Localization and regulation of vasopressin mRNA in human neurons

Vasopressin (prepropressophysin) mRNA is detected in neurons of the supraoptic, suprachiasmatic, and paraventricular nuclei of human postmortem hypothalamic specimens by quantitated in situ hybridization using ³⁵S‐labeled single‐stranded cDNA probes directed against exon C of the human vasopressin gene. This hybridization displays the anticipated anatomic distribution, as well as several biochemical features supporting its specificity. Hybridization densities in supraoptic neurons, a measure of vasopressin gene expression, display substantial variability from‐brain‐to‐brain. We can attribute much of this brain‐to‐brain variability to differences in antemortem extracellular volume status. This conclusion is based on (a) animal models of the human postmortem process, (b) animal models of common agonal events, (c) good correlations between antemortem volume status and neuronal vasopressin mRNA hybridization densities in human postmortem specimens matched for age and postmortem interval, and (d) our inability to correlate human neuronal vasopressin mRNA hybridization densities with other clinical and postmortem features. These results provide an example of antemortem regulation of a human neuroendocrine gene using postmortem tissue.