Histochemical Demonstration of Uptake of Exogenous Norepinephrine by Adrenergic Fibers in vitro

Abstract

Adrenergic fibers in isolated iris preparations were demonstrated histochemically by means of the formaldehyde condensation technique. In the presence of adenosine triphosphate (ATP) there was a net uptake of norepinephrine added in vitro by the adrenergic fibers producing a striking increase in fluorescence. In the absence of ATP only a slight increase in fluorescence was observed when the tissue was exposed to high concentrations of norepinephrine.