Preparation of antisera to three individual rat neurophysins and their use for radioimmunoassays.

A number of antisera have been raised against individual rat neurophysins. One of these proved suitable for the specific radioimmunoassay of rat vasopressin-neurophysin and data validating such a use are presented. Use of this antiserum showed that vasopressin-neurophysin is present in rat neurohypophyses in equimolar amounts to vasopressin, while in the hypothalamus the assay detected twice as much neurophysin-like material as hormone. A number of partially specific antisera for rat oxytocin-neurophysin have been obtained and the best of these was raised against the minor neurophysin.