Modified smooth endoplasmic reticulum in type II cells of rabbit taste buds.

Type II cells of taste buds from rabbit foliate papillae are characterized by a widespread system of smooth endoplasmic reticulum (SER), usually in the form of a loose network. In some cells, the SER is tightly compacted into a juxtanuclear aggregate that is continuous with the perinuclear space and that appears to merge with the Golgi complex. In other type II cells, the SER is in a honeycomb arrangement. Where type II cells confront nerves, they may have extensive smooth-membraned subsurface cisternae. The presence of manifold forms of SER in type II cells suggests that these cells may have a variety of secretory functions.