Molecular and Cellular Biochemistry

, Volume 121, Issue 2, pp 143–148

Altered membrane fluidity in rat hepatocytes during endotoxic shock

  • Ravi Salgia
  • John H. Becker
  • Mohammed M. Sayeed
Article

DOI: 10.1007/BF00925973

Cite this article as:
Salgia, R., Becker, J.H. & Sayeed, M.M. Mol Cell Biochem (1993) 121: 143. doi:10.1007/BF00925973

Abstract

Steady-state fluorescence anisotropy measurements of the fluorescent hydrocarbon probe 1,6-diphenyl-1,3,4-hexatriene (DPH) were carried out in isolated hepatocytes of saline control andSalmonella enteritidis endotoxin (20 mg/kg) injected rats. Statistically significant differences were observed in the fluorescent anisotropy (rs) and membrane microviscosity (\(\hat \eta \)) values of control (rs=0.107±0.004 (SEM),\(\hat \eta \)=0.98±0.08, n±6) versus endotoxin injected rat hepatocytes (rs=0.134±0.005,\(\hat \eta \)=1.43±0.08, n=6, p<0.001) at 37°C. Fluidity was similarly lower in the isolated plasma membrane preparations from endotoxin-injected rat livers relative to control livers. When endotoxin-injected rats were treated with the calcium channel-blocker diltiazem, the anisotropy and microviscosity values were comparable to thos eobtained from control rats (rs=0.152±0.003,\(\hat \eta \) =1.00±0.003, n=6). These measurements were made in animals five hours after endotoxin had been injected, and thus represent thein vivo effects of bacterial endotoxins. Temperature scan studies of DPH from 5–40°C revealed that the membrane fluidity of endotoxin-injected rat hepatocytes was significantly lower than control hepatocytes at all temperatures investigated. The data suggest that endotoxin alters the membrane fluidity of hepatocytes, and that calcium-channel blockers can prevent the alteration. Our previous studies have shown that calcium channel blocker prevented endotoxin induced alterations in hepatic cellular regulation of Ca2+. Thus, cellular calcium homeostasis may be important in the maintenance of membrane fluidity and other membrane-associated transport functions. (Mol Cell Biochem121: 143–148, 1993)

Key words

endotoxinmembrane microviscosityliver cellshepatic plasma membranediltiazem

Copyright information

© Kluwer Academic Publishers 1993

Authors and Affiliations

  • Ravi Salgia
    • 1
  • John H. Becker
    • 2
  • Mohammed M. Sayeed
    • 3
  1. 1.Dept. of MedicineJohns Hopkins Univ. School of MedicineBaltimore
  2. 2.Dept. of Physiological SciencesWm. M. School College of Podiatric MedicineChicago
  3. 3.Department of PhysiologyLoyola University Stritch School of MedicineMaywoodUSA