Abstract

We examined the effect of ethanol administration on intravesicular pH in intact hepatocytes by applying a flow cytometric technique to detect fluorescein-isothiocyanate-dextran (FITC-dextran) in acidic vesicles. Rats were pair-fed liquid diets containing either ethanol or isocaloric carbohydrate for 1 to 5 weeks. Our study showed that ethanol administration increased the in situ pH of hepatic lysosomes by 0.15 to 0.2 pH units. This pH increase was sufficient to cause a significant reduction in lysosomal protein degradation. Long-term ethanol administration also caused a significant alkalinization of hepatic endosomes, and this increased pH was sustained over the course of vesicular acidification in hepatocytes incubated in vitro. Direct exposure of hepatocytes from rats fed control diet to either 25 mmol/L ethanol or 50 μmol/L colchicine also brought about a rapid alkalinization of acidic vesicles in a manner that resembled that seen in hepatocytes from ethanol-fed rats. These same treatments augmented the vesicular alkalinization already present in cells from ethanol-fed animals. Although ethanol administration had no effect on the content of the hepatic mannose-6-phosphate/IGFII receptor, the results indicate that sustained alkalinization of endosomes could have important functional consequences by impairing M-6-P/IGFII receptor recycling, thereby disrupting the delivery of newly synthesized hydrolases to lysosomes. This decreased complement of hydrolases within lysosomes together with alkalinization of the intralysosomal compartment would result in an overall decrease in lysosomal proteolysis.

Original languageEnglish (US)
Pages (from-to)929-934
Number of pages6
JournalHepatology
Volume26
Issue number4
DOIs
StatePublished - Oct 1997

Fingerprint

Hepatocytes
Ethanol
Lysosomes
Endosomes
Hydrolases
Proteolysis
Liver
Diet
IGF Type 2 Receptor
Colchicine
Carbohydrates

ASJC Scopus subject areas

  • Hepatology

Cite this

Flow cytometric analysis of vesicular pH in rat hepatocytes after ethanol administration. / Kharbanda, Kusum; McVicker, Daniel L.; Zetterman, Rowen K; MacDonald, Richard G; Donohue, Terrence.

In: Hepatology, Vol. 26, No. 4, 10.1997, p. 929-934.

Research output: Contribution to journalArticle

@article{3554745536d94abe982c58d488cec0dc,
title = "Flow cytometric analysis of vesicular pH in rat hepatocytes after ethanol administration",
abstract = "We examined the effect of ethanol administration on intravesicular pH in intact hepatocytes by applying a flow cytometric technique to detect fluorescein-isothiocyanate-dextran (FITC-dextran) in acidic vesicles. Rats were pair-fed liquid diets containing either ethanol or isocaloric carbohydrate for 1 to 5 weeks. Our study showed that ethanol administration increased the in situ pH of hepatic lysosomes by 0.15 to 0.2 pH units. This pH increase was sufficient to cause a significant reduction in lysosomal protein degradation. Long-term ethanol administration also caused a significant alkalinization of hepatic endosomes, and this increased pH was sustained over the course of vesicular acidification in hepatocytes incubated in vitro. Direct exposure of hepatocytes from rats fed control diet to either 25 mmol/L ethanol or 50 μmol/L colchicine also brought about a rapid alkalinization of acidic vesicles in a manner that resembled that seen in hepatocytes from ethanol-fed rats. These same treatments augmented the vesicular alkalinization already present in cells from ethanol-fed animals. Although ethanol administration had no effect on the content of the hepatic mannose-6-phosphate/IGFII receptor, the results indicate that sustained alkalinization of endosomes could have important functional consequences by impairing M-6-P/IGFII receptor recycling, thereby disrupting the delivery of newly synthesized hydrolases to lysosomes. This decreased complement of hydrolases within lysosomes together with alkalinization of the intralysosomal compartment would result in an overall decrease in lysosomal proteolysis.",
author = "Kusum Kharbanda and McVicker, {Daniel L.} and Zetterman, {Rowen K} and MacDonald, {Richard G} and Terrence Donohue",
year = "1997",
month = "10",
doi = "10.1002/hep.510260419",
language = "English (US)",
volume = "26",
pages = "929--934",
journal = "Hepatology",
issn = "0270-9139",
publisher = "John Wiley and Sons Ltd",
number = "4",

}

TY - JOUR

T1 - Flow cytometric analysis of vesicular pH in rat hepatocytes after ethanol administration

AU - Kharbanda, Kusum

AU - McVicker, Daniel L.

AU - Zetterman, Rowen K

AU - MacDonald, Richard G

AU - Donohue, Terrence

PY - 1997/10

Y1 - 1997/10

N2 - We examined the effect of ethanol administration on intravesicular pH in intact hepatocytes by applying a flow cytometric technique to detect fluorescein-isothiocyanate-dextran (FITC-dextran) in acidic vesicles. Rats were pair-fed liquid diets containing either ethanol or isocaloric carbohydrate for 1 to 5 weeks. Our study showed that ethanol administration increased the in situ pH of hepatic lysosomes by 0.15 to 0.2 pH units. This pH increase was sufficient to cause a significant reduction in lysosomal protein degradation. Long-term ethanol administration also caused a significant alkalinization of hepatic endosomes, and this increased pH was sustained over the course of vesicular acidification in hepatocytes incubated in vitro. Direct exposure of hepatocytes from rats fed control diet to either 25 mmol/L ethanol or 50 μmol/L colchicine also brought about a rapid alkalinization of acidic vesicles in a manner that resembled that seen in hepatocytes from ethanol-fed rats. These same treatments augmented the vesicular alkalinization already present in cells from ethanol-fed animals. Although ethanol administration had no effect on the content of the hepatic mannose-6-phosphate/IGFII receptor, the results indicate that sustained alkalinization of endosomes could have important functional consequences by impairing M-6-P/IGFII receptor recycling, thereby disrupting the delivery of newly synthesized hydrolases to lysosomes. This decreased complement of hydrolases within lysosomes together with alkalinization of the intralysosomal compartment would result in an overall decrease in lysosomal proteolysis.

AB - We examined the effect of ethanol administration on intravesicular pH in intact hepatocytes by applying a flow cytometric technique to detect fluorescein-isothiocyanate-dextran (FITC-dextran) in acidic vesicles. Rats were pair-fed liquid diets containing either ethanol or isocaloric carbohydrate for 1 to 5 weeks. Our study showed that ethanol administration increased the in situ pH of hepatic lysosomes by 0.15 to 0.2 pH units. This pH increase was sufficient to cause a significant reduction in lysosomal protein degradation. Long-term ethanol administration also caused a significant alkalinization of hepatic endosomes, and this increased pH was sustained over the course of vesicular acidification in hepatocytes incubated in vitro. Direct exposure of hepatocytes from rats fed control diet to either 25 mmol/L ethanol or 50 μmol/L colchicine also brought about a rapid alkalinization of acidic vesicles in a manner that resembled that seen in hepatocytes from ethanol-fed rats. These same treatments augmented the vesicular alkalinization already present in cells from ethanol-fed animals. Although ethanol administration had no effect on the content of the hepatic mannose-6-phosphate/IGFII receptor, the results indicate that sustained alkalinization of endosomes could have important functional consequences by impairing M-6-P/IGFII receptor recycling, thereby disrupting the delivery of newly synthesized hydrolases to lysosomes. This decreased complement of hydrolases within lysosomes together with alkalinization of the intralysosomal compartment would result in an overall decrease in lysosomal proteolysis.

UR - http://www.scopus.com/inward/record.url?scp=0030848421&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030848421&partnerID=8YFLogxK

U2 - 10.1002/hep.510260419

DO - 10.1002/hep.510260419

M3 - Article

C2 - 9328315

AN - SCOPUS:0030848421

VL - 26

SP - 929

EP - 934

JO - Hepatology

JF - Hepatology

SN - 0270-9139

IS - 4

ER -