Immunohistochemical evidence for the existence of angiotensin II-containing nerve terminals in the brain and spinal cord in the rat.

Using the indirect immunohistochemical method it has been possible to demonstrate angiotensin II or angiotensin II-like immunoreactivity in probable axons and nerve terminals in the brain and spinal cord of normal rat, resistant to bilateral nephrectomy. A high density of angiotensin II-cotaining nerve terminals has been found in the substantia gelatinosa of the spinal cord and the medulla oblongata, suggesting a role of this peptide in the mediation of sensory information to the CNS. A high density was found in the sympathetic lateral column, which supports the view that this peptide is involved in central blood pressure control. A plexus of angiotensin II nerve terminals in the locus coeruleus may control activity in the coerulocortical noradrenergic pathways. The existence of a substantial innervation of the medial external layer of the median eminence may suggest a role of angiotensin II in anterior pituitary control as, for example, a hypothalamic hormone.