Intracellular pH responses of hybridoma and yeast to substrate addition and acid challenge.
The pHi responses of hybridoma and yeast cells to substrate and external acid additions were measured using the fluorescent pHi indicator, 9-aminoacridine. The pHi change, following CCCP addition, indicated by 9AA, compared very well with that indicated by BCECF. No change in pHi was observed following glucose or glutamine additions to hybridoma cells under glucose- and glutamine-absent conditions. Also, no change in pHi was observed when glucose was added in the presence of low glutamine and when glutamine was added in the presence of low glucose. However, in the presence of amiloride, the pHi of hybridoma cells decreased following glucose addition. Intracellular pH responses of hybridoma and yeast cells to decreases in external pH, effected by acid addition, were dependent on the cellular energy state and acid type. Cells controlled their pHi more tightly under energy-poor conditions compared to energy-rich conditions, and sulfuric acid (strong acid) caused larger changes in pHi compared to pyruvic acid (weak acid). In response to acid addition under energy-rich conditions, the magnitudes of pHi increases in hybridoma were smaller in the presence of amiloride compared to that in the absence of amiloride. Further, pHi responses to a decrease in external pH were slower at submetabolic temperatures.
Department of Chemical Engineering, Drexel University, Philadelphia, Pennsylvania 19104.
G K
GK
Sureshkumar
R
R
Mutharasan
D000143:Acids / Q000494:pharmacology*; D000584:Amiloride / Q000494:pharmacology; D000585:Aminacrine / Q000378:metabolism; D000818:Animals; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002951:Citrates / Q000494:pharmacology; D019343:Citric Acid; D003470:Culture Media / Q000494:pharmacology*; D005452:Fluoresceins / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D005470:Fluorometry; D005656:Fungal Proteins / Q000378:metabolism; D006825:Hybridomas / Q000187:drug effects* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007424:Intracellular Fluid / Q000378:metabolism*; D051379:Mice; D011773:Pyruvates / Q000494:pharmacology; D019289:Pyruvic Acid; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013464:Sulfuric Acids / Q000494:pharmacology; D013696:Temperature
D000143:Acids; D002951:Citrates; D003470:Culture Media; D005452:Fluoresceins; D005456:Fluorescent Dyes; D005656:Fungal Proteins; D011773:Pyruvates; D017923:Sodium-Hydrogen Exchangers; D013464:Sulfuric Acids; D019343:Citric Acid; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D000585:Aminacrine; D000584:Amiloride; C043829:2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein; D019289:Pyruvic Acid; D000254:Sodium-Potassium-Exchanging ATPase; C033158:sulfuric acid