[Effect of gastrin and H2-receptor antagonist on electrical control activity following canine intestinal transection].

Our objective was to study the mechanism of action of gastrin and histamin H2 receptor antagonist on the motility of the gastrointestinal area. In each of 12 mongrel dogs, eight bipolar electromyograms were obtained from the antrum of the stomach to the ileum on serosal surface, and in nine dogs undergoing that the small intestine was transected 20 cm from the ligament of Treitz. The effects of tetragastrin (1.0-10.0 microgram.kg-1.h-1) were studied against the presence of atropine, cimetidine and d-chlorpheniramine maleate. The frequency of electrical control activity (ECA) along the canine small intestine, and changes in ECAs frequency were studied normal and following upper small intestinal transection. In intact, the frequency of ECAs gradient decreased aborally in a stepwise fashion in normal intestine. Although the gradient was markedly reduced or even abolished distal to the level of transection, an intrinsic ECAs frequency gradient was demonstrated, it remained at a low level indefinitely. The normal ECA pattern and its alterations following transection were significantly influenced by tetragastrin. The act of tetragastrin in a dose of 1.0 to 5.0 microgram.kg-1.h-1 had not statistically effect on ECAs frequency and its dysrhythmias, and it did cause a small increase in the frequency of ECA at the antrum, whereas, with the highest dose (10.0 microgram.kg-1.h-1) of used, the increase of mean frequency of ECA in the distal portion to the line of transection, in particular, was significantly greater compared to the change in the proximal portion. It was only cimetidine (8.0 mg.kg-1) that antagonized this action of tetragastin (10.0 microgram.kg-1.h-1). Histamine H2 receptors are suspected of being associated with the action the gastrin has of enhancing ECAs frequency. The results of this study indicate that histamine H2 receptors regularize gastrointestinal ECAs frequency.

[Effects of buprenorphine on gastrointestinal interdigestive myo-electric complex in dogs].

The effect of buprenorphine on the interdigestive myoelectric complex (IMC) was studied by gastrointestinal electromyogram in 3 mature mongrel dogs. The electromyograms were used to study the IMC cycle and total elapsed time (TET). Buprenorphine had very strong hyperkinetic action on the gastrointestinal tract at doses of 1 and 2 micrograms/kg which revealed phasic contraction, but since this action disappeared when atropine was administered. The phasic contraction originated in the upper jejunum just under the ligament of Treitz and then showed a migration pattern of J-->D and J-->I in 11 out of 23 cases (47.8%), D-->J-->I in nine cases (39.1%), J-->D-->J-->I in one case and no response in two cases. TET (min) showed a mean value of 90.3 +/- 11.2 (n = 23), which was not significantly different from the controls (106.1 +/- 14.3) (n = 24), but tended to be longer (0.1 > p > 0.05). After administration of buprenorphine at a dose of 20 micrograms/kg, phasic contraction migrated to ileum, which was disappeared an interval of 6-7 hours until next IMC. At low doses of buprenorphine were administered after a meal, the postprandial pattern was restored and converted to fasted pattern only one IMC cycle. Buprenorphine is partial agonist for the mu receptor. Ahmad et al. (1989) reported that alpha 2 adrenergic receptor and opiate receptors (mainly mu) were presented in submucosal plexus. In concludes that alpha 2 adrenergic activity and other humoral factors seems to take an important role for the initiation of phasic contraction and to control maintenance of IMC cycle.

[Experimental investigations of the propagation mechanism and the nerve regulatory mechanism of the interdigestive migrating electric complex in intestinal movement].

Segments and Thirty-Vella type loops of the small intestine of dogs were prepared, and the excitation propagation pattern of the interdigestive migrating electric complex (IMEC) was observed by electromyography. The nerve regulatory mechanism in intestinal movement was investigated. The results indicated that first, the frequency of the basic electric rhythm (BER) is controlled so that a downward gradient is formed from the upper to the lower intestine, but this gradient continues to be controlled by a two-dimensional control mechanism involving parietal factors and extrinsic nerves due to transection of the intestines and damage to the extrinsic nerves in the dominant region. However, propagation of the IMEC in the small intestine appeared to be regulated by a combination of the two-dimensional control mechanism involving extrinsic and parietal nerves corresponding to the BER control mechanism. It was clear that the propagation mechanism of IMEC is related to the BER frequency, and propagation of the IMEC is downward in accordance with the frequency gradient of BER.

[Early combined carcinoma and malignant lymphoma in the stomach associated with tonsillar malignant lymphoma--report of a case].

This report deals with a histologic demonstration of a combined tumor of early signet ring cell carcinoma and lymphoma of the stomach in a 52-year-old Japanese man. The Gastric carcinoma was found by a systemic work up for a tonsillar lymphoma. The relationship between the malignant lymphomas of the stomach and of the tonsil is not clear in this case. The carcinoma and lymphoma of the stomach were both small, and the depth of invasion was localized to the mucosa and submucosa, respectively. The lymphoma was observed just beneath the cancer and was a diffuse, large cell type, and of the same histologic typing as the tonsillar lymphoma. Based on the broader size of the carcinoma, it is considered that the carcinoma probably induced the lymphoma in the stomach. This of an early combined tumor of carcinoma and lymphoma of the stomach is, to our knowledge, the first to be reported in the literature.

[Gastric carcinoma with prominent reactive lymphoid hyperplasia; report of two cases with an immunohistological study].

An immunohistological study using a Leu 7 antibody, which is a marker for human NK and K cells, was carried out in two cases of gastric carcinomas with prominent reactive hyperplasia. The patients were a 72-year-old man and a 55-year-old man who had shown good postoperative courses in spite of the advanced stage of their tumors. There were many scattered Leu 7 positive cells in the lymphoid hyperplasia, predominantly in the germinal centers and the peri-follicles. The number of Leu 7 positive cells were even more pronounced in a patient whose condition was more advanced. These findings suggest that lymphoid hyperplasia, particularly with regard to the NK and K cell response, plays a significant role in the clinical benignity of the tumors.