The presence of mu-, delta-, and kappa-opioid receptors in human heart tissue

摘要: Functional evidence suggests that the stimulation of peripheral and central opioid receptors (ORs) is able to modulate heart function. Moreover, selective either cardiac or ORs evokes preconditioning and, therefore, protects against ischemic injury. However, anatomic for OR subtypes in human scarce. Human tissue obtained during autopsy after sudden death was examined immunohistochemically mu- (MOR), kappa- (KOR), delta- (DOR) subtypes. MOR DOR immunoreactivity found mainly myocardial cells, as well on sparse individual nerve fibers. KOR identified predominantly cells intrinsic adrenergic (ICA) cell-like structures. Double immunofluorescence confocal microscopy revealed colocalized with neuronal marker PGP9.5, sensory neuron calcitonin gene-related peptide (CGRP). CGRP-immunoreactive (IR) fibers were detected bundles containing varicose-like Our findings offer first hint an basis existence by demonstrating their presence CGRP-IR fibers, small eccentric nucleus resembling ICA cells. Taken together, this role opioids both neural transmission regulation cell