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Non-neurogenic adrenal catecholamine release in the neonatal rat: Exocytosis or diffusion?

1986; Elsevier BV; Volume: 28; Issue: 2 Linguagem: Inglês

10.1016/0165-3806(86)90031-3

1872-6755

Frederic J. Seidler, Theodore A. Slotkin,

Neuroendocrine regulation and behavior

When subjected to stress, neonatal rats secrete adrenal catecholamines by a mechanism which does not require nerve stimulation. To test whether the non-neurogenic secretory mechanism involves exocytosis, we examined the effects of hypoxia (a non-neurogenic stimulus) and nicotine (a stimulus which simulates neurogenic input) on catecholamine levels and on the uptake of [3H]epinephrine into chromaffin granules. Hypoxia- and nicotine-induced depletion of catecholamines were both accompanied by a reduction in uptake, indicating a loss of granule integrity which is characteristic of exocytosis. Although a significant proportion of adrenal catecholamines was found to be extragranular, only the granular pool was involved in the secretory response.