Na+ channel inactivation: a comparative study between pancreatic islet beta-cells and adrenal chromaffin cells in rat.

A comparative study was carried out on the inactivation of Na+ channels in two types of endocrine cells in rats, beta-cells and adrenal chromaffin cells (ACCs), using patch-clamp techniques. The beta-cells were very sensitive to hyperpolarization; the Na+ currents increased ninefold when the holding potential was shifted from -70 mV to -120 mV. ACCs were not sensitive to hyperpolarization.

[A brief introduction to the secretion mechanism in immunocytes].

Exocytosis is a vital function of many cell types including neuron, endocrine cell and immunocyte. Secretion in immunocytes involves a complex process of signal transduction, in which many factors still remain unknown. In the last 10 years, this area has become an international hot spot of investigation, resulting in many break-through progresses.