[Studies on predilection area of gastric ulcer viewed from gastric motility (author's transl)].

Clinically, most gastric ulcers are located in the region of the incisura angularis, but they are least found along the greater curvature. To elucidate this difference, following experiments were carried out. A total of 22 mongrel dogs were used. A set of bipolar electrodes and/or a water-proof strain gage were chronically implanted at both the incisura and the corresponding site of the greater curvature. Electrical and contractile activities of these two sites were compared at the fasted state and under the stimulations by food, neostigmine and tetragastrin. Results are summarized as follows. 1. Electromyographically, the propagation velocity was always greater along the greater curvature than the lesser curvature. The discharge interval of BER and incidence of antiperistalsis were identical for both the lesser and greater curvature. 2. Through the course before and after the stimulation, there was no difference in the frequency of contraction waves, while the amplitude and motility index of the contraction were definitely greater at the incisura than the corresponding greater curvature. In conclusion, the present study revealed that the contractile force of the incisura was always greater than that of the corresponding greater curvature. It is possible that the peristaltic contraction could cause stronger repetitive ischemic condition of the incisura than the corresponding greater curvature. It is estimated that the gastric motility is one of the important factors for the predilection or delayed healing of gastric ulcers seen in the region of the incisura angularis.