title: Met-enkephalin receptors in human gliomas.
abstract: Endogenous opioid systems (opioid peptides and receptors) are involved in many functions including the regulation of cell growth. We investigated the presence of Met-enkephalin binding sites in gliomas by displacement assays. Results demonstrated that few gliomas exhibit Met-enkephalin binding sites and that the percentage of tumours which express these binding sites strongly decreases with increasing malignancy. Moreover, we observed a shift from mu Met-enkephalin binding sites in low grade gliomas to delta Met-enkephalin binding sites in high grade gliomas. These results suggest an inactivation of the Met-enkephalinergic system in gliomas which could lead to loss of the inhibitory effect exerted by Met-enkephalin on normal astrocyte growth and thus favour progression of malignancy.
authors.affiliation: Unité INSERM 318, Hôpital Michallon, Grenoble, France.
authors.forename: L
authors.initials: L
authors.lastname: Molin
authors.forename: J M
authors.initials: JM
authors.lastname: Verna
authors.forename: M F
authors.initials: MF
authors.lastname: Nissou
authors.forename: A L
authors.initials: AL
authors.lastname: Benabid
mesh_terms: D001665:Binding Sites; D005910:Glioma / Q000378:metabolism*; D006801:Humans; D011957:Receptors, Opioid / Q000145:classification / Q000378:metabolism*; D017465:Receptors, Opioid, delta / Q000378:metabolism; D017450:Receptors, Opioid, mu / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; C033593:methionine-enkephalin receptor