Uptake of 131I-metaiodobenzylguanidine by 6-23 rat medullary thyroid carcinoma.
Uptake of 131iodine-metaiodobenzylguanidine (131I-MIBG) by 6-23 rat medullary thyroid carcinoma (MTC), was studied in vitro and in vivo. In vitro, there was an 8-fold increase in 131I uptake by 6-23 cells when labeled with 131I-MIBG (131I 24 +/- 15 cpm/10(6) cells, 131I-MIBG 196 +/- 9 cpm/10(6) cells). MIBG uptake in vitro was the same at 4 degrees C and 37 degrees C. In contrast, 131I-MIBG uptake by PC-12 rat pheochromocytoma cells were 200 times greater (131I-MIBG 42,412 +/- 6,755 cpm/10(6) cells). 131I-MIBG uptake by rat MTC cells in vitro were of a comparable magnitude to the uptake of 131I-MIBG by rat ileal enterochromaffin cells (RIE-1) and mouse colon cancer cells (MC-26). In vivo, uptake of 131I-MIBG by 6-23 MTC tumor was considerably less than in the normal tissues (muscle, liver, spleen, kidney, adrenal and thyroid). Gamma camera studies of 131I-MIBG uptake by 6-23 MTC tumors growing in Wag-Rij rats were only transiently positive in 1 out of 4 rats studied. We conclude that 131I-MIBG is poorly taken up by rat medullary thyroid carcinoma and is an unpredictable marker for localization of rat MTC.
Poston
G J
GJ
Department of Surgery, University of Texas Medical Branch, Galveston.
Fawcett
H D
HD
Townsend
C M
CM
James
E
E
Lieg
J L
JL
Nusynowitz
M L
ML
Thompson
J C
JC
D019797:3-Iodobenzylguanidine; D000310:Adrenal Gland Neoplasms / Q000378:metabolism; D000818:Animals; D015740:Calcitonin Gene-Related Peptide; D002277:Carcinoma / Q000378:metabolism*; D003110:Colonic Neoplasms / Q000378:metabolism; D004759:Enterochromaffin Cells / Q000378:metabolism; D007082:Ileum / Q000378:metabolism; D007457:Iodine Radioisotopes; D007462:Iodobenzenes / Q000378:metabolism* / Q000493:pharmacokinetics; D051379:Mice; D009368:Neoplasm Transplantation; D009479:Neuropeptides / Q000097:blood; D010673:Pheochromocytoma / Q000378:metabolism; D051381:Rats; D013964:Thyroid Neoplasms / Q000378:metabolism*; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured
D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D009479:Neuropeptides; D019797:3-Iodobenzylguanidine; D015740:Calcitonin Gene-Related Peptide