Studies in Experimental Eosinophilia

Abstract

Summary The draining lymph nodes of guinea pigs were examined histologically after the injection of BSA or hemocyanin into footpads. When a 10-mg dose of hemocyanin was administered, increased numbers of eosinophils were detected as early as 4 hr, and the peak response was seen at 12 hr. Margination, diapedesis and perivascular cuffing by eosinophils were prominent features in lymph nodes removed during the 1st hr, and such changes were evident as early as 5 min after the first exposure to hemocyanin. Similar findings were obtained with BSA, but the earliest changes were noted at 1 hr. When BSA, labeled with fluorescein, was injected into footpads, green fluorescence was noted in the draining lymph node as early as 5 sec. The experiments are consistent with the view that de novo synthesis of antibody may occur within 5 min of the first encounter of an organism with an antigen.