There tissue mast cells, which were first described in 1877 by Ehrlich, contain metachromatic granules in the cytoplasm. They store heparine, histamine, serotonine and hyalruronic acid and distribute in surrounding connective tissues.
Smith(1958) and Riley(1953a) found the liberation of histamine is accompanied by disruption and degranulation of the mast cells. Laugnoff and Benditt(1960) and Riley and West(1953) reported that the liberation was induced by several factors: mechanical stimuli, injection of tissue extracts, administration of histamine liberators. Goldgraber and Lowert(1965) and Wells(1962) induced the liberation of histamine by the infestation of parastites and an injection of the extracts of parasitos. Fernex, M. and Fermex, P.(1962) experienced that the infections of Schistosoma mansoni, Hymenolepsis nana and Syphacia induced the increase of mast cell number in the skin of the infected white mice.
Blood eosinophilia is commonly observed in helminthic infections and also is found either by injection of parasite extracts or histamine (Campbell 1942, Vaughn 1953).
The present study was designed to investigate the relationship between tissue mastocytosis and blood eosinophilia in white mice infected with Entamoeba histolytica.
Parasite free 49 mice were used for 3 experimental groups control 16, sham operation 16, infection 17. The last experimental group was infected directly to cecum by laparotomy with 5000 Entamoeba histolytica tropozoits, with were originated from the hepatic amoebic absoess. Two, 9, 18 and 34 days after the infection, blood eosinophils were checked by Wright's stain. At the same time all animals were sacrificed for mast cell examination. Samples of mesenterie pieces from the region of terminal iloum were fixed in 100% methyl alcohol and stained
with Pugh's solution containing toluidino blue, which was used by Leblane and Resenberg(1957).
The mast cells in twenty microscopic fields of the mesentery were observed and counted. The ulcers in ceca were also examined by the histological method.
As a result, the changes of mesenteric mast cells and blood eosinophils of mice infected with Entamoeba histolytica were as follows.
1. The number of mast cell in mesenteric tissues of the infected group increased from 9th day of infection and the increased number persisted up to 34th day, the last date of this experiment.
2. The disruption and degranulation of mast cells increased in the infected group compared with groups of the sham operation and the control.
3. The blood eosinophilia was observed from 9th day of the infection and persisted until the 34th day, the last date of this experiment.
4. Ulcers in cecum were found in 3 out of 4 infected mice from 9th day.