ADRENALINUM An Internal Secretion of Suprarenal Glands (ADRENALIN) Adrenaline or Epinephrine, the active principle of the medulla of the suprarenal gland, (cortical secretion not as yet isolated), is employed as a chemical messenger in the regulation of the activities of the body; in fact, its presence is essential to the activity of the sympathetic nerve. Adrenaline action on any part is the same as stimulation of the sympathetic nerve endings thereto. Local application (1: 1,000 solution) to mucous membranes promptly induces transient ischemia, seen in a blanching , persisting several hours from conjunctival instillation. Its action is very prompt, efficient, evanescent , owing to rapid oxidation and therefore practically harmless, unless too frequently repeated, when atheroma and heart lesions--myocardial--in animals have been reported. Arteries, heart, supra-renal bodies and vaso-motor system are prominently affected. The main action o...