The occurrence of aminopeptidase N and desquamated cell proteins in intestinal perfusate of the rat

Vibeke Andersen, G H Hansen, Hans Gunnar Sjöström, O Norén

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

The in vivo release of a microvillar enzyme, aminopeptidase N (EC 3.4.11.2), and a cytosolic enzyme, lactate dehydrogenase (EC 1.1.1.27), into the intestinal lumen was measured to gain information on the fraction of desquamated cell protein in intestinal juice and on the mechanism of release of intestinal microvillar enzymes. 1.6% and 2.9% of the mucosal activities of aminopeptidase N and lactate dehydrogenase were released to the intestinal lumen per hour, respectively. The ratios between aminopeptidase N and lactate dehydrogenase in intestinal perfusates and mucosal homogenates were similar. This result is compatible with the view that aminopeptidase N in the rat small intestine is predominantly released into the intestinal lumen by desquamation of enterocytes. This conclusion was supported by the failure to demonstrate microvesiculation of the microvilli by electron microscopy. 30-40% of the aminopeptidase N in the intestinal lumen is membrane-bound indicating that partial solubilization occurs during desquamation. The addition of calcium ions did not augment the release of aminopeptidase N or the membrane-bound fraction in the lumen. 10-20% of the protein content in the intestinal lumen is due to extruded cell protein. This includes aminopeptidase N which constitutes 1% of the luminal protein.
OriginalsprogEngelsk
TidsskriftBBA General Subjects
Vol/bind967
Udgave nummer1
Sider (fra-til)43-8
Antal sider6
ISSN0304-4165
StatusUdgivet - 13. okt. 1988

Fingeraftryk

CD13 Antigens
L-Lactate Dehydrogenase
Proteins
Enzymes
Gastrointestinal Contents
Membranes
Enterocytes
Microvilli
Small Intestine
Electron Microscopy
Ions

Citer dette

Andersen, Vibeke ; Hansen, G H ; Sjöström, Hans Gunnar ; Norén, O. / The occurrence of aminopeptidase N and desquamated cell proteins in intestinal perfusate of the rat. I: BBA General Subjects. 1988 ; Bind 967, Nr. 1. s. 43-8.
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abstract = "The in vivo release of a microvillar enzyme, aminopeptidase N (EC 3.4.11.2), and a cytosolic enzyme, lactate dehydrogenase (EC 1.1.1.27), into the intestinal lumen was measured to gain information on the fraction of desquamated cell protein in intestinal juice and on the mechanism of release of intestinal microvillar enzymes. 1.6{\%} and 2.9{\%} of the mucosal activities of aminopeptidase N and lactate dehydrogenase were released to the intestinal lumen per hour, respectively. The ratios between aminopeptidase N and lactate dehydrogenase in intestinal perfusates and mucosal homogenates were similar. This result is compatible with the view that aminopeptidase N in the rat small intestine is predominantly released into the intestinal lumen by desquamation of enterocytes. This conclusion was supported by the failure to demonstrate microvesiculation of the microvilli by electron microscopy. 30-40{\%} of the aminopeptidase N in the intestinal lumen is membrane-bound indicating that partial solubilization occurs during desquamation. The addition of calcium ions did not augment the release of aminopeptidase N or the membrane-bound fraction in the lumen. 10-20{\%} of the protein content in the intestinal lumen is due to extruded cell protein. This includes aminopeptidase N which constitutes 1{\%} of the luminal protein.",
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The occurrence of aminopeptidase N and desquamated cell proteins in intestinal perfusate of the rat. / Andersen, Vibeke; Hansen, G H; Sjöström, Hans Gunnar; Norén, O.

I: BBA General Subjects, Bind 967, Nr. 1, 13.10.1988, s. 43-8.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - The occurrence of aminopeptidase N and desquamated cell proteins in intestinal perfusate of the rat

AU - Andersen, Vibeke

AU - Hansen, G H

AU - Sjöström, Hans Gunnar

AU - Norén, O

PY - 1988/10/13

Y1 - 1988/10/13

N2 - The in vivo release of a microvillar enzyme, aminopeptidase N (EC 3.4.11.2), and a cytosolic enzyme, lactate dehydrogenase (EC 1.1.1.27), into the intestinal lumen was measured to gain information on the fraction of desquamated cell protein in intestinal juice and on the mechanism of release of intestinal microvillar enzymes. 1.6% and 2.9% of the mucosal activities of aminopeptidase N and lactate dehydrogenase were released to the intestinal lumen per hour, respectively. The ratios between aminopeptidase N and lactate dehydrogenase in intestinal perfusates and mucosal homogenates were similar. This result is compatible with the view that aminopeptidase N in the rat small intestine is predominantly released into the intestinal lumen by desquamation of enterocytes. This conclusion was supported by the failure to demonstrate microvesiculation of the microvilli by electron microscopy. 30-40% of the aminopeptidase N in the intestinal lumen is membrane-bound indicating that partial solubilization occurs during desquamation. The addition of calcium ions did not augment the release of aminopeptidase N or the membrane-bound fraction in the lumen. 10-20% of the protein content in the intestinal lumen is due to extruded cell protein. This includes aminopeptidase N which constitutes 1% of the luminal protein.

AB - The in vivo release of a microvillar enzyme, aminopeptidase N (EC 3.4.11.2), and a cytosolic enzyme, lactate dehydrogenase (EC 1.1.1.27), into the intestinal lumen was measured to gain information on the fraction of desquamated cell protein in intestinal juice and on the mechanism of release of intestinal microvillar enzymes. 1.6% and 2.9% of the mucosal activities of aminopeptidase N and lactate dehydrogenase were released to the intestinal lumen per hour, respectively. The ratios between aminopeptidase N and lactate dehydrogenase in intestinal perfusates and mucosal homogenates were similar. This result is compatible with the view that aminopeptidase N in the rat small intestine is predominantly released into the intestinal lumen by desquamation of enterocytes. This conclusion was supported by the failure to demonstrate microvesiculation of the microvilli by electron microscopy. 30-40% of the aminopeptidase N in the intestinal lumen is membrane-bound indicating that partial solubilization occurs during desquamation. The addition of calcium ions did not augment the release of aminopeptidase N or the membrane-bound fraction in the lumen. 10-20% of the protein content in the intestinal lumen is due to extruded cell protein. This includes aminopeptidase N which constitutes 1% of the luminal protein.

KW - Aminopeptidases

KW - Animals

KW - Antigens, CD13

KW - Cytosol

KW - Intestines

KW - L-Lactate Dehydrogenase

KW - Male

KW - Microscopy, Electron

KW - Microvilli

KW - Rats

KW - Rats, Inbred Strains

M3 - Journal article

C2 - 2901858

VL - 967

SP - 43

EP - 48

JO - B B A - General Subjects

JF - B B A - General Subjects

SN - 0304-4165

IS - 1

ER -