Vasopressin, oxytocin and neurophysins in the human brain and spinal cord.

The concentrations of arginine vasopressin, oxytocin, and their related neurophysins were compared in many areas of postmortem human brain and spinal cord using specific radioimmunoassays. In the hypothalamus the ratio of vasopressin to oxytocin was approximately 3:1, and in the extrahypothalamic areas of the brain the greatest amount of both peptides was present in the locus coeruleus, and to a lesser extent the periaqueductal grey. Vasopressin only was found in the substantia nigra, and globus pallidus. In the medulla, including the nucleus of the solitary tract, the dorsal nucleus of the vagus, and the nucleus of the spinal tract of the trigeminal nerve, the amount of oxytocin was greater than that of vasopressin. In the spinal cord oxytocin predominated over vasopressin to an even greater extent, and reached particularly high values in certain segments of the intermediolateral grey column and dorsal horn. Estrogen-stimulated and nicotine-stimulated neurophysins (ESN and NSN) were both found in large amounts in those areas of the brain and spinal cord where the concentrations of the nonapeptides were greatest, but when the molar ratios of ESN to oxytocin and NSN to vasopressin were compared there was an excess of ESN.