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.
For example, they have been shown to kill: 1  Non-specific human cancer cells (12) 2  Breast cancer cells (13) 3  Colorectal cancer cells (14) 4  Prostate cancer (15) 5  Malignant brain tumors (16) 6  Liver cancer (17) 7  Skin cancer (18) 8  UVB-induced skin cancer (19)