Effect of nitric oxide donors S-nitroso-N-acetyl-DL-penicillamine, spermine NONOate and propylamine propylamine NONOate on intracellular pH in cardiomyocytes. Clin Exp Pharmacol Physiol 2012 Sep;39(9):772-8
Date
06/19/2012Pubmed ID
22703333Pubmed Central ID
PMC3430815DOI
10.1111/j.1440-1681.2012.05734.xScopus ID
2-s2.0-84865595451 (requires institutional sign-in at Scopus site) 10 CitationsAbstract
1. Previous studies suggest that exogenous nitric oxide (NO) and NO-dependent signalling pathways modulate intracellular pH (pH(i)) in different cell types, but the role of NO in pH(i) regulation in the heart is poorly understood. Therefore, in the present study we investigated the effect of the NO donors S-nitroso-N-acetyl-DL-penicillamine, spermine NONOate and propylamine propylamine NONOate on pH(i) in rat isolated ventricular myocytes. 2. Cells were isolated from the hearts of adult Wistar rats and pH(i) was monitored using the pH-sensitive fluorescent indicator 5-(and-6)-carboxy seminaphtharhodafluor (SNARF)-1 (10 μmol/L) and a confocal microscope. To test the effect of NO donors on the Na⁺/H⁺ exchanger (NHE), basal pH(i) in Na⁺-free buffer and pH(i) recovery from intracellular acidosis after an ammonium chloride (10 mmol/L) prepulse were monitored. The role of carbonic anhydrase was tested using acetazolamide (50 μmol/L). 4,4-Diisothiocyanatostilbene-2,2'-disulphonic acid (0.5 mmol/L; DIDS) was used to inhibit the Cl⁻/OH⁻ and Cl⁻/HCO₃-exchangers. Acetazolamide and DIDS were applied via the superfusion system 1 and 5 min before the NO donors. 3. All three NO donors acutely decreased pH(i) and this effect persisted until the NO donor was removed. In Na⁺-free buffer, the decrease in basal pH(i) was increased, whereas inhibition of carbonic anhydrase and Cl⁻/OH⁻ and Cl⁻/HCO₃⁻ exchangers did not alter the effects of the NO donors on pH(i). After an ammonium preload, pH(i) recovery was accelerated in the presence of the NO donors. 4. In conclusion, exogenous NO decreases basal pH(i), leading to increased NHE activity. Carbonic anhydrase and chloride-dependent sarcolemmal HCO₃⁻ and OH⁻ transporters are not involved in the NO-induced decrease in pH(i) in rat isolated ventricular myocytes.
Author List
Pravdic D, Vladic N, Cavar I, Bosnjak ZJMESH terms used to index this publication - Major topics in bold
Ammonium ChlorideAnimals
Antiporters
Carbonic Anhydrase Inhibitors
Carbonic Anhydrases
Cells, Cultured
Fluorescent Dyes
Hydrazines
Hydrogen-Ion Concentration
Intracellular Fluid
Male
Membrane Transport Modulators
Microscopy, Confocal
Myocytes, Cardiac
Nitric Oxide
Nitric Oxide Donors
Rats
Rats, Wistar
S-Nitroso-N-Acetylpenicillamine
Sodium-Hydrogen Exchangers
Spermine