BLOOD-BORNE ADRENOCORTICOTROPIN BINDS SPECIFICALLY TO THE MEDIAN EMINENCE-ARCUATE REGION OF THE RAT HYPOTHALAMUS

The quantitative light microscope radioautographic approach was utilized to locate specific binding sites for blood-borne 125I-labeled ACTH1-24 in the rat brain. Specific binding occurred exclusively in the external zone of the median eminence, adjacent to the primary portal plexus, and to a lesser extent in the ventral arcuate nucleus. This localization may indicate that the hypophysiotropic medi…