Atrial natriuretic peptide in the median eminence is of paraventricular nucleus origin.

Atrial natriuretic peptide (ANF)-containing cells in the paraventricular nucleus are the major, if not the only source of ANF-containing nerve fibers and terminals in the median eminence. One week after bilateral lesioning of the paraventricular nucleus, immunoreactive ANF disappeared almost completely (87-92%) from the median eminence. The paraventriculo-median eminence ANF system appears to be distinct from the periventricular ANF system. Since adrenalectomy did not influence median eminence ANF levels in either sham-operated or paraventricular nucleus-lesioned animals, but depleted ANF levels in the preoptic and hypothalamic periventricular nuclei, it would appear that the latter system is intimately involved in the CNS control of fluid and electrolyte homeostasis.