Five to 6 wk after bilateral stellate ganglionectomy noradrenaline (NA) [norepinephrine] levels in cats'' atria were reduced to .apprx. 20% of controls. In vivo uptake of 3H-NA and of 35S-sulfate into gradient fractions containing noradrenergic vesicles from the atria decreased to .apprx. 30 and .apprx. 40%, respectively. The uptakes of 3H-NA and 35S-sulfate were significantly correlated in both control and ganglionectomized cats, and the distributions of 3H and 35S on the gradients were parallel. Sulfomucopolysaccharides (SMPS) may be localized in noradrenergic vesicles, possibly participating in the storage of NA. In 10 wk old rats treated neonatally with either 6-hydroxydopamine (6-OH-DA) or guanethidine, levels of NA in the heart, spleen and salivary glands were decreased to < 10% and to 10-20%, respectively; in the seminal ducts to 33 and 45%, respectively. 3H-NA uptake into noradrenergic-vesicle-enriched subcellular fractions from the heart, spleen and salivary glands of 6-OH-DA treated rats decreased almost to the extent of NA depletion but in the seminal ducts the decrease was less marked. Guanethidine treatment left the uptake unaffected, except for the spleen. The discrepancy between storage and uptake suggests that surviving neurons display during their outgrowth into tissues a high uptake capacity but lack full NA synthesis. 35S-sulfate incorporation into non-lipid compounds, presumably SMPS, in the noradrenergic-vesicle-enriched fractions appeared unaffected or increased over corresponding control levels, possibly due to high synthetic activity in the growing neurons.