Cytological Demonstration of Noradrenaline in the Suprarenal Medulla Under Conditions of Varied Secretory Activity

Oxidation of noradrenaline in vitro with potassium iodate gives a selective pigment formation, making possible differentiation from adrenaline (Hillarp and Hokfelt, 1953). When applied cytologically to the adrenal medulla this reaction of pigment formation suggested that noradrenaline is stored within special medullary cells. These investigations, however, did not exclude the possibility that the “noradrenaline cells” are non-specific, representing only varying degrees of secretory activity in the medulla. Using the above method for cytological demonstration of noradrenaline the adrenal medulla has now been studied under different conditions of secretory activity. MATERIALS AND METHODS Only adult cats and rats were used.—In order to obtain minimal secretory activity from the suprarenal medulla denervation was performed. In four cats all nerves innervating the medulla were cut close to the adrenal gland. In the rat (21 animals) by an intraabdominal approach the great splanchnic nerve was cut immediately cranial to its exit from the thorax;