Effect of extracellular pH on cytoplasmic pH and mechanism of pH regulation in cultured bovine corneal endothelium: Possible importance in drug transport studies

1991 ◽  
Vol 68 (1-3) ◽  
pp. 231-238
Author(s):  
Martin E. Dowty ◽  
Pierre Braquet
Keyword(s):  
Corneal Endothelium ◽  
Drug Transport ◽  
Ph Regulation ◽  
Extracellular Ph ◽  
Cytoplasmic Ph ◽  
Transport Studies

Cytoplasmic pH regulation in phorbol ester-activated human neutrophils

1986 ◽  
Vol 251 (1) ◽  
pp. C55-C65 ◽  
Author(s):  
S. Grinstein ◽  
W. Furuya
Keyword(s):  
Metabolic Pathways ◽  
Phorbol Esters ◽  
Ph Regulation ◽  
Human Neutrophils ◽  
Hexose Monophosphate ◽  
Cytoplasmic Ph ◽  
Extracellular Acidification ◽  
Hexose Monophosphate Shunt ◽  
Activated Neutrophils ◽  
Cytoplasmic Acidification

Activation of neutrophils by 12-O-tetradecanoylphorbol-13-acetate (TPA) is accompanied by an initial cytoplasmic acidification, followed by an alkalinizing phase due to Na+-H+ countertransport. The source of the acidification, which is fully expressed by activation with TPA in Na+-free or amiloride-containing media, was investigated. The acidification phase was detected also in degranulated and enucleated cytoplasts, ruling out a major contribution by the nucleus or secretory vesicles. Cytoplasmic acidification was found to be associated with an extracellular acidification, suggesting metabolic generation of H+. Two principal metabolic pathways are stimulated in activated neutrophils: the reduction of O2 by NADPH-oxidase and the hexose monophosphate shunt. A good correlation was found between the activity of these pathways and the changes in cytoplasmic pH. Inhibition of superoxide synthesis prevented the TPA-induced cytoplasmic acidification. Moreover, activation of the hexose monophosphate shunt with permeable NADPH-oxidizing agents (in the absence of TPA) also produced a cytoplasmic acidification. Cytoplasmic acidification was also elicited by exogenous diacylglycerol and by other beta-phorbol diesters, which are activators of the kinase, but not by unesterified phorbol or by alpha-phorbol diesters, which are biologically inactive. The results suggest that the cytoplasmic acidification induced by phorbol esters in neutrophils reflects accumulation of H+ liberated during the metabolic burst that follows activation.

scholarly journals A Monolayer of Primary Colonic Epithelium Generated on a Scaffold with a Gradient of Stiffness for Drug Transport Studies

2018 ◽  
Vol 90 (22) ◽  
pp. 13331-13340 ◽  
Author(s):  
Dulan B. Gunasekara ◽  
Jennifer Speer ◽  
Yuli Wang ◽  
Daniel L. Nguyen ◽  
Mark I. Reed ◽  
...  
Keyword(s):  
Drug Transport ◽  
Colonic Epithelium ◽  
Transport Studies

scholarly journals The Influence of Age on pH Regulation in Hippocampal Slices Before, During, and after Anoxia

1997 ◽  
Vol 17 (5) ◽  
pp. 560-566 ◽  
Author(s):  
Eugene L. Roberts ◽  
Ching-Ping Chih
Keyword(s):  
Brain Tissue ◽  
Intracellular Ph ◽  
Ph Regulation ◽  
Hippocampal Slices ◽  
Extracellular Ph ◽  
Aged Brain ◽  
Age Related ◽  
Anoxic Depolarization ◽  
Rate Of Recovery ◽  
Old Rats

Changes in intracellular and extracellular pH may influence the vulnerability of brain tissue to anoxic or ischemic damage. In the present study, we investigated whether the increased vulnerability of aged brain tissue to anoxic damage is associated with age-related alterations in pH regulation. We obtained evidence for altered pH regulation by measuring concurrent changes in intracellular and extracellular pH before, during, and after anoxia in hippocampal slices from young adult (6–8 months old) and aged (24–27 months old) rats. We found indications of impaired pH regulation in aged hippocampal slices (a) before anoxia, as seen in a lower resting intracellular pH, (b) during anoxia, as seen in a slower decline in extracellular pH, and (c) during recovery after anoxia, as seen in a slower rate of recovery of intracellular pH. Age-related changes in pH regulation may contribute to the faster onset of anoxic depolarization in aged brain tissue during anoxia.

scholarly journals 3D Printed Stackable Titer Plate Inserts Supporting Three Interconnected Tissue Models for Drug Transport Studies

2020 ◽  
Vol 4 (7) ◽  
pp. 1900289
Author(s):  
Morten Leth Jepsen ◽  
Andreas Willumsen ◽  
Chiara Mazzoni ◽  
Anja Boisen ◽  
Line Hagner Nielsen ◽  
...  
Keyword(s):  
Drug Transport ◽  
Transport Studies ◽  
3D Printed ◽  
Tissue Models
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