TYPE-B CHOLECYSTOKININ RECEPTORS ON RAT GLIOMA C-6 CELLS - BINDING-STUDIES AND MEASUREMENT OF INTRACELLULAR CALCIUM MOBILIZATION

Citation
R. Kaufmann et al., TYPE-B CHOLECYSTOKININ RECEPTORS ON RAT GLIOMA C-6 CELLS - BINDING-STUDIES AND MEASUREMENT OF INTRACELLULAR CALCIUM MOBILIZATION, Brain research, 639(1), 1994, pp. 109-114
Citations number
33
Categorie Soggetti
Neurosciences
Journal title
ISSN journal
00068993
Volume
639
Issue
1
Year of publication
1994
Pages
109 - 114
Database
ISI
SICI code
0006-8993(1994)639:1<109:TCRORG>2.0.ZU;2-O
Abstract
To our knowledge, no brain derived cell line has been shown as yet to bear cholecystokinin(CCK)(B) receptors. In this paper, CCK binding sit es were identified on rat C-6 glioma cells. Pharmacological characteri zation demonstrated a single class of high affinity binding sites (K-d = 1.7 +/- 0.3 x 10(-10) M) and a binding capacity of 6.1 +/- 1.8 fmol / mg protein. These CCK binding sites displayed a typical CCKB pharmac ological profil as shown in competition studies by using several CCK-r elated compounds and nonpeptide CCK antagonists discriminating between CCKA and CCKB sites. In order to demonstrate that CCK binding sites c onstitute a functional receptor CCK-8S induced mobilization of free in tracellular calcium was investigated in single C-6 cells by using a la ser scanning confocal imaging system. Since rise in [Ca2+](i) noted by stimulation of C-6 cells with CCK-8S could be blocked by the CCKB rec eptor antagonist L-365,260 (100 nM) but not by the CCKA receptor antag onist L-364,718 (100 nM), CCK induced calcium signal is triggered by a ctivation of CCKB receptors in C-6 cells. The rat C-6 glioma cell line may serve as a useful model for studying CCKB receptor in brain.