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Burni FA, Agrawal NR, Walker M, Ali H, Raghavan SR. Complexity in a Simple Self-Assembling System: Lecithin-Water-Ethanol Mixtures Exhibit a Re-Entrant Phase Transition and a Vesicle-Micelle Transition (VMT) on Heating. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024. [PMID: 39158103 DOI: 10.1021/acs.langmuir.4c01235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/20/2024]
Abstract
We report surprising results for the self-assembly of lecithin (a common phospholipid) in water-ethanol mixtures. Lecithin forms vesicles (∼100 nm diameter) in water. These vesicles are transformed into small micelles (∼5 nm diameter) by a variety of destabilizing agents such as single-tailed surfactants and alcohols. In a surfactant-induced vesicle-micelle transition (VMT), vesicles steadily convert to micelles upon adding the surfactant─thereby, the turbidity of the solution drops monotonically. Instead, when an alcohol like ethanol is added to lecithin vesicles, we find a new, distinctive pattern in phase behavior as the ethanol fraction feth in water is increased. The turbidity first decreases (from feth = 0 to 37%), then rises sharply (feth = 37 to 50%), and then eventually decreases again (feth > 55%). Concomitant with the turbidity rise, the vesicles separate into two phases around feth = 50% before a single phase reappears at higher feth─in other words, there is a "re-entrant" phase transition from 1-phase to 2-phase and back to 1-phase with increasing feth. Vesicles near the phase boundary (∼feth = 45%) also show a VMT upon heating. Similar patterns are seen with other alcohols such as methanol and propanol. We ascribe these complex trends to the dual role played by alcohols: (a) first, alcohols reduce the propensity for flat lipid bilayers to bend and form closed spherical vesicles; and (b) second, alcohols diminish the tendency of lipids to self-assemble in the solvent mixture. At low alcohol fractions, (a) dominates, causing the initially unilamellar vesicles to grow into multilamellar vesicles (MLVs), which eventually phase-separate. Thereafter, (b) dominates, and the vesicles convert into micelles. Support for our hypothesis comes from scattering (SANS) and microscopy (cryo-TEM). Thus, we have uncovered a general paradigm for lipid self-assembly in solvent mixtures, and this may even have physiological relevance.
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Affiliation(s)
- Faraz A Burni
- Department of Chemical & Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Niti R Agrawal
- Department of Chemical & Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Maxwell Walker
- Department of Chemical & Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Hamna Ali
- Department of Chemical & Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Srinivasa R Raghavan
- Department of Chemical & Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, United States
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Loftis JM, Taylor J, Hudson R, Firsick EJ. Neuroinvasion and cognitive impairment in comorbid alcohol dependence and chronic viral infection: An initial investigation. J Neuroimmunol 2019; 335:577006. [PMID: 31325774 DOI: 10.1016/j.jneuroim.2019.577006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/03/2019] [Accepted: 07/09/2019] [Indexed: 12/16/2022]
Abstract
Viruses that invade the central nervous system (CNS) can cause neuropsychiatric impairments. Similarly, chronic alcohol exposure can induce inflammatory responses that alter brain function. However, the effects of a chronic viral infection and comorbid alcohol use on neuroinflammation and behavior are not well-defined. We investigated the role of heavy alcohol intake in regulating inflammatory responses and behavioral signs of cognitive impairments in mice infected with lymphocytic choriomeningitis virus (LCMV) clone 13. LCMV-infected mice exposed to alcohol had increased peripheral inflammation and impaired cognitive function (as indicated by performance on the novel object recognition test). Initial findings suggest that brain region-specific dysregulation of microglial response to viral infection may contribute to cognitive impairments in the context of heavy alcohol use.
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Affiliation(s)
- Jennifer M Loftis
- Research & Development Service, Veterans Affairs Portland Health Care System, Portland, OR, USA; Department of Psychiatry, Oregon Health & Science University, Portland, OR, USA; Methamphetamine Abuse Research Center, Veterans Affairs Portland Health Care System, Oregon Health & Science University, Portland, OR, USA.
| | - Jonathan Taylor
- Research & Development Service, Veterans Affairs Portland Health Care System, Portland, OR, USA; Department of Psychiatry, Oregon Health & Science University, Portland, OR, USA
| | - Rebekah Hudson
- Research & Development Service, Veterans Affairs Portland Health Care System, Portland, OR, USA; Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Evan J Firsick
- Research & Development Service, Veterans Affairs Portland Health Care System, Portland, OR, USA
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3
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Snitker S, Xie K, Ryan KA, Yu D, Shuldiner AR, Mitchell BD, Gong DW. Correlation of circulating MMP-9 with white blood cell count in humans: effect of smoking. PLoS One 2013; 8:e66277. [PMID: 23825535 PMCID: PMC3692499 DOI: 10.1371/journal.pone.0066277] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 05/03/2013] [Indexed: 12/03/2022] Open
Abstract
Background Matrix metalloproteinase-9 (MMP-9) is an emerging biomarker for several disease conditions, where white blood cell (WBC) count is also elevated. In this study, we examined the relationship between MMP-9 and WBC levels in apparently healthy smoking and non-smoking human subjects. Methods We conducted a cross-sectional study to assess the relationship of serum MMP-9 with WBC in 383 men and 356 women. Next, we divided the male population (women do not smoke in this population) into three groups: never (n = 243), current (n = 76) and former (n = 64) smokers and compared the group differences in MMP-9 and WBC levels and their correlations within each group. Results Circulating MMP-9 and WBC count are significantly correlated in men (R2 = 0.13, p<0.001) and women (R2 = 0.19, p<0.001). After stratification by smoking status, MMP-9 level was significantly higher in current smokers (mean ± SE; 663.3±43.4 ng/ml), compared to never (529.7±20.6) and former smokers (568±39.3). WBC count was changed in a similar pattern. Meanwhile, the relationship became stronger in current smokers with increased correlation coefficient of r = 0.45 or R2 = 0.21 (p<0.001) and steeper slope of ß = 1.16±0.30 (p<0.001) in current smokers, compared to r = 0.26 or R2 = 0.07 (p<0.001) and ß = 0.34±0.10 (p<0.001) in never smokers. Conclusions WBC count accounts for 13% and 19% of MMP-9 variance in men and women, respectively. In non-smoking men, WBC count accounts for 7% of MMP-9 variance, but in smoking subjects, it accounts for up to 21% of MMP-9 variance. Thus, we have discovered a previously unrecognized correlation between the circulating MMP-9 and WBC levels in humans.
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Affiliation(s)
- Soren Snitker
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Keming Xie
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Pathophysiology, Medical College of Soochow University, Suzhou, China
| | - Kathleen A. Ryan
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Daozhan Yu
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Alan R. Shuldiner
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Geriatrics Research and Education Clinical Center, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, United States of America
| | - Braxton D. Mitchell
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Da-Wei Gong
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Geriatrics Research and Education Clinical Center, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, United States of America
- * E-mail:
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Simon FR, Fortune J, Alexander A, Iwahashi M, Dahl R, Sutherland E. Increased hepatic Na,K-ATPase activity during hepatic regeneration is associated with induction of the beta1-subunit and expression on the bile canalicular domain. J Biol Chem 1996; 271:24967-75. [PMID: 8798777 DOI: 10.1074/jbc.271.40.24967] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Cellular and molecular mechanisms regulating the activity of the sodium pump or Na,K-ATPase during proliferation of hepatocytes following 70% liver resection have not been defined. Na,K-ATPase may be regulated by synthesis of its alpha- and beta-subunits, by sorting to either the sinusoidal or apical plasma membrane domains, or by increasing membrane lipid fluidity. This study investigated the time course of changes during hepatic regeneration for Na, K-ATPase activity, lipid composition and fluidity, and protein content of liver plasma membrane subfractions. As early as 4 h after hepatic resection, Na,K-ATPase activity was increased selectively in the bile canalicular fraction. It reached a new steady state at 12 h and remained elevated for 2 days. Although hepatic regeneration was associated with a reduced cholesterol/phospholipid molar ratio and increased fluidity, measured with two different probes, these changes in lipid metabolism were in the sinusoidal membrane domain. The Na,K-ATPase beta1-subunit, but not the alpha1-subunit, was increased selectively at the bile canalicular surface as shown by immunoblotting of liver plasma membrane subfractions and the morphological demonstration at both the light and electron microscopic levels. Furthermore, cycloheximide blocked the rise in beta1-subunit mRNA levels. Since the time course for beta1-subunit accumulation was similar to that for activation of Na,K-ATPase activity, this change implicated the beta1-subunit in activating sodium pump activity.
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Affiliation(s)
- F R Simon
- Department of Medicine, Hepatobiliary Research Center, University of Colorado Health Sciences Center and the Denver Veterans Affairs Medical Center, Denver, Colorado 80262, USA
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5
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Ganne-Carrié N, Kremsdorf D, Garreau F, Thévenin M, Petit MA, Nalpas B, Bréchot C. Effects of ethanol on hepatitis B virus Pre-S/S gene expression in the human hepatocellular carcinoma derived HEP G2 hepatitis B DNA positive cell line. J Hepatol 1995; 23:153-9. [PMID: 7499786 DOI: 10.1016/0168-8278(95)80329-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND/AIMS Among the reported interactions between ethanol and hepatitis B virus (HBV), studies of transgenic mice have suggested an effect of ethanol on the secretion of viral envelope proteins. METHODS We further investigated these interactions in vitro by determining HBs antigen levels and performing northern blots of viral mRNA in human cell culture (HepG2 HBV positive cells) exposed for 3 to 12 days to various concentrations of ethanol. RESULTS In cultures exposed to 200 mM ethanol, HBs antigen concentrations increased in the medium (p < 0.05) after 3 days as Pre-S1 and Pre-S2 protein concentrations. This increase was not specific, as albumin and ferritin increased in the same proportions. Ethanol also increased the HBs antigen concentration in the cells (p < 0.05), whereas levels of viral mRNA encoding surface proteins were unaffected. CONCLUSIONS These findings show that short-term ethanol exposure in vitro can induce HBs antigen overexpression via a post-transcriptional mechanism.
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Mizinga KM, Stino FK, Samaan SS, Soliman KF, Kolta MG. Hypothermic effect of ethanol in mice selected for differential sleep-time response to pentobarbital. Pharmacol Biochem Behav 1995; 51:525-8. [PMID: 7667380 DOI: 10.1016/0091-3057(95)00049-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The hypothermic action of ethanol was investigated in genetically distinct lines of mice selected for sleep-time response to pentobarbital for six generations. Ethanol (3 g/kg, intraperitoneally) was administered to alcohol-naive males and females from each of the unselected control, long-, and short-sleep mouse lines. Rectal temperatures were measured immediately before, and at 15, 30, 60, 90, 120, and 240 min after ethanol injection. Eight female and eight male mice from each line were sacrificed at each time point, and trunk blood was collected for plasma ethanol analysis. The results show that short-sleep mice were less hypothermic (p < 0.05) compared to long-sleep mice at 15 and 30 min after ethanol administration. However, plasma ethanol concentrations were not significantly different between the mouse lines at any time point. Therefore, the line-dependent differential ethanol-induced hypothermia observed may be a result of differences in "brain sensitivity" rather than in the rates of ethanol metabolism among the mouse lines.
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Affiliation(s)
- K M Mizinga
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee 32307, USA
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7
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Bjorkman DJ, Jessop LD. Effects of acute and chronic ethanol exposure on intestinal microvillus membrane lipid composition and fluidity. Alcohol Clin Exp Res 1994; 18:560-5. [PMID: 7943655 DOI: 10.1111/j.1530-0277.1994.tb00910.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Chronic ethanol consumption produces nutrient malabsorption. The mechanisms by which this occurs are poorly understood. One potential mechanism is an alteration in microvillus membrane (MVM) composition and fluidity. The effects of in vivo ethanol exposure on MVM lipid composition and fluidity were determined in rats fed either a standard diet or 15% ethanol in water for 2 months. Acute jejunal exposure to 4% ethanol was also performed in vivo in each feeding group. Acute exposure to ethanol produced an increase in static and dynamic membrane fluidity associated with a decrease in MVM cholesterol regardless of prior ethanol exposure. Chronic ethanol feeding alone did not alter membrane fluidity. Changes in membrane fatty acid composition were minor and variable after both acute and chronic ethanol exposure. Prior chronic ethanol feeding did not prevent the acute effects of ethanol on MVM composition or fluidity. These data support the theory that ethanol acutely disrupts nutrient transport by changing MVM lipid fluidity. The absence of adaptive changes in membrane composition and fluidity may also explain the persistent absorptive defects seen with chronic alcoholism.
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Affiliation(s)
- D J Bjorkman
- Division of Gastroenterology, Veterans Administration Medical Center, Salt Lake City, Utah
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8
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Odeleye OE, Eskelson CD, Mufti SI, Watson RR. Vitamin E attenuation of the effects of chronic ethanol and cod liver oil consumption on rat liver lipid composition. Nutr Res 1993. [DOI: 10.1016/s0271-5317(05)80811-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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9
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Wilson JS, Apte MV, Thomas MC, Haber PS, Pirola RC. Effects of ethanol, acetaldehyde and cholesteryl esters on pancreatic lysosomes. Gut 1992; 33:1099-1104. [PMID: 1398235 PMCID: PMC1379450 DOI: 10.1136/gut.33.8.1099] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Recent studies indicate that altered lysosomal function may be involved in the early stages of pancreatic injury. Chronic consumption of ethanol increases rat pancreatic lysosomal fragility. The aim of this study is to determine whether the lysosomal fragility observed after chronic ethanol consumption is mediated by ethanol per se, its oxidative metabolite acetaldehyde or cholesteryl esters (substances which accumulate in the pancreas after ethanol consumption). Pancreatic lysosomes from chow fed rats were incubated for 30 minutes at 37 degrees C with ethanol, acetaldehyde or phosphatidylcholine vesicles containing cholesteryl oleate. Lysosomal stability was then assessed by determination of: (a) Latency--that is, the per cent increase in lysosomal enzyme activity after addition of Triton X-100 and (b) Supernatant activity--that is, the proportion of lysosomal enzyme remaining in the supernatant after resedimentation of lysosomes. Acid phosphatase, N-acetyl glucosaminidase, beta-glucuronidase and cathepsin B were assayed as lysosomal marker enzymes. Lysosomes incubated with homogenising medium alone or equivalent volumes of phosphatidylcholine vesicles without cholesteryl oleate were used as controls. Cholesteryl oleate at concentrations of 15 and 20 mM increased pancreatic lysosomal fragility as shown by decreased latency and increased supernatant enzyme. In contrast, ethanol (150 mM) and acetaldehyde (5 mM) had no effect on lysosomal stability in vitro. These results suggest that increased pancreatic lysosomal fragility observed with ethanol may be mediated by cholesteryl ester accumulation rather than by ethanol or acetaldehyde.
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Affiliation(s)
- J S Wilson
- Department of Gastroenterology, Prince Henry Hospital, University of New South Wales, Sydney, Australia
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10
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Nalpas B, Pourcel C, Feldmann G, Housset C, Tiollais P, Bréchot C, Berthelot P, Farza H. Chronic alcohol intoxication decreases the serum level of hepatitis B surface antigen in transgenic mice. J Hepatol 1992; 15:118-24. [PMID: 1506627 DOI: 10.1016/0168-8278(92)90022-h] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hepatitis B virus (HBV) infections with an unusual serological profile, viz. positivity of HBV-DNA in the absence of hepatitis B surface antigen (HBsAg), have been described in alcoholics. This atypical pattern could be due to a low circulating level of viral particles rendering HBsAg undetectable with commercial kits, whereas HBV-DNA remains positive using the highly sensitive hybridization technique. We hypothesize that the well-known alcohol-induced impairment of protein secretion could also concern HBsAg particles and leads to a decrease in serum levels of the HBs antigen. To verify this hypothesis, we used HBsAg-positive transgenic mice as an animal model. Twelve HBsAg+ mice were separated into two groups; one group (n = 6) was submitted to increasing alcoholisation over an 18-week period, while the other (n = 6) was water fed. Seven HBsAg- littermates acted as controls: three received the alcohol regimen and the remaining four water. Chronic excessive alcoholisation lead to a significant decrease in serum HBsAg concentrations, while there was no obvious change in liver S mRNA. Ultrastructural studies showed a significant decrease in the number of microtubules in the livers of alcohol-fed mice. Finally, immunohistochemical studies performed at the end of the experiment showed a greater accumulation of HBsAg in the livers of HBsAg+ alcohol-fed (mainly located in the centrilobular area) than in the HBsAg+ water-fed mice. Our results (i) validate our initial hypothesis that chronic alcohol abuse leads to a decrease in serum HBsAg concentrations. This could explain, in part at least, the serological dissociations which were observed. (ii) Confirm the utility of screening serum HBV-DNA in alcoholics.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- B Nalpas
- Unité d'Hépatologie, Hôpital Laënnec, INSERM U-99, Paris, France
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11
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Pol S, Nalpas B, Vassault A, Bousquet-Lemercier B, Franco D, Lacour B, Berthelot P, Hanoune J, Barouki R. Hepatic activity and mRNA expression of aspartate aminotransferase isoenzymes in alcoholic and nonalcoholic liver disease. Hepatology 1991. [PMID: 1916663 DOI: 10.1002/hep.1840140408] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Affiliation(s)
- S Pol
- Unité d'Hépatologie, Hôpital Laënnec, Paris, France
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12
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Odeleye OE, Eskelson CD, Watson RR, Mufti SI, Chvapil M. Vitamin E reduction of lipid peroxidation products in rats fed cod liver oil and ethanol. Alcohol 1991; 8:273-7. [PMID: 1872988 DOI: 10.1016/0741-8329(91)90353-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The purpose of this study was to investigate the effects of vitamin E supplementation on ethanol- and cod liver oil-induced lipid peroxidation. Adult male rats received diets containing ethanol, cod liver oil and supplemented with vitamin E for 28 days. Following treatment, hepatic conjugated dienes, lipid fluorescence, and exhalation of ethane were measured as indices of lipid peroxidation. Ethane expiration over a 3-hour period was reduced by 96% in rats fed ethanol supplemented with vitamin E. Exhalation of ethane was increased by CLO feeding but was reduced 89% in the CLO-fed rats supplemented with vitamin E. In addition, ethane production was elevated in rats fed ethanol plus CLO compared to rats fed diets containing CLO supplemented with vitamin E. Supplementation of the CLO diet with vitamin E also significantly decreased hepatic conjugated fatty acid dienes levels. Levels of hepatic conjugated fatty acid dienes from rats fed ethanol plus vitamin E were reduced 91% compared to rats fed ethanol diets. Additionally, hepatic lipid fluorescence expressed as per mg of hepatic phospholipid basis was also significantly increased in rat groups fed vitamin E, ethanol, and cod liver oil diets. Where vitamin E was added to these same diets a significant decrease of hepatic lipid peroxidation products occurred. The observed reduction in lipid peroxidation by vitamin E may be useful to retard lipid peroxides derived materials involved in the development of alcoholic liver diseases.
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Affiliation(s)
- O E Odeleye
- Department of Family and Community Medicine, University of Arizona, Tucson 85724
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13
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Sévilla E, Valette A, Gastaldi M, Boyer J, Vérine A. Effect of ethanol intake on lipoprotein lipase activity in rat heart. Biochem Pharmacol 1991; 41:2005-9. [PMID: 2039549 DOI: 10.1016/0006-2952(91)90142-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We examined the effects of the in vivo administration of ethanol on lipolytic activities assayed in rat post-heparin heart effluents, that hydrolyse tri-, di- and monoacylglycerol. Properties of triacylglycerol lipase (TAGL) are typical of lipoprotein lipase (LPL) whereas diacylglycerol (DAGL) and monoacylglycerol (MAGL) lipase activities hydrolyse sequentially the products of LPL action. After 15 days of ethanol intake, TAGL, DAGL and MAGL activities in post-heparin heart effluents were decreased respectively by 25, 38 and 22%; after 30 days, the decreases amounted to 81, 79 and 71%. After 30 days, but not after 15 days, ethanol increased the levels of triacylglycerol in plasma. Ethanol intake concomitantly decreased TAGL and DAGL activities in post-heparin effluents and in heart tissue extracts, whereas MAGL activity was decreased only in the latter extracts. We conclude that ethanol intake causes a marked impairment in heart LPL and in two closely-related heparin-releasable activities, seemingly by altering the production of a catalytically active enzyme. A distinct heparin-unreleasable MAGL appears to exist in heart, that could be ethanol-insensitive. Overall, the results suggest that a LPL-related alteration in fatty acid supply could contribute to the toxicity of ethanol in heart.
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Affiliation(s)
- E Sévilla
- INSERM U 260, Faculté de Médicine, Marseille, France
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14
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Gonzales RA, Crews FT. Chronic ethanol inhibits receptor-stimulated phosphoinositide hydrolysis in rat liver slices. Alcohol 1991; 8:131-6. [PMID: 1648364 DOI: 10.1016/0741-8329(91)91321-r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effects of chronic ethanol feeding on norepinephrine (NE)- and arginine-vasopressin (AVP)-stimulated phosphoinositide (PI) hydrolysis in rat liver slices was determined. The maximum NE-stimulated PI response was significantly reduced by 40% in liver slices from 8-month-old rats which had been treated for 5 months with a liquid diet containing ethanol compared to pair-fed controls. The maximum AVP-stimulated PI response was decreased by 39% in liver slices from the ethanol-fed rats compared to control. EC50 values for NE- and AVP-stimulated PI hydrolysis in liver slices were not affected by the chronic ethanol treatment. Similar reductions in the maximal NE- and AVP-stimulated PI hydrolysis (28% and 27%, respectively) were found in 22-month-old rats which had been maintained on an ethanol containing diet for 5 months compared to pair-fed controls. The binding of [3H]prazosin and [3H]AVP to liver plasma membranes from 8-month-old ethanol-fed rats was not significantly different from binding to liver membranes from sucrose-fed controls. Our data suggest that chronic ethanol ingestion may lead to a reduction in PI-linked signal transduction in liver.
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Affiliation(s)
- R A Gonzales
- Department of Pharmacology, University of Texas, Austin 78712
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16
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Abstract
Total parenteral nutrition with an amino acid-glucose solution has previously been shown to decrease rat hepatic drug metabolism compared with drug metabolic activity observed in rats receiving the same solution enterally and chow-fed animals. Because changes in membrane fluidity and lipid composition are reported to influence activity of a number of liver enzymes, effects of parenteral and enteral nutrition on hepatic microsomal membrane fluidity and lipid composition were assessed and compared with hepatic mixed-function oxidase activity. Both parenteral and enteral hyperalimentation produced a significant decrease in microsomal membrane fluidity (fluorescence anisotropy = 0.155 +/- 0.003 in both experimental groups versus 0.129 +/- 0.003 for microsomes from chow-fed animals). However, meperidine demethylase activity was significantly decreased compared with chow-fed experiments only in hepatic microsomes from parenterally hyperalimented animals, whereas ethoxyresorufin deethylase activity was significantly reduced only in the enteral-nutrition group. Inclusion of lipid in the parenterally administered hyperalimentation solution normalized microsomal membrane fluidity and lipid profile to those of chow-fed animals but did not increase hepatic meperidine demethylation. Both parenteral and enteral nutrition produce significant changes in physical state and lipid composition of rat hepatic microsomal membranes, but these changes are not responsible for the altered hepatic drug metabolism observed during hyperalimentation.
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Affiliation(s)
- R G Knodell
- Division of Gastroenterology, University of Maryland/Baltimore VA Medical Center
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Krähenbühl S, Meier-Abt PJ, Reichen J. Taurocholate transport by liver plasma membrane vesicles is not altered in cirrhotic rats. J Hepatol 1989; 9:1-9. [PMID: 2549120 DOI: 10.1016/0168-8278(89)90068-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Recently, we have shown that taurocholate transport is impaired in hepatocytes isolated from CCl4 cirrhotic rats. Na+,K+-ATPase activity depends on the lipid composition of the surrounding membrane. Therefore, we performed this study in order to detect differences in plasma membrane composition and membrane functions between livers of CCl4 cirrhotic (n = 17) and of control rats (n = 15). After biochemical characterization of the animals we isolated basolateral and canalicular membrane vesicles and determined membrane enzyme activities, transport functions and lipid composition. We found no differences in the isolation characteristics of the plasma membranes between the two groups. The lipid composition of the membrane fractions was not altered, except for a lower cholesterol content in the canalicular membranes of the cirrhotic group (200 +/- 15 vs. 246 +/- 18 micrograms/mg protein, P less than 0.05). Taurocholate transport into basolateral membrane vesicles and marker enzyme activities of the membrane fractions were also equal in control and cirrhotic animals. We conclude that the plasma membrane composition and membrane enzyme/transport activities have returned to normal in CCl4 cirrhotic rats 14 days after cessation of exposure to CCl4. Thus, a disturbed transport system is not the cause for the observed decreased taurocholate transport into hepatocytes from cirrhotic rats. Even a cirrhotic liver has a high potential for recovery after acute CCl4 intoxication.
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Affiliation(s)
- S Krähenbühl
- Department of Clinical Pharmacology, University of Berne, Switzerland
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Abstract
Liver injury may develop in some people who consume alcohol. The pathogenesis of liver damage in such subjects remains obscure. Major histopathologic features of alcohol-associated liver injury include steatosis, steatonecrosis, and cirrhosis. The clinical manifestations of alcoholic liver disease are nonspecific and range from asymptomatic hepatomegaly to stigmata of portal hypertension with advanced parenchymal failure. The severity of the clinical presentation and the degree of aminotransferase elevation correlate poorly with the liver histopathology, particularly in patients who continue to drink alcohol. Short-term mortality of such patients is best predicted by a composite of clinical and laboratory parameters that are influenced by alcohol consumption as well as by liver disease. Long-term prognosis is determined by residual damage to vital organs (that is, whether or not cirrhosis has developed) and whether or not the patient continues to drink. Current therapy of alcoholic liver disease includes abstinence and correction of nutritional deficiencies. Other therapies are experimental and are best utilized in the setting of controlled clinical trials.
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Affiliation(s)
- A M Diehl
- Gastroenterology-Hepatology Division, Georgetown University, Washington DC
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19
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Wilson JS, Korsten MA, Pirola RC. Alcohol-induced pancreatic injury (Part 2). Evolution of pathogenetic theories. INTERNATIONAL JOURNAL OF PANCREATOLOGY : OFFICIAL JOURNAL OF THE INTERNATIONAL ASSOCIATION OF PANCREATOLOGY 1989; 4:233-50. [PMID: 2668435 DOI: 10.1007/bf02938460] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In Part I of this paper, features of alcoholic pancreatitis that are still poorly understood were reviewed and factors that might favor biliary-pancreatic reflux were summarized. Part II deals with additional pathogenetic schemes that might shed light on this perplexing disorder.
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Affiliation(s)
- J S Wilson
- Department of Gastroenterology, Prince Henry Hospital, Sydney, Australia
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20
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Pascale R, Daino L, Garcea R, Frassetto S, Ruggiu ME, Vannini MG, Cozzolino P, Feo F. Inhibition by ethanol of rat liver plasma membrane (Na+,K+)ATPase: protective effect of S-adenosyl-L-methionine, L-methionine, and N-acetylcysteine. Toxicol Appl Pharmacol 1989; 97:216-29. [PMID: 2538005 DOI: 10.1016/0041-008x(89)90327-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
(Na+,K+)ATPase activity of rat liver plasma membranes was evaluated in female rats feeding an ethanol containing diet for 46 days (total ethanol ingested, 59.7 g/100 g body wt). Determinations were performed at the end of ethanol treatment or at various times after stopping treatment. (Na+,K+)ATPase and 5'-nucleotidase activities exhibited a 8- and 1.4-fold decrease, respectively, at the end of ethanol ingestion. In contrast no modifications of Mg2+-ATPase activity were observed. There also occurred, in ethanol-treated rats, release of sorbitol dehydrogenase into the blood, fat accumulation in liver cells, and decrease in reduced glutathione (GSH) liver content. A decrease in (Na+,K+)ATPase activity was also found in plasma membranes isolated from hepatocyte suspensions after a 2-hr incubation with 50 mM ethanol or 1 mM acetaldehyde (ACA), in conditions that caused a great fall in hepatocyte GSH content but did not cause cell death. After the cessation of ethanol administration, there occurred a progressive recovery of (Na+,K+)ATPase activity, GSH and triacylglycerol content, and release of sorbitol dehydrogenase. These parameters reached control values 12 hr after ethanol withdrawal. S-Adenosyl-L-methionine (SAM), L-methionine, and N-acetylcysteine (NAC), given to rats during ethanol treatment, prevented the decrease in (Na+,K+)ATPase activity and GSH content. They also reduced steatosis and liver necrosis. The efficiency of these compounds decreased in this order: SAM, methionine, NAC. SAM accelerated the recovery of all parameters studied after ethanol withdrawal, and also protected (Na+,K+)ATPase activity and GSH content of isolated hepatocytes from the deleterious effect of ethanol. These SAM effects were prevented by 1-chloro-2,4-dinitro-benzene, a compound which depletes cell GSH. Treatment of isolated hepatocytes with [35S]SAM led to the synthesis of labeled GSH. The total amount and specific activity of labeled GSH underwent a significant increase, in the presence of 2 mM ethanol or 0.5 mM ACA, which indicates a marked stimulation of GSH synthesis by ethanol and ACA. These data indicate that ethanol intoxication may inhibit (Na+,K+)ATPase activity; an effect that does not seem to depend on cell necrosis. SAM, methionine, and NAC exert various degrees of protection toward ethanol-induced cell injury, which are related to the efficiency of these compounds in maintaining a high GSH pool.
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Affiliation(s)
- R Pascale
- Istituto di Patologia generale dell'Università di Sassari, Italy
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21
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Wilson JS, Korsten MA, Leo MA, Lieber CS. Combined effects of protein deficiency and chronic ethanol consumption on rat pancreas. Dig Dis Sci 1988; 33:1250-9. [PMID: 3168698 DOI: 10.1007/bf01536675] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
This study was performed in order to delineate the combined effects of protein deficiency and chronic ethanol ingestion on the rat pancreas. Rats fed ethanol in combination with protein-deficient diets developed marked steatosis, whereas alcohol ingestion with nutritionally adequate diets and protein deficiency alone each were associated with a more moderate degree of pancreatic lipid accumulation. On biochemical analysis, it was found that protein deficiency decreased pancreatic phospholipid content. Furthermore, both protein deficiency and chronic ethanol consumption increased pancreatic cholesteryl ester content, and their effects were additive. Functional changes were studied using isolated pancreative acini. Protein deficiency depressed the tissue content of lipase and the ability of pancreatic acini to secrete lipase. Chronic ethanol feeding increased lipase levels in the acini and also their secretory capacity. Thus, to the extent that enzyme accumulation in the pancreas plays a role in the pathogenesis of alcoholic pancreatitis, these results may explain the higher incidence of pancreatitis in well-nourished alcoholics that has been documented in dietary surveys.
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Affiliation(s)
- J S Wilson
- Alcohol Research Center, V.A. Medical Center, Bronx, NY 10468
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22
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Abstract
To study possible mechanisms whereby vitamin A and ethanol may affect liver plasma membranes, rats were fed liquid diets containing either 6 international units of vitamin A per kcal or 5 times more, with or without ethanol (36% of total energy as isocaloric substitution for carbohydrate). Vitamin A supplementation resulted in 2- to 3-fold increases of liver plasma membrane free retinol (p less than 0.005) and retinyl esters (p less than 0.001), particularly esters of palmitate and oleate, whereas cholesterol esters did not change. The fluorescent probe 1,6-diphenyl-1,3,5-hexatriene revealed decreased fluidity as measured by an increase in fluorescence polarization which correlated significantly with retinyl palmitate plus oleate content in membranes. In rats fed ethanol chronically, we first verified our previous observation of a decrease in liver plasma membrane fluorescence polarization. We now find this effect to be associated with (and possibly due to) an increase of cholesterol ester content. In linear regression analysis, the change in fluorescence polarization correlated positively with vitamin A (p less than 0.02) and negatively with cholesterol ester contents (p less than 0.001). Ethanol feeding partially offset the effect of vitamin A supplementation on fluorescence polarization. We conclude from these observations that liver plasma membranes contain a significant amount of vitamin A, that vitamin A supplementation increases membrane fluorescence polarization and that chronic ethanol administration can interfere with this effect.
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Affiliation(s)
- C I Kim
- Alcohol Research and Treatment Center, Bronx Veterans Administration Medical Center, New York 10468
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Teschke R, Krukenberg S, Stremmel W, Nishimura M. Enhanced biliary gamma-glutamyltransferase excretion following prolonged alcohol consumption in rats. Eur J Clin Invest 1987; 17:347-53. [PMID: 2889602 DOI: 10.1111/j.1365-2362.1987.tb02199.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In order to study the question of whether chronic ethanol consumption may alter the biliary excretion of gamma-glutamyltransferase (gamma-GT), female rats were pair-fed nutritionally adequate liquid diets containing either ethanol (36% of total calories) or isocaloric carbohydrates for 24 days. Compared to pair-fed controls, the administration of the alcohol-containing diet resulted in an increased biliary excretion of gamma-GT (5.84 +/- 0.73 mU 6 h-1 100 g-1 b.w. vs. 8.82 +/- 0.79, P less than 0.001). This was associated with a corresponding enhanced biliary output of total bile acids. An apparent linear relation between the biliary output rates of gamma-GT and those of total bile acids was observed both in alcohol-fed animals (r = 0.83) and in their pair-fed controls (r = 0.95). In addition, there was a significant increase of gamma-glutamyltransferase activities in the liver homogenate and in liver plasma membranes, both in fractions rich in bile canalicular and basolateral membranes and in those rich in blood sinusoidal site. Serum gamma-glutamyltransferase activities as well as serum bile acid concentrations were also enhanced by 96.8% (P less than 0.001) and 233% (P less than 0.001), respectively. These data show that chronic alcohol consumption enhances hepatic gamma-GT activities, leading to an increased efflux of gamma-GT into the bile and possibly into the blood out of the liver cell. Furthermore, these data suggest the involvement of bile acids with their solubilizing properties for the biliary excretion of gamma-GT.
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Affiliation(s)
- R Teschke
- Medical Department D, University of Düsseldorf, FRG
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24
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Sieg A, Seitz HK. Increased production, hepatic conjugation, and biliary secretion of bilirubin in the rat after chronic ethanol consumption. Gastroenterology 1987; 93:261-6. [PMID: 3596161 DOI: 10.1016/0016-5085(87)91012-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Disturbances of bilirubin metabolism such as jaundice or pigment gallstone formation, or both, occur in alcoholic cirrhosis of the liver. We have studied the influence of chronic ethanol consumption on bilirubin metabolism as well as on biliary calcium and bile acids in 16 pair-fed male rats. The animals received nutritionally adequate liquid diets containing 36% of total calories either as ethanol or isocaloric carbohydrates for 4 wk. Bile flow was significantly enhanced after chronic ethanol feeding (p less than 0.05 after 90-min bile collection) and was found to be mainly bile acid-independent. The biliary output and concentration of bilirubin monoconjugates, bilirubin diconjugates, and total calcium was significantly increased (p less than 0.01) in alcohol-fed rats compared with controls. This was not the case for unconjugated bilirubin and for the calcium/bile acid ratio. Hepatic bilirubin uridine-5'-diphosphate-glucuronosyltransferase activity (p less than 0.01), serum total bilirubin (p less than 0.01), and serum free hemoglobin (p less than 0.001) were significantly increased after ethanol consumption. These data provide evidence for enhanced bilirubin production, probably due to hemolysis, after alcohol ingestion. The enhanced bile production is associated with an increased hepatic conjugation and subsequent biliary secretion of bilirubin conjugates. In advanced alcoholic liver disease, these compensatory mechanisms may fail and contribute to the development of jaundice.
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Delpéro C, Gastaldi M, Vérine A, Campistron M, Boyer J. Increased monoester lipase activity of red blood cells in alcoholism. Alcohol Clin Exp Res 1986; 10:602-5. [PMID: 3544911 DOI: 10.1111/j.1530-0277.1986.tb05152.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Monoester lipase activity was assayed by a radiochemical assay in the red blood cells (RBC) from 50 chronic alcoholic patients within 48 hr after discontinuation of chronic alcohol intake and from 40 nonalcoholic control subjects. The mean value of lipase activity was increased to 1213 +/- 229 milliunits/10(12) RBC in the alcoholics as compared with a value of 997 +/- 120 milliunits/10(12) RBC in the controls (p less than 0.001). The lipase increase was associated with increased values of the mean cellular volume of RBC. A subgroup (64%) of 32 alcoholic subjects with macrocytosis (mean cellular volume greater than 96 femtoliters) showed the highest mean lipase activity (1276 +/- 224 milliunits/10(12) RBC) as compared with a value of 1101 +/- 196 milliunits/10(12) RBC in the normocytic alcoholic subgroup (p less than 0.05). This latter subgroup had a mean value higher (p less than 0.05) than that in the control group. The relationship between values of mean cellular volume and lipase activity was not of predictive value in individual cases. The enzymatic increase was not related to a direct effect of alcohol on the intact RBC. It is postulated that this alteration might result from changes in the chemical and/or physical state of the plasma membrane induced by ethanol during RBC formation. In any event, the increased lipolytic activity of RBC represents a new biological characteristic of alcoholic subjects. Its determination might represent a noninvasive way of evaluating the influence of alcohol on a tissue parameter.
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