Like the M 1 and M 3 muscarinic receptor, M 5 receptors are coupled with G proteins of class Gq that upregulate phospholipase C and, therefore, inositol trisphosphate and intracellular calcium as a signaling pathway.
Radioactive iodine is a very effective type of treatment for cancer of the thyroid gland. Thyroid cells absorb iodine. The radioactive iodine from the drink or capsule is absorbed into your body and picked up by the thyroid cancer cells wherever they are. So it can kill the cancer cells even if they have spread.
Taking iodine at these levels eliminates breast pain from fibrocystic changes about 70 percent of the time.2 In one recent study of women with breast pain, more than half of those who took 6 mg of iodine daily reported a significant reduction in overall breast pain.3.