title: Rapid clearance of iodine-131 MIBG from the heart and liver of patients with adrenergic dysfunction and pheochromocytoma.
abstract: Iodine-131 MIBG, a radiolabeled adrenergic neuron-blocking agent, decreased rapidly from the heart and liver of patients with adrenergic dysfunction (n = 3) and pheochromocytoma (n = 2) when compared with eight controls. The 4-hr activity expressed as percentages (mean +/- s.d.) of the 20-min counts were as follows: 80 +/- 3.0% in the controls compared with 60 +/- 7.6% in the patients over the heart (p less than 0.01) and 79 +/- 3.2% in the controls compared with 51 +/- 17% in the patients over the liver (p less than 0.02). However, there was no significant difference in the rate of [131I]MIBG decrease in these organs between controls and patients in the intervals subsequent to 4 hr (p greater than 0.05). These findings suggest that adrenergic neuronal uptake of [131I]MIBG in these organs is smaller in the patients than in the controls. Measurements of time-activity relationships of radioiodinated MIBG may be useful for assessment of adrenergic function of these organs and thus of generalized disorders of adrenergic innervation.
mesh_terms: D019797:3-Iodobenzylguanidine; D000310:Adrenal Gland Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism*; D000328:Adult; D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000000981:diagnostic imaging / Q000378:metabolism*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D007457:Iodine Radioisotopes / Q000378:metabolism*; D007462:Iodobenzenes / Q000378:metabolism*; D008099:Liver / Q000000981:diagnostic imaging / Q000378:metabolism*; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D010673:Pheochromocytoma / Q000000981:diagnostic imaging / Q000378:metabolism*; D011877:Radionuclide Imaging; D012791:Shy-Drager Syndrome / Q000000981:diagnostic imaging / Q000378:metabolism*; D013997:Time Factors
chemical_list: D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D019797:3-Iodobenzylguanidine