Histological studies were carried out on the degranulation of mesenteric mast cells of white rats caused by injections of morphine and nalorphine hydrochloride intravenously and the following conclusions were obtained. 1. By the injection of morphine hydrochloride fairly significant degranulation of the mesenteric mast cell was observed. 2. In various experimental doses of morphine hydrochloride the cytological change of the degranulation was not proportional to the doses of it in cases given more than 12mg./kg. of body weight. 3. The degranulating effect of the mesenteric mast cell by the injection of morphine hydrochloride was significantly inhibited by an adrenalectomy.
Adrenalectomy ; Animal ; Male ; Mast Cells/drug effects* ; Mesentery/drug effects* ; Morphine/antagonists & inhibitors ; Morphine/pharmacology* ; Nalorphine/pharmacology ; Rats