pH regulation in adult cardiac myocytes

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6622276

Wallert, M A

The purpose of this study is to examine the pH{sub i} regulatory mechanisms of adult ventricular myocytes, the cells that perform the pumping work of the heart. The cell system for this study was the ventricular myocyte, isolated by enzymatic dissociation from adult rate heart. In agreement with the findings on other cardiac model cells, I demonstrated the existence of a Cl{sup {minus}}/HCO{sub 3}{sup {minus}} exchanger and a Na{sup +}/H{sup +} exchanger in ventricular myocytes. The existence of the anion exchanger was demonstrated in {sup 36}Cl{sup {minus}} flux experiments and as stilbene disulfonate-inhibitable and Cl{sup {minus}} gradient-dependent intracellular pH shifts in the presence of bicarbonate. The fluorescein derivative BCECF served as a fluorescent probe of intracellular pH in the these experiments. The existence of the Na{sup +}/H{sup +} exchanger was demonstrated in pH{sub i} experiments using BCECF. Further experiments characterized the kinetics of the Na{sup +}/H{sup +} exchanger and its regulation. The steady-state pH{sub i} of ventricular myocytes was 7.16 {+-} 0.11 at pH{sub 0} = 7.4. Several agonists caused a rise in steady-state pH{sub i}: the protein kinase stimulator phorbol myristate acetate (PMA), the {alpha}{sub 1}-adrenergic agonist 6-fluoro-norepinephrine (6F-NE) and the {beta}-agonist UK14304, and ATP.

• Research Organization: Emory Univ., Atlanta, GA (USA)
• OSTI ID: 6622276
• Country of Publication: United States
• Language: English

Related Subjects

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560300 -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACID CARBONATES
ALKALI METAL COMPOUNDS
ANIMALS
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BODY
CARCINOGENS
CARDIOVASCULAR SYSTEM
CHLORIDES
CHLORINE 36
CHLORINE COMPOUNDS
CHLORINE ISOTOPES
DOMESTIC ANIMALS
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ESTERS
FERMIONS
FLUORESCENCE
HADRONS
HALIDES
HALOGEN COMPOUNDS
HEART
ION EXCHANGE
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LUMINESCENCE
MAMMALS
MEMBRANE TRANSPORT
NUCLEI
NUCLEONS
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PH VALUE
PHORBOL ESTERS
PROTONS
RADIOISOTOPES
RUMINANTS
SHEEP
SODIUM COMPOUNDS
TRACER TECHNIQUES
VERTEBRATES
YEARS LIVING RADIOISOTOPES