Previous micropuncture studies supporting hydrogen secretion as the mechanism of bicarbonate reabsorption have relied on the demonstration of an acid disequilibrium pH in the proximal tubule after systemic administration of a carbonic anhydrase inhibitor. Previous calculations of disequilibrium pH, however, have involved the necessary assumption that PCO2 in the proximal convoluted tubule was e...

The US South Atlantic Bight (SAB) is a lowlatitude shallow continental shelf bordered landward by abundant salt marshes and rivers. Based on previously published data on sea surface partial pressure of carbon dioxide (pCO2) and new dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) data, a model analysis is presented to identify and quantify the contributions of various terrest...

Negative arterial to end-tidal pco2 differences ((a-ET)pco2) have been reported in normoxia. To determine the influence of blood temperature on (a-ET)pco2, 11 volunteers (21 ± 2 years) performed incremental exercise to exhaustion in normoxia (Nx, Pio2: 143 mmHg) and hypoxia (Hyp, Pio2: 73 mmHg), while arterial blood gases and temperature (ABT) were simultaneously measured together with end-tida...

Elevated pCO2 threatens coral reefs through impaired calcification. However, the extent to which elevated pCO2 affects the distribution of the pelagic larvae of scleractinian corals, and how this may be interpreted in the context of ocean acidification (OA), remains unknown. We tested the hypothesis that elevated pCO2 affects one aspect of the behavior (i.e., motility) of brooded larvae from Po...

Increases in tissue partial pressure of carbon dioxide (PCO2) can reflect an abnormal oxygen supply to the cells, so that monitoring tissue PCO2 may help identify circulatory abnormalities and guide their correction. Gastric tonometry aims at monitoring regional PCO2 in the stomach, an easily accessible organ that becomes ischemic quite early when the circulatory status is jeopardized. Despite ...

Precambrian atmospheric pCO2 levels were previously estimated using a simple thermodynamic model based on the mineral assemblage in paleosols. In addition to theoretical flaws with that model, recalculation of pCO2 levels using more recent thermodynamic data gives significantly lower values. A new model based on the mass balance of weathering in paleosols gives consistent results from three sep...

The Bering Sea, one of the largest and most productive marginal seas, is a crucial carbon sink for the marine carbonate system. However, restricted by the tough observation conditions, few underway datasets of sea surface partial pressure of carbon dioxide (pCO2) have been obtained, with most of them in the eastern areas. Satellite remote sensing data can provide valuable information covered by...

Inhibition of carbonic anhydrase (CA) activity (activity in red blood cells and activity available on capillary endothelium) results in decrements in CO2 excretion (VCO2) and plasma-erythrocyte CO2-HCO(-3)-H+ disequilibrium as blood travels around the circulation. To investigate the kinetics of changes in blood PCO2 and pH during progressive CA inhibition, we used our previously detailed mathem...

We are starting to understand the relationship between metabolic rate responses and species' ability to respond to exposure to high pCO2. However, most of our knowledge has come from investigations of single species. The examination of metabolic responses of closely related species with differing distributions around natural elevated CO2 areas may be useful to inform our understanding of their ...

Ocean acidification poses a severe threat to corals; declines in carbonate ion concentrations caused by increasing atmospheric CO2 partial pressure (pCO2) can severely impact coral calcification. Thus, there is an urgent need understand the impacts of near-future ocean on corals. In this study, we compared effects seawater at present and pCO2 (approximately +200 μatm) levels skeletal weights ne...