RADIOAUTOGRAPHIC LOCALIZATION OF NOREPINEPHRINE-H³ IN THE TISSUES OF MICE

¹ Pharmacology Laboratory, Ohio State University College of Medicine, Columbus, and Neurochemistry Laboratory, Cleveland Psychiatric Institute and Hospital, Cleveland, Ohio

The radioautographic localization of norepinephrine-H³ in some tissues of mice has been described. In the first few minutes after injection, binding to storage sites was not prominent, but for some hours afterward, specific localization in sharply defined regions of tissues was noted.

In the heart, long thin fibers, lying alongside myocardial cells, showed very intense labeling. In the spleen, short fibers in trabeculae and small "buttons" in splenic pulp appeared to be storage sites. In the small intestine, marked uptake of norepimephrine was observed in polymorphic masses scattered throughout the region of Auerbach's plexus, including those areas which could be demarcated as ganglia in this layer. In the kidney, storage of norepinephrine was occasionally observed in fibers at the vascular pole of some glomeruli. In the adrenal, the medulla became heavily labeled, while the cortex demonstrated no storage of norepinephrine.

It was concluded tentatively that the sites of norepinephrine storage in the tissues described were nerve endings of the sympathetic post-ganglionic system.