Die Bedeutung der HCO 3 ? -ATPase in der H+/HCO 3 ? -Sekretion

Abstract

Active buffer transport, e.g. H+ -secretion by stomach and kidney and HCO3--secretion by pancreas and salivary glands, is linked with the presence of a HCO3-stimulated ATP-Phosphohydrolase. In contrast to (Na+ -k+)-ATPase which is considered to be equivalent to the Na+ pump, the HCO3--ATPase requires only one ion for activation and is insensitive to ouabain. The HCO3--ATPase is found in the plasma membrane of the epithelia, but in contrast to the (Na+ -k+)-ATPase it is located in the luminal cell border. The activity of the HCO3--ATPase changes in parallel along with the rate of active buffer transport, a finding which underlines its importance as a transport enzyme. Several disorders of buffer transport are described which are possibly associated with a defect of the HCO3--ATPase system.

The Resource-Based View Within the Conversation of Strategic Management

“…An advantage of the disequilibrium approach is that time may be viewed as the fourth dimension of resources (along with land, labor, and capital, broadly defined). Time and attention are scarce resources (Simon, 1976) and are sources of competitive advantage that are neglected in single-period equilibrium analysis.…”