Immunocytochemical localization of Na+/K+-ATPase and V-H+-ATPase in the salivary glands of the cockroach,Periplaneta americana |
| |
Authors: | Frank Just Bernd Walz |
| |
Affiliation: | (1) Institut für Zoologie der Universität, Universitätsstrasse 31, D-93040 Regensburg, Germany |
| |
Abstract: | The acinous salivary glands of the cockroach (Periplaneta americana) consist of four morphologically different cell types with different functions: the peripheral cells are thought to produce the fluid component of the primary saliva, the central cells secrete the proteinaceous components, the inner acinar duct cells stabilize the acini and secrete a cuticular, intima, whereas the distal duct cells modify the primary saliva via the transport of water and electrolytes. Because there is no direct information available on the distribution of ion transporting enzymes in the salivary glands, we have mapped the distribution of two key transport enzymes, the Na+/K+-ATPase (sodium pump) and a vacuolar-type H+-ATPase, by immunocytochemical techniques. In the peripheral cells, the Na+/K+-ATPase is localized to the highly infolded apical membrane surface. The distal duct cells show large numbers of sodium pumps localized to the basolateral part of their plasma membrane, whereas their highly folded apical membranes have a vacuolar-type H+-ATPase. Our immunocytochemical data are supported by conventional electron microscopy, which shows electrondense 10-nm particles (portasomes) on the cytoplasmic surface of the infoldings of the apical membranes of the distal duct cells. The apically localized Na+/K+-ATPase in the peripheral cells is probably directly involved in the formation of the Na+-rich primary saliva. The latter is modified by the distal duct cells by transport mechanisms energized by the proton motive force of the apically localized V-H+-ATPase. |
| |
Keywords: | Salivary glands Na+/K+-ATPase H+-ATPase Epithelial transport Polarity Immunocytochemistry Periplaneta americana (Insecta) |
本文献已被 SpringerLink 等数据库收录! |
|