The stimulatory pathways controlling HCO3- secretion by the pancreatic ductal epithelium are well described. However, only a few data are available concerning inhibitory mechanisms, which may play an important role in the physiological control of the pancreas. The aim of this study was to investigate the cellular mechanism by which substance P (SP) inhibits pancreatic ductal HCO3- secretion. Sm...

Previous studies have shown that the middle third of the rat inner medullary collecting duct (IMCD-2) secretes protons despite the absence of intercalated cells, the cell thought to secrete protons in other portions of the collecting duct. A new cell, the IMCD cell, is the predominant cell in IMCD-2. The mechanism responsible for base exit in the IMCD cell was characterized by measuring cell pH...

Unidirectional [14C]HCO3- and 36Cl- efflux from human red cells and ghosts was studied under self-exchange conditions at pH 7.8 and 0 degrees C by means of the Millipore-Swinnex filtering technique. Control bicarbonate experiments showed that 14CO2 loss from the cells to the efflux medium was insignificant. The anion flux was determined under (a) symmetric variations of the anion concentration ...

Previous studies that have evaluated the Na(+)-H+ antiporter in cells from hypertensive subjects were generally performed under conditions in which HCO3-CO2, the physiological buffer system, was absent from the assay media. The objective of this study was to evaluate the activity of the Na(+)-H+ antiporter and that of the Na(+)-dependent and Na(+)-independent Cl(-)-HCO3- exchangers in cells ass...

Chronic metabolic acidosis increases urinary calcium excretion without altering intestinal calcium absorption, suggesting that bone mineral is the source of the additional urinary calcium. In vivo and in vitro studies have shown that metabolic acidosis causes a loss of mineral calcium while buffering the additional hydrogen ions. Previously, we studied changes in femoral, midcortical ion concen...

Intracellular pH (pHi) in squid giant axons recovers from acid loads by means of a Na(+)-dependent Cl-HCO3 exchanger, the actual mechanism of which might be exchange of: (i) external Na+ and HCO3- for internal Cl- and H+, (ii) Na+ plus two HCO3- for Cl-, (iii) Na+ and CO3= for Cl-, or (iv) the NaCO3- ion pair for Cl-. Here we examine sensitivity of transport to changes of extracellular pH (pHo)...

A 35-year-old transsexual (male to female) went to emergency with 24 h of mild fever, cough and dyspnoea. Four days before he had been submitted to multiple gluteus subcutaneous injections of polymethylmethacrylate (PMMA) microspheres. Patient had a past medical history of uncontrolled hypertension. On admission patient had Glasgow Coma Scale Score of 15, tachypnea and tachycardia, with central...

42 Abstract Background: Blood gas analysis is a widely used procedure. In clinical practice, the physicians may not always have a blood gas analyzer in their proximity. Not infrequently, blood gas samples are stored in a fridge or on ice and read retrospectively. Continued anaerobic and aerobic metabolism in the blood may alter blood gases in the interval between drawing arterial blood and its ...

abstract: this research was done to determine the effect of using l-carnitine and selected exercises on aerobic capacity and blood lactate. in this study 30 unathletes students of shahid rajaee university took part with the age of 22/63±1/75, height: 176 cm, weight 71/33±1 and bmi: 23/17±2/6. subjects randomly divided into 3 groups, control group who were doing the selected exercises, experimen...

The mechanism of basolateral membrane base transport was examined in the in vitro microperfused rabbit proximal convoluted tubule (PCT) in the absence and presence of ambient CO2/HCO3- by means of the microfluorometric measurement of cell pH. The buffer capacity of the cells measured using rapid NH3 washout was 42.8 +/- 5.6 mmol.liter-1.pH unit-1 in the absence and 84.6 +/- 7.3 mmol.liter-1.pH ...