Livingston A, Morris B
Cell Tissue Res. 1986;244(2):467-9. doi: 10.1007/BF00219223.
Electron-microscopic autoradiography of rat neurohypophyses treated with [3H] clonidine, an alpha 2-agonist, showed that binding apparently occurred preferentially at the neurosecretory endings and blood vessels rather than on the pituicytes. Since it is known that clonidine has a high affinity for plasma proteins, the distribution over the neurosecretory nerve endings would suggest the existence of presynaptic alpha 2-binding sites on neurosecretory neurones, which could indicate a regulatory function for catecholamines in neurohypophysial hormone release.