Stress-induced degranulation accompanied by vesicle formation in the adrenal chromaffin cells of the mouse.

Stress was induced in mice by restraining on a board by pinning their limbs followed by immersion of the hind feet in a water bath of 20 degrees C. Fine structure of adrenal chromaffin cells was studied by light and electron microscopy. After 8 to 22 hrs' stress, remarkable decrease in the number of argentaffin granules of the NA cells was demonstrated by light microscopy. By electron microscopy, the decline in the granule number was marked in A, NA and SGC cells. This degranulation was accompanied by theoccurrence of numerous smally cytoplasmic vesicles which often appeared empty but sometimes contained an electron-dense material. Granule-containing invaginations of plasma membrane were frequently seen and were interpreted to represent the exocytotis profiles. The idea that the secretory granule membrane and associated substances might be recovered in the form of cytoplasmic vesicles was thus supported. Exposure of the mouse to restraint plus water immersion stress proved to be a simple method for production of acute and drastic degranulation of the adrenal chromaffin cells.