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Lung

, Volume 180, Issue 4, pp 215–220 | Cite as

Lipopolysaccharide (LPS) Enhancement of Outward Current in Lung Pericytes

  • J.J. Herskovic
  • C.L. Speyer
  • J.E. Simples
  • C.P. Steffes
  • J.L. Ram

Patch clamp methods were used to study the effect of lipopolysaccharide (LPS), an endotoxin produced by gram-negative bacteria, on voltage-dependent outward current of lung pericytes. Pericytes are located in capillary walls and may mediate pathological changes in microvascular hemodynamics and permeability that accompany endotoxin-mediated pulmonary edema. Previous studies have shown that LPS reduces lung pericyte contractility. Lung pericytes exhibited a voltage-dependent outward current, presumed to be K+ current, and this current increased in magnitude in response to LPS. Cells incubated for 48 hr without LPS (control) had an average peak current at 50 mV of 101 pA (n = 5 cells), whereas cells incubated with 100 mg/ml LPS had an average peak current of 927 pA (n = 9 cells, P<0.01 compared to control). When held at 50 mV for 50 msec, net outward current decreased in control cells by 10.7% and in LPS-treated cells by 2.6% (P<0.05). The increased activation of outward current in LPS-treated cells may be due to a previously inactive potassium channel and may mediate LPS-induced relaxation of the lung pericyte.

Keywords

Potassium Control Cell Pathological Change Pulmonary Edema Potassium Channel 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag New York Inc. 2002

Authors and Affiliations

  • J.J. Herskovic
    • 1
  • C.L. Speyer
    • 2
  • J.E. Simples
    • 3
  • C.P. Steffes
    • 2
  • J.L. Ram
    • 1
  1. 1.Department of Physiology, Wayne State University, Detroit, MI, 48201, USAUS
  2. 2.Department of Surgery, Wayne State University, Detroit, MI, 48201, USAUS
  3. 3.Research Department, VA Medical Center, Detroit, MI 48201, USAUS

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