Tumor necrosis factor and cardiac function

J E DeMeules1, F A Pigula, M Mueller

  • 1Department of Surgery, University of Vermont College of Medicine, Burlington.

Insights

Tumor necrosis factor (TNF) initially enhances heart muscle function. However, this effect is followed by impaired myocardial performance 18-22 hours later, transferable via serum.

Area of Science:

  • Cardiology
  • Immunology
  • Physiology

Background:

  • Tumor necrosis factor (TNF) is a cytokine produced by activated macrophages.
  • The impact of TNF on myocardial performance requires further investigation.

Purpose of the Study:

  • To determine the direct effects of TNF on myocardial performance.
  • To investigate the time-dependent changes in cardiac function following TNF administration.

Main Methods:

  • Isolated papillary muscle technique in rats.
  • Modified Langendorff preparation for whole-heart perfusion.
  • Administration of varying doses of TNF and saline as control.

Main Results:

  • High-dose TNF (100 µg/kg) significantly increased peak tension and contraction velocity.
  • Both TNF doses decreased resting membrane potential.
  • Serum from TNF-treated animals impaired contractility, systolic pressure development, and relaxation 18-22 hours post-treatment.

Conclusions:

  • TNF exerts an early beneficial effect on myocardial function.
  • A later impairment of myocardial performance is observed, suggesting a time-dependent biphasic effect.
  • The later detrimental effect is transferable via serum.

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