Abstract
Brush border membrane vesicles have been used to study the regulation of rat duodenal HCO3 secretion. When vesicles were loaded with cAMP and ATP SITS-sensitive Cl/HCO3 exchange (unidirectional 36Cl influx in response to an outward-facing OH/HCO3 gradient) was stimulated by approximately 25%. In contrast, there was no effect of cAMP upon SITS-insensitive 36Cl uptake. The stimulation of Cl/HCO3 exchange caused by cAMP was abolished in the presence of a specific heat-stable cAMP-dependent protein kinase inhibitor. These results suggest that Cl/HCO3 exchange, and hence HCO3 secretion, is regulated by cAMP via phosphorylation of some component of the membrane associated with the transport protein.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have