylation by microsomes from control and acetone-induced rats. Acetone, however, was found to be a competitive inhibitor of p-nitrophenol hydroxylation activity (apparent Ki = 1.8 mM), an observation suggesting that p-nitrophenol is a more selective substrate than aniline for rat liver ethanol- and acetone-inducible cytochrome P-450j. Interruption of the chronic acetone treatment for 24 hr resulted in the almost complete disappearance of its inducing affects, this treatment apparently reproducing only the rapidly reversible preferential inducing effects of chronic ethanol administration. This experimental model of induction by acetone in the rat, when compared to chronic ethanol administration, would thus permit a more selective look at the consequences of these common inducing effects in particular, with respect to drug metabolism and toxicity in vivo, and this, in the absence of the hepatotoxic effects of ethanol itself.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1979

Multiplicity of induction patterns of rat liver microsomal mono-oxygenases and other polypeptides produced by administration of various xenobiotics.

Induction of hepatic microsomal mono-oxygenase species after administration of various xenobiotics is a well-documented phenomenon. To examine the number and specific species of rat liver microsomal membrane polypeptides involved in such responses, we have used sodium dodecyl sulphate/polyacrylamide-gel electrophoresis to analyse microsomal fractions from animals treated with a number of important xenobiotics. The following are the principal points to have emerged from this study. 1. A minimum of twelve electrophoretically distinct patterns of induction of haemopolypeptides and other polypeptides could be distinguished after administration, either singly or in certain combinations, of phenobarbital, 3-methylcholanthrene, polychlorinated biphenyls, 2-acetylaminofluorene, safrole (or isosafrole), pregnenolone-16 alpha-carbonitrile and ethanol. The patterns consisted of various permutations of the amounts of eight polypeptides of 47000-56000 mol.wt., of which at least three were haemopolypeptides. The possible identities of these polypeptides, which included species of cytochrome P-450, cytochrome P-448 and epoxide hydratase, are discussed. 2. Agents (3-methylcholanthrene, benzo[a]-pyrene, polychlorinated biphenyls, 2,3,7,8-tetrachlorodibenzo-p-dioxin and beta-naphthoflavone) that result in the induction of cytochrome P-448 caused a marked increase in two polypeptides of 54000 and 56000 mol.wt., whereas safrole and isosafrole induced only the former polypeptide. 3. Administration of 2-acetylaminofluorene resulted in the induction of two polypeptides; evidence is presented that suggests that one of these is a species of epoxide hydratase [cf. Levin, Lu, Thomas, Ryan, Kizer & Griffin (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 3240-3243] ANd that the other may be a novel haemopolypeptide. 4. The overall results emphasize the complexity of the responses exhibited by rat liver microsomal fractions to the administration of xenobiotics.

2-Acetylaminofluorene↗
PubMed1978

Alcohol induced changes of carbohydrate metabolism [author's transl].

It is evident that ethanol by itself or one of its metabolites produces alterations in transport, metabolism and disposition of carbohydrates. Ethanol acts via changes in the redox state of co-factors; e.g. ethanol-induced hypoglycemia is due, partly, to the inhibition of hepatic gluconeogenesis by ethanol as a consequence of the increased NADH2/NAD ratio in patients whose glycogen stores are already depleted. On the other hand, hyperglycemia has also been described in patients with alcoholism. Although its mechanism is still obscure, abnormal hormonal secretion of insulin, catecholamines and glucocorticoids has been incriminated. Finally, structural changes of the liver and pancreas such as cirrhosis and pancreatitis produced by chronic alcohol consumption should also be considered as pathogenetic factors in a variety of clinical states involving deranged carbohydrate metabolism.

Alcoholism↗
PubMed1977

Treatment of resistant ascites by continuous ultrafiltration--reinfusion of ascitic fluid.

Eight patients with diuretic-resistant ascites due to cirrhosis were treated by reinfusion of concentrated ascitic fluid. In 11 procedures, with a mean duration of 21.9 hours, weight loss averaged 14.8 kg. Complications during reinfusion included septicemia in 1 procedure, left-sided heart failure in 5, pyrexia in 7 and coagulation abnormalities in 10. Ascites recurred within 2 months after reinfusion in all but one patient. Although this technique is an efficient and inexpensive method of treatment of ascites, it does not appear indicated in patients with cirrhosis and resistant ascites in view of the possibly serious complications associated with reinfusion and the poor long-term results.

Aged↗
PubMed1977

Effects of chronic ethanol administration in the rat: relative dependency on dietary lipids. II. Paradoxical role of linoleate in the induction of hepatic drug-metabolizing enzymes in vitro.

The effect of chronic ethanol administration on the hepatic microsomal cytochrome P-450 content and activities of NADPH - cytochrome P-450 reductase (EC 1.6.2.4), benzphetamine demethylase, aniline hydroxylase (EC 1.14.14.1), and of the microsomal ethanoloxidizing system were studied in various dietary models. When ethanol was given with linoleate as the only source of dietary lipid, the ethanol induction of these parameters was greater with diets containing 2 or 5% of total calories as linoleate than with diets containing 10% of total calories as linoleate. By contrast, when ethanol was given with high fat (35% of total calories) diets, the ethanol induction of these same parameters was slightly greater when linoleate provided 10% of total calories than when it provided 3% of calories. The apparent effect of dietary linoleate on the induction, by ethanol, of microsomal drug-metabolizing enzymes is markedly different when linoleate is given as the only source of dietary lipid as opposed to when it is given with other dietary lipids. Thus, conclusions on the effect of ethanol on hepatic microsomal drug-biotransformation enzymes, drawn from studies with dietary models in which linoleate provides the only source of dietary lipid, connot be extended to dietary modles of more complex lipid composition. When given as the only source of lipid, 2% of total calories in linoleate appears optimal for basal activity and inductibility, by ethanol, of mixed-function oxidases.

Alcoholism↗
PubMed1976

Chronic carriers of hepatitis B antigen (HBsAg). Histological, biochemical, and immunological findings in 31 voluntary blood donors.

Among 289 HBsAg carriers detected by the Montreal Red Cross Blood Transfusion Service and seen by our group, 31 submitted voluntarily to liver biopsy. These 31 carriers have now been followed for 10-33 months (mean: 23) and all remained positive for HBsAg. 15 of these 31 subjects had lived in institutions during infancy or childhood and none were drug users. Histological examinations revealed 24 cases of chronic persistent hepatitis (CPH), 2 cases of chronic aggressive hepatitis, 2 with steatosis, and 3 with normal liver. On repeated determination, 16 of the 31 subjects had at least one elevated transaminase level. Transaminases levels could not be correlated with the histological diagnosis. 4 cases had positive antinuclear antibodies, all in the CPH group, a finding that could not be correlated with any clinical, biological, or histological findings. The search for other autoantibodies and the immunoglobulin determinations were totally unrewarding. Thus, it appears that chronic HBsAg carriers in Montreal voluntary blood donors often have chronic hepatitis, usually persistent, occasionally aggressive; liver biopsy still remains the most useful approach in the evaluation of these HBsAg carriers. The HBsAg-carrier state seems to be well tolerated, but further long-term studies are needed to understand the natural history of this condition.

Adolescent↗
PubMed1976

Idiopathic portal hypertension.

Idiopathic portal hypertension is reported in five cases including one case of chronic arsenical intake and one case of chronic industrial vinyl chloride exposure. In all five cases the patients presented with gastrointestinal bleeding as the chief complaint. Physical examination was within normal limits except for splenomegaly in all. Results of liver function tests were normal, except for the relative clearance of sulfobromophtalein. A surgical liver biopsy specimen was obtained in all cases and showed moderate degrees of portal fibrosis, but no cirrhosis. Combined umbilicoportal, hepatic vein and superior mesenteric artery catheterization was performed in all cases. Hepatoportographies showed distortion of the intrahepatic portal venous system and cut-off of small portal venules. Porto-hepatic gradients ranged from 14.0 to 20.5 mm Hg. The portal hypertension was both sinusoidal and presinusoidal in nature but mainly presinusoidal. Hepatic extraction of indocyanine green and of albumin microaggregates was normal, thereby suggesting normal functional portal blood supply to the liver. The patients with arsenical or vinyl chloride exposure could not be differentiated from the other three patients with idiopathic portal hypertension. These results suggest that idiopathic portal hypertension may be related to domestic or industrial exposure to other hepatotoxins.

Adult↗
PubMedDate not supplied

Cytochrome P-450 measurement in rat liver homogenate and microsomes. Its use for correction of microsomal losses incurred by differential centrifugation.

Cytochrome P-450 was assayed in rat liver homogenates and microsomes in order to calculate microsomal recoveries and correct for losses during ultracentrifugation or sedimentation in presence of CaCl2. The values obtained for corrected microsomal protein in untreated female Sprague-Dawley rats were between 40 and 50 mg/g of liver. The assay of cytochrome P-450 in liver homogenate is accurate enough to calculate a reproducible recovery factor. The value of the method lies in its rapidity, its capacity to correct over a wide range of losses, and its capacity to yield reliable values of the total microsomal protein mass. The limits of this method include overestimation of homogenate cytochrome P-450 and inability to correct for nonmicrosomal protein contamination. Overestimation of cytochrome P-450 can be corrected by measuring the difference in absorbance between 450 and 510 nm with the extinction coefficient of 100 mM-1cm-1. To be accurate, cytochrome P-450 determination on microsomes must be done at protein concentrations of about 3 mg/ml. The error inherent to the method may be kept constant and minimal. The use of correction for microsomal losses is recommended in order to obtain uniformity between results from various laboratories and adequate correlation with in vivo studies of microsomal functions.

Acid Phosphatase↗