| [ Summary ] |
Although calcitonin is a peptide hormone that inhibits osteoclastic bone resorption, it may also play a role as a neuropeptide because calcitonin receptors are distributed in the central nervous system. Analgesic action is one of neuropeptide actions of calcitonin. Repeated systemic administration of calcitonin gradually increases analgesic effect, which lasts for a long time after discontinuation of dosage. The serotonergic system, especially dorsal raphe serotonergic neurons, may be at least involved in analgesic action of calcitonin. Calcitonin receptor mRNA is expressed in the somata of serotonergic neurons, but it is unclear whether systemic injection of calcitonin acts directly on calcitonin receptors on the serotonergic neuron to induce analgesia. |