Immunohistochemical Studies on the Distribution of Endogenous Digitalis-like Substance (EDLS)-Containing Neurons in the Rat Hypothalamus, with Special Consideration on the Possibility of Their Coexistence with Posterior Lobe Hormones

Abstract

The distribution of the perikarya of endogenous digitalis-like substance (EDLS)-containing neurons in the rat hypothalamus was studied by immuno-histochemistry using digoxin and digitoxin antiserum. In addition, the possible coexistence of EDLS and posterior lobe hormones was examined using an immunohistochemical double-staining technique. Digoxin-like immunoreactive neurons were demonstrated in the paraventricular and supraoptic nuclei and other hypothalamic areas. However, digitoxin-like immunoreactive neurons were not detected in the hypothalamus. A portion of the digoxin-like immunoreactive neurons showed immunoreactivity for vasopressin or oxytocin. From these results, it is suggested that these digoxin-like immunoreactive neurons correspond to “EDLS-produc-ing neurons,” and that EDLS seems to act not only as a natriuretic substance but also as a neurohormone or neurotransmitter. © 1988, International Society of Histology and Cytology. All rights reserved.