Neurotensin high affinity binding sites and endopeptidase 24. 11 are present respectively in the meningothelial and in the fibroblastic components of human meningiomas

Journal Article · Thu Nov 01 04:00:00 EST 1990 · Peptides (Fayetteville, New York); (USA)

DOI:https://doi.org/10.1016/0196-9781(90)90159-3· OSTI ID:5583508

Mailleux, P; Przedborski, S; Beaumont, A; Verslijpe, M; Depierreux, M; Levivier, M; Kitabgi, P; Roques, B P; Vanderhaeghen, J J ^[1]

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1. Brugmann Hospital, Bruxelles (Belgium)

The presence of neurotensin receptors and endopeptidase 24.11 (E-24.11) in 16 human meningioma specimens, obtained at surgery, was assessed by measuring the binding of {sup 125}I-(tyrosyl3)neurotensin(1-13) ({sup 125}I-NT) and the inhibitor {sup 3}H-N(2RS)-3-hydroxyaminocarbonyl-2-benzyl-1-(oxopropyl)glycine ({sup 3}H-HACBO-Gly), for the receptor and enzyme, respectively. E-24.11 activity was also measured. Autoradiography, on the 16 meningiomas, showed that specific {sup 125}I-NT labeling (nonspecific labeling was assessed in the presence of excess NT) was exclusively located in the meningothelial regions. In contrast, specific {sup 3}H-HACBO-Gly labeling (nonspecific labeling was assessed in the presence of an excess of the E-24.11 inhibitor thiorphan) was exclusively found in fibroblastic regions. No specific labeling of either ligand was found on collagen or blood vessels. In vitro binding assays were performed on membranes of 10 of the 16 meningiomas. In the 4 meningiomas rich in meningothelial cells, {sup 125}I-NT specifically bound to one population of sites with Bmax ranging from 57 to 405 fmol/mg protein and Kd around 0.3 nM. These sites share common properties with the brain NT receptor, since the carboxy terminal acetyl NT(8-13) fragment bound to the same sites but with a higher affinity. The carboxy terminal analogue of NT, neuromedin N, also bound to the same sites with a 10-fold lower affinity and the sites were bradykinin and levocabastine insensitive. In the 4 meningiomas rich in fibroblastic cells, {sup 3}H-HACBO-Gly specifically bound to one population of sites with Bmax ranging from 251 to 739 fmol/mg protein and Kd around 2.8 nM.

• OSTI ID: 5583508
• Journal Information: Peptides (Fayetteville, New York); (USA), Journal Name: Peptides (Fayetteville, New York); (USA) Vol. 11:6; ISSN 0196-9781; ISSN PPTDD
• Country of Publication: United States
• Language: English

Related Subjects

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59 BASIC BIOLOGICAL SCIENCES
AFFINITY
ANIMAL CELLS
ANIMALS
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CELL CONSTITUENTS
CELL MEMBRANES
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
ENZYME ACTIVITY
ENZYME INHIBITORS
ENZYMES
FIBROBLASTS
HYDROLASES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
KINETICS
LIGANDS
MAMMALS
MAN
MEMBRANE PROTEINS
MEMBRANES
MENINGES
NEOPLASMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HYDROLASES
PEPTIDES
PRIMATES
PROTEINS
RADIOISOTOPES
REACTION KINETICS
RECEPTORS
SOMATIC CELLS
VERTEBRATES