Expression of cardiac sarcolemmal Na sup + -Ca sup 2+ exchange activity in Xenopus laevis oocytes
- Univ. of California, Los Angeles (USA)
Injection of Xenopus laevis oocytes with rabbit heart poly(A){sup +}RNA results in expression of Na{sup +} inside (Na{sub i}{sup +})-dependent Ca{sup 2+} uptake activity. The activity was measured by first loading the oocytes with Na{sup +} using nystatin and then incubating the oocytes in K{sup +} or Na{sup +} medium containing {sup 45}Ca. The expressed Na{sup +} gradient-dependent Ca{sup 2+} uptake was five to eight times that observed with water-injected oocytes or with poly(A){sup +}RNA-injected oocytes for which the Na{sup +} load step had been omitted. Induced activity was related to the amount of RNA injected and was insensitive to nifedipine. Fractionation of the poly(A){sup +}RNA on a sucrose gradient determined that the active message had a size range between 3 and 8 kb. The properties of the Na{sup +} gradient-dependent Ca{sup 2+} uptake indicated that Na{sup +}-Ca{sup 2+} exchange activity had been expressed in X. laevis oocytes. The result may be useful for cloning and identifying the molecular component responsible for Na{sup +}-Ca{sup 2+} exchange.
- OSTI ID:
- 6252550
- Journal Information:
- American Journal of Physiology; (USA), Vol. 255:6; ISSN 0002-9513
- Country of Publication:
- United States
- Language:
- English
Similar Records
Expression of mammalian beta-adrenergic receptors in Xenopus laevis oocytes
mRNA-induced expression of the cardiac Na/sup +/-Ca/sup 2 +/ exchanger in Xenopus oocytes
Related Subjects
CALCIUM 45
UPTAKE
MEMBRANE TRANSPORT
MOLECULAR BIOLOGY
SODIUM 22
CELL MEMBRANES
CENTRIFUGATION
HEART
MESSENGER-RNA
OOCYTES
SCINTILLATION COUNTING
TOADS
ALKALI METAL ISOTOPES
ALKALINE EARTH ISOTOPES
AMPHIBIANS
ANIMALS
AQUATIC ORGANISMS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CALCIUM ISOTOPES
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
EVEN-ODD NUCLEI
GERM CELLS
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIGHT NUCLEI
MEMBRANES
NUCLEI
NUCLEIC ACIDS
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
RADIOISOTOPES
RNA
SEPARATION PROCESSES
SODIUM ISOTOPES
VERTEBRATES
YEARS LIVING RADIOISOTOPES
551001* - Physiological Systems- Tracer Techniques