The synthesis and release of vasopressin and oxytocin.
Vasopressin (AVP) and oxytocin are synthesised in the magnocellular neurones of the supraoptic and paraventricular nuclei. Each neurone synthesises either oxytocin or vasopressin. These peptides anise from the precursor molecules pro-oxyphysin and propressophysin, respectively. The neurophysin-nonapeptide groups migrate, in the form of neurosecretory granules, along the axons of the magnocellular neurones, to be stored at the ends of the neuronal tracts. When the neurones ΓÇÿfireΓÇÖ, the granules fuse with the axonal plasmalemma and each nonapeptide and its specific neurophysin are subsequently released separately. Once released, the neurophysin has no apparent physiological function.
