Ultrastructural localization of nerve terminals containing nitric oxide synthase in rat adrenal gland.

摘要

Immunoelectron microscopy was performed to localize immunoreactivity for nitric oxide synthase (NOS) in rat adrenal gland. NOS-immunoreactive (NOS-ir) nerve fibers were observed around blood vessels and endocrine cells in the zona glomerulosa of the cortex. Electron microscopy showed that NOS-ir axon varicosities were in close contact with the smooth muscles of blood vessels and with the cytolemma of endocrine cells. In the adrenal medulla, several NOS-ir ganglion cells were found. Synaptic contacts between non-immunoreactive axons and dendrites of NOS-ir neurons were observed. NOS-ir nerve fibers were distributed among chromaffin cells. Positive axon varicosities were in close contact with the catecholamine-storing chromaffin cells. These results suggest that NOS-ir nerve cells control directly the secretion of corticosteroid and catecholamine in addition to the vascular tone.