Storage and Release of Noradrenaline in Hypothalamic Synaptosomes

Abstract: The noradrenaline storage capacity of vesicles in hypothalamic synaptosomes was measured by incubating them with ³H]noradrenaline under saturating conditions. The normal noradrenaline content is 52% of storage capacity. Incubation or superfusion with 50 mm -potassium causes calcium-dependent release from the vesicles. Such release reduces not only the vesicular content, but also the noradrenaline storage capacity. This suggests that after exocytosis vesicles cannot refill with noradrenaline.