Studies on catecholamine-containing granules of specific cells in cyclostome hearts.

Abstract : Preliminary experiments showed that incubation of isolated granules from the hearts of Petromyzon and Myxine with reserpine caused an increased rate of release of the catecholamines. In the present paper the specific cells and their storage granules were further studied with histological and electron microscopical techniques. The distribution and occurrence of catecholamines and other catechol substances in extracts of cyclostome hearts was studied with chromatographic technique. The effects of reserpine on the storage granules in vivo and in vitro are also described. In addition, some findings concerning the action of catecholamines on the activity of the isolated heart from Myxine after pretreatment with reserpine are reported.