Hormones of the Adrenal Medulla

Nicotinic Receptors in Human Chromaffin Cells: Characterization, Functional and Physical Interactions between Subtypes and Regulation

“…The entry of Na + through channels depolarizes the plasma membrane, increasing the probability of voltage-Ca 2+ channels opening. This entry of Ca 2+ , which also induces the release of Ca 2+ stored in intracellular stores, is ultimately responsible for the fusion of mature secr vesicles with the plasma membrane through a process of exocytosis, releasing their tent of catecholamines into the bloodstream [25] (Figure 2). The Ca 2+ -dependent synaptic connection between splanchnic nerve terminals and chromaffin cells is known as "excitation-secretion coupling", a term adapted by Douglas and Rubin (1961) [23] from the one coined by Sandow in 1952 [24] after their observations in skeletal muscle.…”

“…The entry of Na + through these channels depolarizes the plasma membrane, increasing the probability of voltage-gated Ca 2+ channels opening. This entry of Ca 2+ , which also induces the release of Ca 2+ itself stored in intracellular stores, is ultimately responsible for the fusion of mature secretory vesicles with the plasma membrane through a process of exocytosis, releasing their content of catecholamines into the bloodstream [25] (Figure 2). Chromaffin cells share a large number of functional characteristics with sympathetic neurons because they have the same embryonic origin.…”