CATECHOLAMINE CONTENT OF THE RAT MEDIAN-EMINENCE FOLLOWING REMOVAL OF ENDOCRINE GLANDS

(1) The catecholamine (CA) content was determined in nerve terminals of the median eminence in normal, castrated and adrenalectomized male rats using quantitative microfluorimetry. (2) Noradrenaline (NA) concentrations in the subependymal layer (SEL) were unaffected by surgery. (3) Adrenalectomy decreased CA concentrations in the mixed population of NA and dopamine (DA) terminals in the medial palisade zone (MPZ). (4) Castration increased DA concentrations in MPZ and the lateral palisade zone (LPZ). (5) Adrenalectomy and castration had pronounced, but somewhat different, effects on the variations of CA fluorescence intensities in LPZ and MPZ, but no effect in the subependymal layer (SEL). (6) It is postulated that DA terminals in the external layers of the median eminence may interact with tanycytes in the feedback regulation of adrenal and gonadal hormones. © 1979.