The influence of harvesting intervals on chemiluminescence and enzyme activities of rat peritoneal leukocytes.

Rat leukocytes were obtained from the peritoneal cavity by stimulation with potassium caseinate. The chemiluminescence response of the polymorphonuclear leukocytes exposed to opsonized zymosan was influenced by the interval between instillation of caseinate and harvesting of the cells. With intervals increasing from four to 72 hours, the maximum activity was reached after 24 hours. The myeloperoxidase activity of all the leukocytes together increased gradually up to 72 hours after instillation of caseinate. After exposure to zymosan particles, only a negligible fraction of this enzyme was released from the cells. On the other hand, the lysozyme activity was highest in cells harvested early, and a large fraction of this enzyme was also released from these cells. The findings emphasize the importance of standardized conditions for stimulation and harvesting of rat peritoneal leukocytes.