The effects of systemic bicarbonate concentration and extracellular fluid volume status on proximal tubular bicarbonate absorption, independent of changes in luminal composition and flow rate, were examined with in vivo luminal microperfusion of rat superficial proximal convoluted tubules. Net bicarbonate absorption and bicarbonate permeability were measured using microcalorimetry. From these d...

Many cystic fibrosis transmembrane conductance regulator (CFTR)-expressing epithelia secrete bicarbonate (HCO(3)(-))-containing fluids. Recent evidence suggests that defects in epithelial bicarbonate secretion are directly involved in the pathogenesis of cystic fibrosis, in particular by building up hyperviscous mucus in the ductal structures of the lung and pancreas. Pancreatic juice is one of...

purpose: to investigate the effects of sodium bicarbonate (nahco3) on exhaustive activity and physiological parameters of fatigue in conscripts. materials and methods: thirty conscripts did wingate test in two groups: sodium bicarbonate group (treatment) and placebo (control) group. in both groups, sodium bicarbonate (0.3 g/kg of body mass) or placebo was ingested 60 minutes before the training...

this experiment was conducted using 216 male chicken (ross 308) to evaluate the effects of organic selenium and sodium bicarbonate supplementation on blood parameters, growth performance and carcass characteristics in heat stress condition. birds were reared under same condition and fed with similar diets till 28 d of age. at 28 days of old, broiler with similar weight were regrouped within die...

The effect of volume absorption on bicarbonate absorption was examined in the in vivo perfused rat proximal convoluted tubule. Volume absorption was inhibited by isosmotic replacement of luminal NaCl with raffinose. In tubules perfused with 25 mM bicarbonate, as raffinose was increased from 0 to 55 to 63 mM, volume absorption decreased from 2.18 +/- 0.10 to 0.30 +/- 0.18 to -0.66 +/- 0.30 nl/mm...

conclusions in samples stored in plastic syringes, overestimation of pao2 levels should be noted if samples cooled before analysis. in samples stored in plastic syringes, it is not necessary to store samples in iced water when analysis delayed up to one hour. results pao2 of the samples stored at 0°c was increased significantly after 60 minutes (p = 0.007). the paco2 of the samples kept for 30 ...

Bicarbonate reabsorption is classically regarded as a rate-limited process characterized by saturation kinetics. The tubular maximum (Tm), however, varies with glomerular filtration rate. Thus bicarbonate reabsorption, in common with sodium reabsorption, is characterized by glomerulo-tubular balance. The examination of bicarbonate reabsorption is accomplished using the bicarbonate titration tec...