Disposition of norepinephrine-H3 in sympathetic ganglia.

Injected H 3 -norepinephrine is rapidly taken up by superior cervical ganglia and rapidly disappears at a monophasic rate with a half-life of about 1 hour. Denervation of the superior cervical ganglia markedly slows this rate of disappearance. The ganglionic stores of H 3 -norepinephrine can be depleted by reserpine treatment but not by tyramine. The uptake of H 3 -norepinephrine in sympathetic ganglia is unaffected by pretreatment with cocaine. Both endogenous and exogenous catecholamines in the superior cervical ganglia are localized in the cytoplasm. Considerable activities of catechol-O-methyl transferase, histamine methyl transferase, monoamine oxidase, and 5-hydroxytryptophan decarboxylase can be demonstrated in superior cervical ganglia.