Effects of temperature and buffer composition on calcium sequestration by sarcoplasmic reticulum and plasma membrane of rabbit renal artery

Journal Article · Thu Nov 01 00:00:00 EST 1990 · Anatomical Record; (USA)

DOI:https://doi.org/10.1002/ar.1092280308· OSTI ID:5989235

McGuffee, L J; Little, S A; Mercure, J V; Skipper, B J; Wheeler-Clark, E S ^[1]

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1. Univ. of New Mexico, Albuquerque (USA)

45Ca electron microscopic autoradiography was used to examine the effects of buffer composition and temperature on the distribution of calcium in rabbit renal artery smooth muscle cells. The results show that the relative distribution of calcium is dependent on both the buffer used (Tris or Krebs) and the temperature of the bathing solution (25 degrees C or 34{degrees}C). Krebs buffer at 34{degrees}C gave the highest relative activity in the plasma membrane, sarcoplasmic reticulum, and mitochondria. Buffer and temperature had little effect on the relative activity of the nucleus or cytoplasm. Next, we identified the cellular sites of calcium accumulation after 5, 15, 30, or 60 min exposure to {sup 45}Ca in Krebs buffer at 34{degrees}C. The results show that sarcoplasmic reticulum and plasma membrane are the primary sites of calcium accumulation during influx into these cells. Although the amount of {sup 45}Ca in the cell continues to increase with longer exposure, the relative distribution of calcium is essentially the same after 5 or 60 min. The data also indicate that the relative activity of plasma membrane + sarcoplasmic reticulum (a combination site that includes sarcoplasmic reticulum within a mean distance of 275 nm of the plasma membrane) is similar to the membrane alone and is lower than the sarcoplasmic reticulum alone.

• OSTI ID: 5989235
• Journal Information: Anatomical Record; (USA), Vol. 228:3; ISSN 0003-276X
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
BUFFERS
CHEMICAL COMPOSITION
CALCIUM
SUBCELLULAR DISTRIBUTION
ARTERIES
AUTORADIOGRAPHY
CALCIUM 45
CELL MEMBRANES
CELL NUCLEI
CYTOPLASM
KIDNEYS
MEMBRANE TRANSPORT
MITOCHONDRIA
RABBITS
SARCOPLASMIC RETICULUM
TEMPERATURE EFFECTS
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METALS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BLOOD VESSELS
BODY
CALCIUM ISOTOPES
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
DAYS LIVING RADIOISOTOPES
DISTRIBUTION
ELEMENTS
ENDOPLASMIC RETICULUM
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
ISOTOPES
MAMMALS
MEMBRANES
METALS
NUCLEI
ORGANOIDS
ORGANS
RADIOISOTOPES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques