Autoradiographic distribution of bombesin/gastrin-releasing peptide receptors in fetal cortex transplants.
Bombesin/gastrin-releasing peptide (BB/GRP) receptors were characterized in fetal cortex transplants in the rat. Using in vitro autoradiography techniques, the density of (125I-Tyr4)BB grains was low 2 weeks after transplantation but increased 4 weeks after cortex transplantation into the adult rat fourth ventricle. Densitometry analysis of the autoradiograms indicated that (125I-Tyr4)BB bound with high affinity (Kd = 5 nM) to a single class of sites in the transplant tissue. Specific (125I-Tyr4)BB binding was inhibited with high affinity by (Tyr4)BB but not by NMB (IC50 values of 3 and 100 nM, respectively). These data suggest that GRP may act as a novel growth factor and play a regulatory role in the development of fetal cortex transplants.
Department of Biochemistry and Molecular Biology, George Washington University Medical Center, Washington, DC 20037, USA.
T W
TW
Moody
R
R
Getz
J M
JM
Rosenstein
D000367:Age Factors; D000818:Animals; D001345:Autoradiography; D002540:Cerebral Cortex / Q000737:chemistry / Q000637:transplantation*; D016332:Fetal Tissue Transplantation; D007457:Iodine Radioisotopes; D010456:Peptides, Cyclic; D051381:Rats; D018004:Receptors, Bombesin / Q000032:analysis*; D012249:Rhombencephalon / Q000737:chemistry / Q000601:surgery
D007457:Iodine Radioisotopes; D010456:Peptides, Cyclic; D018004:Receptors, Bombesin; C096284:cyclolinopeptide A, Tyr(4)-