| Co-Investigator(Kenkyū-buntansha) |
ADACHI Naoto EHIME UNIVERSITY,MEDICINE,ASSISTANT, 医学部・附属病院, 助手 (50253315)
MOCHIZUKI Takatoshi EHIME UNIVERSITY,MEDICINE,ASSISTANT, 医学部, 助手 (40263933)
GOTOH Yoshinori EHIME UNIVERSITY,MEDICINE,LECTURER, 医学部, 講師 (10162166)
YAMATODANI Atsushi OSAKA UNIVERSITY,MEDICINE,PROFESSOR, 医学部, 教授 (30116123)
WATANABE Takehiko TOHOKU UNIVERSITY,MEDICINE,PROFESSOR, 医学部, 教授 (70028356)
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| Research Abstract |
In this research project, using mast cell deficient (Ws/Ws) rats, roles of histamine in the pathophysiological conditions such as allergy, gastric ulcer and behavior have been investigated. There are at least two types of histamine pools : one is mast cell-histamine and another is nin-mast cell histamine. As mast cells contain high amount of histamine and are distributed widely, it was difficult to differentiate these two histamine pools. Ws/Ws rats, which has a mutation of c-kit receptor, completely deplete connective tissue type of mast cells. Therefore, histamine contents in tissues of Ws/Ws rats derive from non-mast cell histamine. We can clearly demonstrate the existence of non-mast cell histamine and its roles as follows.
1.Histamine content in the brain of Ws/Ws rats is 63% of the congenic (+/+) rats and it decreased to 37% of the control level after treatment of alpha-fluoromethylhistidine, a suicide inhibitor of histidine decarboxylase. The remaining content of histamine might
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be due to other pool than mast cells and neuron. (J.Neurochem.65 : 791,1995)
2.Using in vivo microdialysis technique, the relationship between edema formation and histamine release in the paw was studied. After treatment of compound 48/80, histamine release sharply occurs in 20 min and decreased gradually through 3 hrs in +/+ rats but no edema formation and histamine release was observed in Ws/Ws rats. Compound 48/80 stimulates histamine release from mast cells and edema formation. (Eur.J.Pharmacol.331 : 237,1997)
3.In water immesion stress, plasma histamine levels increased biphasically in normal rats. In the first phase, it reached a peak at 15 min and the second increase was observed between 1.5-6 hrs. After gastrectomy, the second increasein plasma histamine disappeared. In Ws/Ws rats, the water immersion stress causes no first peak and aftr gastrectomy, both increases in plasma histamine disappeared. Non-immunological stimulant causes histamine release from mast cells after water immersion stress. Less
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