Gastrointestinal histamine after gastric irradiation in the mouse.

A single dose of 9 or 15 Gy of X-rays was given to the stomach of mice. Gastric histamine formation capacity (HFC) rose in a dose-related fashion during days 4 to 11 after irradiation. This rise coincided with a dose-dependent fall in gastric mural histamine concentration. 15 Gy X-rays also resulted in a transient loss of body weight (days 4-8 after irradiation). These results suggest that irradiation of the stomach mobilizes gastric histamine and that gastric histamine stores may be radiosensitive.