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Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1977 Sep;74(9):4068–4072. doi: 10.1073/pnas.74.9.4068

Transport of alpha-amylase across the basolateral membrane of the pancreatic acinar cell.

L D Isenman, S S Rothman
PMCID: PMC431848  PMID: 302947

Abstract

The flux of alpha-amylase (1,4-alpha-D-glucan glucanohydrolase; EC 3.2.1.1) across the basolateral membrane of the acinar cell was measured in the cell-to-bath direction using the whole rabbit pancreas in organ culture. This in vitro preparation is polarized so that apical and basolateral secretions can be collected separately. The unstimulated amylase flux from cell to bath was substantial at the initial rate (approximately three times the concurrent apical flux). With time, bath amylase approached a steady-state concentration, suggesting an equilbrating process. During the same time interval, ductal amylase secretion remained constant. At the steady state, the amylase concentration in the bath was at least an order of magnitude less than its ductal concentration. Hourly replacement of bathing medium reproduced the initial rate of amylase release into the bath for five consecutive hours. Pancreozymin (cholecystokinin), a peptide hormone, did not alter the steady-state bath amylase content, although it greatly augmented ductal amylase secretion. In contrast, a cholinergic agonist greatly increased both the flux from the cell to bath and the ductal secretion of amylase. Taken together, these results indicate a natural bidirectional permeability of the basolateral membrane to digestive enzyme and support evidence previously obtained suggesting that such a permeability might exist.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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