Production of eosinophil-rich guinea pig peritoneal exudates

A variety of methods for production of eosinophil-rich guinea pig peritoneal exudates were tested in order to procure large numbers of purified eosinophils. Repeated peritoneal lavage with saline did not produce peritoneal eosinophilia, nor did intraperitoneal injection of dextran beads. Mast cell degranulating agents polymyxin B and, to a lesser degree, compound 48/80 produced significant peritoneal eosinophilia after 6-8 wk of weekly intraperitoneal injections (p = 0.05). After more than 8 wk of treatment a mean of 52.1 x 10⁶ eosinophils comprising an average of 62% of the peritoneal exudate cells was recovered from polymyxin B-treated guinea pigs. However, polymyxin B-induced peritoneal eosinophilia was abolished by pretreatment with the antihistamine diphenhydramine. Metiamide, an H₂ receptor antagonist, did not block the production of peritoneal eosinophils. This is a highly satisfactory method for preparing peritoneal eosinophils; however, the mechanism of action remains to be clearly elucidated.