UNLABELLED To study the regulation of cell pH by ambient pH, carbon dioxide tension (PCO2), and bicarbonate (HCO3), cell pH was measured in the isolated, in vitro microperfused rabbit proximal convoluted tubule using the fluorescent dye (2',7')-bis-(carboxyethyl)-(5,6)-carboxyfluorescein. For the same changes in external pH, changes in [HCO3] and PCO2 affected cell pH similarly ([HCO3]: pHi/pHe...

2/3 of the reservoir surface area was approximately covered with dense populations of Myriophyllum, Ceratophyllum and Potamogeton species. The headwaters of the reservoir were considered as hard water and had both carbonatic and non-carbonatic hardness. When they were exposed to lentic condition of the reservoir and its intensive photosynthetic activities of macrophyte communities, the bicarbon...

Colonic bicarbonate (HCO3(-)) secretion is a well-established physiological process that is closely linked to overall fluid and electrolyte movement in the mammalian colon. These present studies show that extracellular calcium-sensing receptor (CaSR), a fundamental mechanism for sensing and regulating ionic and nutrient compositions of extracellular milieu in the small and large intestine, regu...

OBJECTIVE To investigate whether serum bicarbonate (HCO3) levels can be used to accurately diagnose diabetic ketoacidosis (DKA) and classify its severity in children with new-onset diabetes mellitus (NODM). METHODS Retrospective study of all patients with NODM presenting to Boston Children's Hospital from October 1, 2007, to July 1, 2013. DKA was defined as blood glucose ≥200 mg/dL, venous pH...

Studies were undertaken to define the pattern of proximal tubular bicarbonate reabsorption and its relation to tubular and capillary PCO2 in rats with chronic metabolic alkalosis (CMA). CMA was induced by administering furosemide to rats ingesting a low electrolyte diet supplemented with NaHCO3 and KHCO3. Proximal tubular bicarbonate reabsorption and PCO2 were measured in CMA rats either 4-7 or...

METABOLIC ACIDOSIS, TRADITIONALLY defined as a reduction in serum HCO3 concentration ([HCO3 ]) often associated with a detectable reduction in blood pH, is a common accompaniment of progressive chronic kidney disease (CKD) (7). The metabolic acidosis even when mild is not without consequences: increased degradation of muscle protein with muscle wasting (1), reduced albumin synthesis with result...

The role of Slc26a6 (PAT1) on apical Cl-/HCO3- exchange and bicarbonate secretion in pancreatic duct cells was investigated using Slc26a6 null and wild-type (WT) mice. Apical Cl-/HCO3- exchange activity was measured with the pH-sensitive dye BCECF in microperfused interlobular ducts. The HCO3(-)-influx mode of apical [Cl-]i/[HCO3-]o exchange (where brackets denote concentration and subscripts i...

Studies were performed on canine cardiac Purkinje fibers to evaluate the effects of acidosis and bicarbonate (HCO3) on action potential repolarization. Extracellular pH (pHe) was reduced from 7.4 to 6.8 by increasing carbon dioxide (CO2) concentration from 4 to 15% in a HCO3-buffered solution or by NaOH titration in a Hepes-buffered solution. Both types of acidosis produced a slowing of the rat...

Calcareous soils are characterized by low nutrient contents, high bicarbonate (HCO3-) content, and high alkalinity. The effects of HCO3- addition under zinc-sufficient (+Zn) and zinc-deficient (-Zn) conditions on the growth and photosynthetic characteristics of seedlings of two Moraceae species (Broussonetia papyrifera and Morus alba) and two Brassicaceae species (Orychophragmus violaceus and B...

Bicarbonate plays an important role in airway host defense, however, its transport mechanisms remain uncertain. Here we examined the relative contributions of the anion channel CFTR (cystic fibrosis transmembrane conductance regulator, ABCC7) and the anion exchanger pendrin (SLC26A4) to HCO3- secretion by the human airway cell line Calu-3. Pendrin and CFTR were both detected in parental Calu-3 ...