Measurement of Intracellular pH.

The activity of most cellular processes is sensitive to pH. Cells therefore tightly control cytosol pH within narrow bounds. Measurement of cytosolic pH is of interest in studying many processes, including pH regulatory transport proteins.

Survey on current hydrotherapy use among North American burn centers.

The authors have reviewed hydrotherapy practices in North American burn centers and described the epidemiology of hydrotherapy-associated nosocomial infections. A web-based survey was distributed to the directors of all burn care facilities listed by the American Burn Association. Questions addressed aspects of practice, including the method, additives, disposable liners, decontamination practices, nosocomial pathogens, and perceptions regarding the "ideal" method of hydrotherapy.

The bicarbonate transport metabolon.

To allow cells to control their pH and bicarbonate levels, cells express bicarbonate transport proteins that rapidly and selectively move bicarbonate across the plasma membrane. Physical interactions have been identified between the carbonic anhydrase isoform, CAII, and the erythrocyte membrane Cl- /HCO3(-) anion exchanger, AE1, mediated by an acidic motif in the AE1 C-terminus. We have found that the presence of CAII attached to AE1 accelerates AE1 HCO3(-) transport activity, as AE1 moves bicarbonate either into or out of the cell.

Regulation of the human NBC3 Na+/HCO3- cotransporter by carbonic anhydrase II and PKA.

Human NBC3 is an electroneutral Na(+)/HCO(3)(-) cotransporter expressed in heart, skeletal muscle, and kidney in which it plays an important role in HCO(3)(-) metabolism. Cytosolic enzyme carbonic anhydrase II (CAII) catalyzes the reaction CO(2) + H(2)O left arrow over right arrow HCO(3)(-) + H(+) in many tissues. We investigated whether NBC3, like some Cl(-)/HCO(3)(-) exchange proteins, could bind CAII and whether PKA could regulate NBC3 activity through modulation of CAII binding.

Structural and functional characterization of the human NBC3 sodium/bicarbonate co-transporter carboxyl-terminal cytoplasmic domain.

The sodium bicarbonate co-transporter, NBC3, is expressed in a range of tissues including heart, skeletal muscle and kidney, where it modulates intracellular pH and bicarbonate levels. NBC3 has a three-domain structure: 67 kDa N-terminal cytoplasmic domain, 57 kDa membrane domain and an 11 kDa C-terminal cytoplasmic domain (NBC3Ct). The role of C-terminal domains as important regulatory regions is an emerging theme in bicarbonate transporter physiology.

Direct extracellular interaction between carbonic anhydrase IV and the human NBC1 sodium/bicarbonate co-transporter.

Sodium/bicarbonate co-transporters (NBC) are crucial in the regulation of intracellular pH (pH(i)) and HCO(3)(-) metabolism. Electrogenic NBC1 catalyzes HCO(3)(-) fluxes in mammalian kidney, pancreas, and heart cells. Carbonic anhydrase IV (CAIV), which is also present in these tissues, is glycosylphosphatidyl inositol-anchored to the outer surface of the plasma membrane where it catalyzes the hydration-dehydration of CO(2)/HCO(3)(-).

Transport activity of chimaeric AE2-AE3 chloride/bicarbonate anion exchange proteins.

Chloride/bicarbonate anion exchangers (AEs), found in the plasma membrane of most mammalian cells, are involved in pH regulation and bicarbonate metabolism. Although AE2 and AE3 are highly similar in sequence, AE2-transport activity was 10-fold higher than AE3 (41 versus 4 mM x min(-1) respectively), when expressed by transient transfection of HEK-293 cells. AE2-AE3 chimaeras were constructed to define the region responsible for differences in transport activity.