| Popis: |
In order to elucidate the role of histamine in early phase of acute inflammation, croton oil induced rat pleurisy and in vitro effect of croton oil on mixed pleural cells were examined. Mixed pleural cells were recovered from male SD-rats by lavage with 5.0 ml HEPES-Tyrode and incubated with croton oil, and released histamine was determined by the method of Shore. Croton oil induced dose-dependent histamine release between 0.0 01 % and 0.1 %. Experimental pleurisy was induced by intrapleural injection of 0.1 ml of 1 % croton oil suspension into male SD-rats (7-8 wks old) and exsanguinated at 1, 3 and 16 hr after injection. The volume of pleural exudate, the rate of exudation, the number of migrated leukocytes and their classification were examined. Pleural cavity was washed with 3.0 ml HEPES-Tyrode and histamine content in the supernatant (s) and cell pellet (p) were determined by above method. Histamine content in (s) was the highest at 1 hr and decreased with time. Histamine content in (p) decreased with time. By pretreatment with mepyramine(5 mg/Kg, i.p.,30 min before), pleural fluid accumulation at 1 hr and exudation rate at 1 hr were significantly suppressed. These results suggest that histamine may play a role in early phase of croton oil induced rat pleurisy. |
