Studies of neurophysin secreting neurons with immunoperoxidase techniques employing antibody to bovine neurophysin. I. Light microscopic findings in monkey and bovine tissues.

Hypothalamus and pituitary tissues from monkey and calf, fixed in Bouin's or formalin and embedded in paraffin, were deparaffinized and rehydrated and examined for the localization of neurophysin using immunoenzyme techniques. Rabbit antiserum to bovine neurophysin I was used as the specific antibody, with peroxidase labeled antirabbit globulin in the 2–layer method, and with unlabeled antirabbit and rabbit antiperoxidase sera followed by peroxidase in the 3–layer immunobridge technique. The brown reaction products of the localized peroxidase with 3,3' diaminobenzidine were seen by light microscopy. Tissues were counterstained by cresyl violet or aldehyde fuchsin. Neurophysin I levels in pooled cryostat sections of bovine supraoptic (SO) and paraventricular (PV) hypothalamic regions were determined by radioimmunoassay. With these methods, in both species neurophysin is localized in (1) SO and PV neuronal perikarya, (2) in their axons coursing through hypothalamus and (3) in their terminals in posterior pi...