Inadequate cytoplasmatic calcium signals in alveolar macrophages after cardiac surgery.
OBJECTIVE
Patients undergoing cardiac surgery have an elevated risk for pulmonary complications. A dysfunction of alveolar macrophages (AM) might promote postoperative infections. Therefore intracellular calcium [Ca(2+)](i) as an important second messenger in cellular signaling was assessed in AM.


METHODS
Twelve patients undergoing elective coronary artery bypass graft surgery (CABG) were enrolled in this clinical trial. After anesthesia induction and 2 h after cardiopulomary bypass (CPB) declamping, the bronchoalveolar lavage (BAL) fluid was collected preoperatively from the right middle lobe and postoperatively from the left lingula of the lung. Cell subpopulations and [Ca(2+)](i) signals were assessed via flow cytometry. To express the changes of [Ca(2+)](i) signals the Fluo4/FuraRed-Ratio was used.


RESULTS
After surgery the [Ca(2+)](i) baseline in unstimulated AMs were significantly reduced (p < 0.001). A significant signal reduction after fMLP (p = 0.021) and C5a (p = 0.028) stimulation was found in FSC high AMs after surgery, even though all populations showed a trend of less responsiveness.


CONCLUSIONS
We suggest that the reduced [Ca(2+)](i) signaling in postoperative AMs is caused by a reduced coupling to membrane channels. These preliminary data suggest an inadequate [Ca(2+)](i) signal of AM after surgery, which may contribute to a local immune dysfunction in the lung.
Berger
Katharina
K
Department of Anesthesiology and Intensive Care Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany.
Sander
Michael
M
Kohlar
Anke
A
Meisel
Christian
C
Konertz
Wolfgang
W
Volk
Thomas
T
D000368:Aged; D001992:Bronchoalveolar Lavage Fluid; D002118:Calcium / Q000032:analysis; D020013:Calcium Signaling; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D003593:Cytoplasm / Q000378:metabolism*; D005260:Female; D006801:Humans; D008168:Lung / Q000276:immunology; D016676:Macrophages, Alveolar / Q000276:immunology*; D008297:Male; D018410:Pneumonia, Bacterial / Q000209:etiology*; D011183:Postoperative Complications / Q000382:microbiology*
D002118:Calcium