CHEMICAL ISOLATION AND DETERMINATION OF CATECHOLAMINES IN MEDIAN EMINENCE AND PARS NERVOSA OF RAT AND HORSE

Catecholamines isolated from extracts of the median eminence region, the rest of the hypothalamus, and the pars nervosa of the rat and horse by the alumina adsorption method were determined by three fluorimetric methods. In both species, the hypothalamus contained the highest concentration of noradrenaline, while the median eminence contained both noradrenaline and dopamine in about the same concentration. We found the highest concentration of dopamine, in addition to a slight amount of noradrenaline, in the pars nervosa. This result was further confirmed in the horse pars nervosa with Dowex SOW resin column chromatography. Dopamine may be involved in the regulation of the release of neurosecretory substances in the median eminence and pars nervosa. © 1969 S. Karger AG, Basel.