Distribution and Concentration of Adrenaline and Noradrenaline in the Adrenal Medulla of the Rat Following Reserpine‐Induced by Muscular Work

E ränkö O. and M. H ärkönen . Distribution and concentration of adrenaline and noradrenaline in the adrenal medulla of the rat following depletion induced by muscular work. The rats were allowed to run for 16 hours, to rest for 12 hours and to run again for 10 hours. They were killed immediately, 3, 6, 12 or 19 days thereafter. Concentrations of adrenaline and noradrenaline in the adrenal medulla were measured chemically. The intensities of the chromaffin reaction, the iodate reaction and formalin‐induced fluorescence in adrenal sections were quantitated by microphotometry. Running caused an almost complete loss of both catecholamines from the adrenal medulla and the histochemical reactions turned almost negative. The catecholamine concentrations and the histochemical reactions returned to normal in 6 days. During the recovery phase the behaviour of the noradrenaline‐storing medullary cells differed histochemically from that of the adrenaline‐storing cells.