Effects of guanyl nucleotides on CCKB receptor binding in brain tissue and continuous cell lines: a comparative study.
The effects of non-hydrolyzable guanyl nucleotide analogue GTP-gamma S on CCKB receptor binding in human and guinea-pig cortex, Jurkat T-cells, rat pituitary GH3 cells, rat glioma C6 cells and human small cell lung cancer NCI-H69 cells were investigated by using [3H]CCK-8S saturation and competition binding studies. GTP-gamma S caused inhibition of specific [3H]CCK-8S binding in a concentration dependent manner with a plateau at 10-25 microM. 25 microM GTP-gamma S resulted in a small but significant increase in Kd and IC50 values with amount very similar in all CCKB receptor models tested. However, the maximal number of specific [3H]CCK-8S binding sites (Bmax) was unaffected. Results suggest that CCKB receptors are G-protein coupled in a similar way to human and guinea-pig cortex, Jurkat cells, GH3 cells, C6 cells and NCI-H69 cells.
Kaufmann
R
R
Friedrich-Schiller-University Jena, Germany.
Schöneberg
T
T
Henklein
P
P
Meyer
R
R
Martin
H
H
Ott
T
T
D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D002460:Cell Line; D005625:Frontal Lobe / Q000187:drug effects* / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology*; D006168:Guinea Pigs; D006801:Humans; D011869:Radioligand Assay; D051381:Rats; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin / Q000378:metabolism*; D012844:Sincalide / Q000031:analogs & derivatives* / Q000378:metabolism; D014407:Tumor Cells, Cultured
C090019:8-sulfocholecystokinin octapeptide; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D012844:Sincalide