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Pus potassium
1Department of Research and Internal Medicine, University Hospital, Basel, Switzerland.
Abstract:
Membrane depolarization is an early event in cell stimulation. Since the resting membrane potential is dependent on the potassium composition of the extracellular medium, we investigated whether there are clinical situations in which potassium levels are high enough to depolarize polymorphonuclear leukocytes. We determined the ionic composition of sterile and infected interstitial fluid in humans and guinea pigs. All sterile extravascular fluids had physiological potassium levels in the same range as serum values. In contrast, human abscess fluids contained increased K+-levels (17 +/- 6.4 mmol/liter, N = 8) and 15 of 20 experimental abscesses in guinea pigs contained greater than 10 mmol/liter K+. In humans three of eight abscess fluid K+ levels and in guinea pigs three of five abscess fluid K+ levels were even greater than 15 mmol/liter. Thus, high K+ levels, previously shown to activate polymorphonuclear leukocytes, are observed in certain clinical situations associated with local inflammation.
Insights
High potassium levels in human and guinea pig abscess fluids can depolarize polymorphonuclear leukocytes, suggesting a role for elevated extracellular potassium in inflammatory responses.
Area of Science:
- Cellular physiology
- Immunology
- Biochemistry
Background:
- Resting membrane potential in cells is influenced by extracellular potassium concentration.
- Polymorphonuclear leukocytes (PMNs) are critical immune cells involved in inflammation.
- Membrane depolarization is an initial step in cell activation.
Purpose of the Study:
- To investigate if clinical conditions feature elevated extracellular potassium levels.
- To determine if these high potassium levels can depolarize polymorphonuclear leukocytes.
Main Methods:
- Analysis of ionic composition in sterile and infected interstitial fluid from humans and guinea pigs.
- Measurement of potassium (K+) levels in human and guinea pig abscess fluids.
- Comparison of K+ levels in abscess fluids with physiological ranges.
Main Results:
- Sterile extravascular fluids showed physiological potassium levels, similar to serum.
- Human abscess fluids exhibited elevated K+ levels (17 +/- 6.4 mmol/liter).
- A significant proportion of experimental abscesses in guinea pigs also showed high K+ levels (>10 mmol/liter and >15 mmol/liter).
Conclusions:
- Elevated extracellular potassium concentrations are present in clinical situations associated with local inflammation, such as abscesses.
- These high K+ levels have the potential to depolarize polymorphonuclear leukocytes.
- This finding suggests a mechanism linking inflammation and immune cell activation via potassium ion dynamics.