Plasmolemmal potassium gradient does not affect lung protection by an ATP-regulated potassium channel opener.

Abstract

BACKGROUND:

We have previously shown that metabolic arrest induced with ATP-regulated potassium channel openers (PCOs) can improve lung preservation by adding Aprikalim (a PCO, Rhone-Poulene Roher) to modified Euro-Collins solution for pulmonary artery flush. Because the membrane hyperpolarizing effects of a PCO potentially competes with the depolarizing effects of a hyperkalemic solution, this study evaluated the effects of the potassium gradient on PCO-mediated lung protection.

STUDY DESIGN:

Twenty rabbits underwent lung protection in four groups. Group 1 underwent harvest and reperfusion as a "no ischemia" control. Groups 2, 3, and 4 underwent harvest followed by 18 hours of cold ischemic storage before reperfusion. Groups 1 and 4 received Euro Collins as the pulmonary flush at induction of ischemia. Group 2 received Euro Collins plus Aprikalim (100 microM); and group 3 received lactated Ringer's plus Aprikalim. After ischemic storage, the lungs were reperfused with autologous blood for 2 hours. Every 30 minutes, the lungs were given a 10-minute 100% fractional inspired oxygen (F(i)O(2)) challenge to measure maximal gas exchange as an indication of graft function.

RESULTS:

Repeated measures ANOVA showed Aprikalim improved graft function after 18 hours of cold ischemia (p < 0.0001). No significant differences were found when Aprikalim was used in either Euro-Collins (group 2) or lactated Ringer's (group 3) solution.

CONCLUSIONS:

The ability of the PCO Aprikalim to preserve gas exchange in a model of hypothermic pulmonary ischemia-reperfusion injury was not affected by the plasmolemmal potassium gradient. This is consistent with recent findings in myocardial protection studies that the protective effects of PCOs may be intracellular.

• Authors: Daniel G Tang, Alexandru M Vaida, Robert Wise, Robert S D Higgins, Neri M Cohen
• Journal: Journal of the American College of Surgeons (J Am Coll Surg) Vol. 198 Issue 6 Pg. 960-5 (Jun 2004) ISSN: 1072-7515 [Print] United States
• PMID: 15194079 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Euro-Collins' solution
• Hypertonic Solutions
• Isotonic Solutions
• Organ Preservation Solutions
• Picolines
• Potassium Channels
• Pyrans
• Ringer's Lactate
• aprikalim
• Adenosine Triphosphate

Topics

• Adenosine Triphosphate (physiology)
• Animals
• Female
• Hypertonic Solutions (pharmacology)
• Isotonic Solutions (pharmacology)
• Lung (blood supply)
• Lung Transplantation
• Male
• Organ Preservation Solutions (chemistry, pharmacology)
• Picolines (pharmacology)
• Potassium Channels (drug effects)
• Pulmonary Gas Exchange
• Pyrans (pharmacology)
• Rabbits
• Reperfusion Injury (prevention & control)
• Ringer's Lactate