Molecular pharmacology of the calcitonin receptor.

The peptide hormone calcitonin is widely used therapeutically in the treatment of bone disorders such as Paget's disease, osteoporosis, and the hypercalcemia of some malignancies. However, emerging evidence suggests the actions of calcitonin via its G protein-coupled receptor, the calcitonin receptor, may not be limited to bone. Calcitonin receptors have also been identified in the central nervous system, testes, skeletal muscle, lymphocytes, and the placenta. We are now becoming aware that the complexity of the calcitonin response mediated by the calcitonin receptor can be influenced by accessory proteins, receptor isoforms, genetic polymorphisms, developmental and/or transcriptional regulation, feedback inhibition, and the specific cellular or tissue background. This article discusses what is known about the molecular and pharmacological actions of the calcitonin receptor and highlights areas of current research.