It is well known that the mast cells, containing metachromatic granules, occur in almost all structures in body, especially in loose or areolar connective tissues. The granules in mast cell contain heparin, histamine, hyaluronic acid, serotonin, other mucopolysaccharides and certain enzymes or their precusors, but they are readily diffused from the cells by various physical and chemical stimuli. Based on the above mentioned, this study was carried out to demonstrate the degranulation and disruption of mesenteric mast cells in mice by means of dactinomycin administration.
The animals used in this experiment were well developed mature albino mice, ICR strain, weighing approximately 20 gm. Dactinomycin was injected through intramuscalar route in an amount of 0.25mg per kg. and the animals were killed at 6, 12 and 24 hours after administration. Absolute methanol was directly infused into peritoneal cavity through a small incision of the anterior median abdominal wall of the mice and then fixed 20 minutes in situ in order to reduce the direct mechanical injury to mesenteric mast cell. A few pieces of mesentery were carefully excised and stained with Pugh´s solution containing toluidine blue. The degree of degranulation of mesenteric mast cells were divided into 4 grades; normal mast cells, slight degranulation, moderate degranulation and severe degranulation or disruption. All specimens were observed with light microscope.
The results were as follows:
1. The total number of mesenteric mast cells were reduced in dactinomycin treated mice.
2. Percentage of degranulated mesenteric mast cells was increased in dactinomycin treated mice.
Consequently, it is suggested that dactinomycin should degranulate mesenteric mast cells.
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