scholarly journals Relationship between intracellular pH and proton mobility in rat and guinea-pig ventricular myocytes

2005 ◽  
Vol 566 (3) ◽  
pp. 793-806 ◽  
Author(s):  
Pawel Swietach ◽  
Richard D. Vaughan-Jones
Keyword(s):  
Guinea Pig ◽  
Intracellular Ph ◽  
Ventricular Myocytes ◽  
Proton Mobility

Na-independent Cl(-)-HCO3- exchange mediates recovery of pHi from alkalosis in guinea pig ventricular myocytes

1994 ◽  
Vol 267 (1) ◽  
pp. H85-H91 ◽  
Author(s):  
P. Xu ◽  
K. W. Spitzer
Keyword(s):  
Guinea Pig ◽  
Intracellular Ph ◽  
Ventricular Myocytes ◽  
Initial Rate ◽  
Ph Sensitive ◽  
Disulfonic Acid ◽  
Weak Base ◽  
External Application ◽  
Fluorescent Indicator ◽  
Ethanesulfonic Acid

The pH-sensitive fluorescent indicator, carboxy-seminaphthorhodafluor 1 (SNARF 1) was used to assess the contribution of forward Na-independent Cl(-)-HCO3- exchange (1 external Cl- exchanged for 1 internal HCO3-) to intracellular pH (pHi) recovery from alkalosis in adult ventricular myocytes (guinea pig). Intracellular alkalosis was elicited by external application of the weak base, trimethylamine. In the absence of CO2-HCO3- (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid-buffered solution) the initial rate of pHi recovery from alkalosis (pHi = 7.25-7.75) was slow and independent of pHi, yielding an apparent net HCO3- efflux of 0.36 +/- 0.11 mM/min. In CO2-HCO3(-)-buffered solution, the initial rate of pHi recovery and net HCO3- efflux were much faster and markedly increased by raising pHi. At pHi approximately 7.25, net HCO3- efflux was approximately 2 mM/min and rose to 9 mM/min at pHi approximately 7.6. 4,4'-Diisothiocyanostilbene-2,2'-disulfonic acid (0.4 mM) decreased net HCO3- efflux by 78.1 +/- 8.9% in CO2-HCO3(-)-buffered solution. Reduction in extracellular Cl- concentration from 135 to 20 mM markedly slowed the rate of pHi recovery from alkalosis and reduced net HCO3- efflux. pHi recovery from alkalosis was unaffected by removal of external sodium or exposure to 1 mM amiloride. These results indicate that forward Na-independent Cl(-)-HCO3- exchange mediates pHi recovery from alkalosis in guinea pig ventricular myocytes.

scholarly journals Temperature dependence of Na + −H + exchange, Na + −HCO 3 − co‐transport, intracellular buffering and intracellular pH in guinea‐pig ventricular myocytes

2003 ◽  
Vol 552 (3) ◽  
pp. 715-726 ◽  
Author(s):  
Frederick F.‐T. Ch'en ◽  
Emma Dilworth ◽  
Pawel Swietach ◽  
Ruth S. Goddard ◽  
Richard D. Vaughan‐Jones
Keyword(s):  
Guinea Pig ◽  
Temperature Dependence ◽  
Intracellular Ph ◽  
Ventricular Myocytes

Intracellular proton mobility and buffering power in cardiac ventricular myocytes from rat, rabbit, and guinea pig

2003 ◽  
Vol 285 (3) ◽  
pp. H1236-H1246 ◽  
Author(s):  
Massimiliano Zaniboni ◽  
Pawel Swietach ◽  
Alessandra Rossini ◽  
Taku Yamamoto ◽  
Kenneth W. Spitzer ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Ventricular Myocytes ◽  
Cardiac Cells ◽  
Proton Mobility ◽  
Mean Values ◽  
Common Value ◽  
Buffering Power ◽  
Apparent Diffusion ◽  
Best Fitting ◽  
Single Ventricular Myocytes

Intracellular pH (pHi) is an important modulator of cardiac function. The spatial regulation of pH within the cytoplasm depends, in part, on intracellular H+ ([Formula: see text]) mobility. The apparent diffusion coefficient for [Formula: see text], was estimated in single ventricular myocytes isolated from the rat, guinea pig, and rabbit. [Formula: see text] was derived by best-fitting predictions of a two-dimensional model of H+ diffusion to the local rise of intracellular [H+], recorded confocally (ratiometric seminaphthorhodafluor fluorescence) downstream from an acid-filled, whole cell patch pipette. Under [Formula: see text] conditions, [Formula: see text] was similar in all three species (mean values: 8–12.5 × 10–7 cm2/s) and was over 200-fold lower than that for H+ in water. In guinea pig myocytes, [Formula: see text] was increased 2.5-fold in the presence of [Formula: see text] buffer, in agreement with previous observations in rabbit myocytes. [Formula: see text] mobility is therefore low in cardiac cells, a feature that may predispose them to the generation of pHi gradients in response to sarcolemmal acid/base transport or local cytoplasmic acid production. Low [Formula: see text] mobility most likely results from H+ shuttling among cytoplasmic mobile and fixed buffers. This hypothesis was explored by comparing the pHi dependence of intrinsic, intracellular buffering capacity, measured for all three species, and subdividing buffering into mobile and fixed fractions. The proportion of buffer that is mobile will be the main determinant of [Formula: see text]. At a given pHi, this proportion appeared to be similar in all three species, consistent with a common value for [Formula: see text]. Over the pHi range of 6.0–8.0, the proportion is expected to change, predicting that [Formula: see text] may display some pHi sensitivity.

Effect of S20787, a novel Cl−-HCO3− exchange inhibitor, on intracellular pH regulation in guinea pig ventricular myocytes

2001 ◽  
Vol 8 (5) ◽  
pp. 395-405 ◽  
Author(s):  
Shih-Hurng Loh ◽  
Chien-Sung Tsai ◽  
Cheng-I Lin ◽  
Jong-Shiaw Jin ◽  
Richard D. Vaughan-Jones
Keyword(s):  
Guinea Pig ◽  
Intracellular Ph ◽  
Ventricular Myocytes ◽  
Ph Regulation ◽  
Intracellular Ph Regulation ◽  
Exchange Inhibitor

Effect of S20787, a Novel Cl–-HCO–3 Exchange Inhibitor, on Intracellular pH Regulation in Guinea Pig Ventricular Myocytes

2001 ◽  
Vol 8 (5) ◽  
pp. 395-405
Author(s):  
Shih-Hurng Loh ◽  
Chien-Sung Tsai ◽  
Cheng-I Lin ◽  
Jong-Shiaw Jin ◽  
Richard D. Vaughan-Jones
Keyword(s):  
Guinea Pig ◽  
Intracellular Ph ◽  
Ventricular Myocytes ◽  
Ph Regulation ◽  
Intracellular Ph Regulation ◽  
Exchange Inhibitor

scholarly journals Inhibition of Na-K pump current in guinea pig ventricular myocytes by dihydroouabain occurs at high- and low-affinity sites.

1989 ◽  
Vol 64 (6) ◽  
pp. 1063-1069 ◽  
Author(s):  
D J Mogul ◽  
H H Rasmussen ◽  
D H Singer ◽  
R E Ten Eick
Keyword(s):  
Guinea Pig ◽  
Ventricular Myocytes ◽  
Pump Current
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