Cation exchange—a common mechanism in the storage and release of biogenic amines stored in granules (vesicles)?

Studies on the uptake and storage of sodium and biogenic amines (phenylethylamine, noradrenaline, histamine) by two weak cation-exchangers, IRC-50 and Sephadex C-50, and by biogenic granule-enriched preparations demonstrated that the synthetic and biogenic materials had several common characteristics. They showed similar concentration- and pH-dependence and fitted the same cation-exchange and receptor-binding equations. The observations were taken to support the view that the matrices of amine-storing granules have the properties of weak cation-exchangers, with carboxyls as the cation-binding groups.