Reduction in the Ca2(+)-induced Ca2+ release from canine cardiac sarcoplasmic reticulum following endotoxin administration.

Abstract

Effects of endotoxin administration on the Ca2(+)-induced Ca2+ release from canine cardiac sarcoplasmic reticulum (SR) were studied. Results show that the Ca2(+)-induced Ca2+ release from either passively or actively loaded SR vesicles was decreased by 28 to 46% (p less than 0.05) 4 h after endotoxin administration. Kinetic analysis reveals that the Vmax for Ca2+ was decreased significantly without changing the S0.5 and the Hill coefficient values. The binding of [3H]ryanodine to cardiac SR was reduced by 25.3% (p less than 0.01) following endotoxin administration. These data demonstrate that the Ca2(+)-induced Ca2+ release via the ryanodine-sensitive Ca2+ channel in canine cardiac SR was reduced during endotoxin shock. A reduction in the SR Ca2(+)-induced Ca2+ release may have a pathophysiological significance in contributing to the development of myocardial depression during endotoxin shock.

• Authors: M S Liu, L L Wu
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 174 Issue 3 Pg. 1248-54 (Feb 14 1991) ISSN: 0006-291X [Print] United States
• PMID: 1996988 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Endotoxins
• Lipopolysaccharides
• Calcium

Topics

• Animals
• Calcium (metabolism, pharmacology)
• Dogs
• Endotoxins (pharmacology)
• Escherichia coli
• Kinetics
• Lipopolysaccharides (pharmacology)
• Male
• Myocardium (metabolism)
• Reference Values
• Sarcoplasmic Reticulum (drug effects, metabolism)
• Shock, Septic (metabolism)