FROM COILED TUBULES TO A SECRETORY CANALICULUS - A NEW MODEL FOR MEMBRANE TRANSFORMATION AND ACID-SECRETION BY GASTRIC PARIETAL-CELLS

The acid-secreting gastric parietal cell has a unique secretory membra ne system. This membrane system exists in an inactive (non-secreting) and an active (secreting) form. The current accepted model to explain the transformation events associated with the conversion of the non-s ecreting membrane to the secreting membrane, and vice versa, invokes m embrane recycling of elongated vesicle structures. However, recent stu dies employing cryopreparation have shown that the non-secreting membr ane in these cells is actually a complex network of helically coiled t ubules. Here, we present an alternative model to explain how the membr ane in parietal cells is activated to secrete HCl.