Blood components contribute to rise in gerbil brain levels of leukotriene-like immunoreactivity after ischemia and reperfusion.

The mean +/- SEM concentrations of immunoreactive leukotriene C4 and D4 (iLTD4) and prostaglandin D2 (iPGD2) increased from 3.0 +/- 1.2 and 0.71 +/- 0.33 to 16.3 +/- 4.7 and 3.0 +/- 1.14 ng/g forebrain, respectively (p less than 0.05, iLTD4; p less than 0.01, iPGD2), in the forebrains of 12 gerbils after 15 minutes of bilateral common carotid artery occlusion and 15 minutes of reperfusion. Removal of blood from ischemic brain of 11 gerbils by intracardiac perfusion with ice-cold saline for 10 minutes decreased iLTD4 concentrations significantly to 7.0 +/- 0.9 (p less than 0.05) but did not change iPGD2 concentrations. Severe granulocytopenia (4.98 +/- 1.79 to 0.05 +/- 0.03 x 10(3)/mm3, p less than 0.01) in seven gerbils following intraperitoneal injection of 50 mg/kg busulfan was associated with decreased iLTD4 accumulation in the brain to 3.46 +/- 1.36 ng/g forebrain (p less than 0.01). Taken together, our results suggest that blood components (most likely leukocytes) are a source of leukotriene-like immunoreactivity in the ischemic and reperfused brain.