131I

Examination of the results of the unsymmetrical sulfonamides 131i-k (entries 11-13) reveals an interesting trend. The methyl/i-propyl sulfonamide 131i repre-... 

Antithyroid drugp or thyroid antagonists are used to treat hyperthyroidism. In addition to the antithyroid drugs, hyperthyroidism may be treated by the administration of strong iodine solutions, use of radioactive iodine (131I), or by surgical removal of some or almost all of the tiiyroid gland (subtotal thyroidectomy). 

Reactions after administration of 131I include sore diroat, swelling in the neck, nausea, vomiting, cough, and pain on swallowing. Otiier reactions include bone marrow depression, anemia, leukopenia, thrombocytopenia, and tachycardia... 

Once a euthyroid state is achieved, tlie primary health care provider may add a thyroid hormone to tlie therapeutic regimen to prevent or treat hypothyroidism, which may develop slowly during long-term antithyroid drug therapy or after administration of 131I. 

Synthetic hCT Is not commercially available now. Most assays have been developed by using hormone supplied as gifts from the CIBA-Gelgy Co., Basel, Switzerland for 131i or labeling. Immunization and standards although several useful antisera have been produced by Immunization with crude extracts of medullary carcinoma tissue. 

Figure 8 Comparison of ability of WIN 55, 212-2 to sedate mice (triangles) and to block specific binding of [131I]AM281 (squares).

Figure 9 Graph of inhibition of acetylcholine release in superfused hippocampal slices versus CB1 receptor occupancy estimated from inhibition of [131I]AM281 binding.

Figure 10 Effect of increasing doses of AM281 on binding of [131I]AM281 in cerebellum and hippocampus, using brain stem as reference tissue.

These factors make 125I the iodine label of choice for radiolabeling biological molecules. Its commercial availability from a number of suppliers at relatively low cost further adds to its popularity. Even though it has lower specific activity than 131I, iodine-125 still provides much greater sensitivity than 14C, 32P, 35S, or 3H in labeling biomolecules. In fact, the use of a radioactive iodine label can create probes that have 150-fold more sensitivity than tritiated molecules and as much as 35,000 times the detectability of 14C-labeled molecules (Bolton and Hunter, 1986). 

The partial meltdown of the 1000-megawatt reactor at Chernobyl on April 26, 1986, released large amounts of radionuclides into the environment — especially 131I, 137Cs, and 134Cs — and... 

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