[Gastric emptying in patients with gastroduodenal disease. First report: peptic ulcer and its recurrence (author's transl)]

Immunocytochemical Detection of Synaptophysin in Enteric Neurones during Prenatal Development in the Rat Stomach

Summary In this study, the localization and appearance of synaptophysin-immunoreactive (IR) nerve cells and their relationships with the developing gastric layers were studied by immunocytochemistry and light microscopy in the embryonic rat stomach. The stomachs of Wistar rat embryos aged 13-21 days were used. The first neuronal bodies and their processes containing synaptophysin-immunoreactivity were observed on embryonic day 13. In contrast, synaptophysin-IR nerve terminals were first observed between mesenchymal cells on embryonic day 14. These results indicate that synaptophysin is expressed in growing neurits and neuronal cell bodies before these neurones have established synaptic connections. The occurrences of mesenchymal cell condensation near synaptophysin-IR neuroblasts on embryonic day 15 reflect an active nerve element-specific mesenchymal cell induction resulting in the morphogenesis of muscle cells. Similarly, the appearance of glandular structures after synaptophysin-IR neuroblasts, on embryonic day 18, suggests that the epithelial differentiation may be closely related to the neuronal maturation as well as other factors. Finally, synaptophysin is functionally important in neuronal development and maturation, together with the establishment of neuroneuronal and neuromuscular contacts and in epithelial differentiation.

Immunocytochemical detection of neuronal nitric oxide synthase (nNOS)-IR in embryonic rat stomach between days 13 and 21 of gestation

In this study, the localization and appearance of neuronal nitric oxide synthase-immunoreactive (nNOS-IR) nerve cells and their relationships with the developing gastric layers were studied by immunocytochemistry techniques and light microscopy in embryonic rat stomach. The stomachs of Wistar rat embryos aged 13-21 days were used. The first nerve cells containing nNOS-IR were seen on embryonic Day 14. The occurrence of mesenchymal cell condensation near nNOS-IR neuroblasts on embryonic Day 15 may reflect an active nerve element-specific mesenchymal cell induction causing the morphogenesis of muscle cells. Similarly, the appearance of glandular structures after nNOS-IR neuroblasts, on embryonic Day 18, suggests that the epithelial differentiation may depend on inputs coming from nNOS-IR neuroblasts, as well as other factors. Observation of nNOS-IR nerve fibers on embryonic Day 21 demonstrates that at this stage they contribute to nonadrenergic noncholinergic relaxation. In conclusion, depending on this study's results, it can be said that cells and tissues might be affected by NO secreted by nNOS-IR nerve cells during the development and differentiation of embryonic rat stomach.

Gastric emptying in deformed stomach

To evaluate the relationship between the onset of peptic ulcer and gastric emptying, some factors which were thought to regulate gastric emptying, i.e. the stage of the ulcer, the location of the ulcer and gastric acidity were studied in cases of gastric ulcer with deformed stomach and were proven to have little influence on gastric emptying. Further, the main cause of delayed gastric emptying was revealed to be the deformity itself, because the shortening of the distance from the gastric angle to the pyloric ring at the lesser curvature (sac-shaped stomach) and the indentation of the corpus ventriculi (hourglass-shaped stomach) significantly delayed gastric emptying. Moreover, it was found that the healing of gastric ulcer was delayed in cases of deformed stomach with delayed gastric emptying when the ulcer was at an active stage. Therefore the improvement of gastric emptying by some methods was thought to be necessary to promote ulcer healing and prevent ulcer recurrence in gastric ulcer patients who had a deformed stomach.

Effects of pentagastrin, histamine, carbamylcholine and catecholamines on gastric secretion, motility and emptying in the rat

We developed a simplified method for the simultaneous measurement of gastric secretion and gastric motility in the rat. By using this method, we investigated the actions of pentagastrin, histamine, carbamylcholine and catecholamines on the stomach. Carbamylcholine stimulated acid secretion and induced contraction of the stomach, but norepinephrine tended to inhibit acid secretion and induced relaxation of the stomach. Histamine induced relaxation first and then contraction after 2-5 min. Pentagastrin induced a relaxation that did not show dose dependence, but tachyphylaxis. Isoproterenol, which stimulated acid secretion in our experiments, induced relaxation of the stomach in a dose-dependent manner. We also investigated the relationship between gastric motility and gastric emptying. Carbamylcholine caused an enhancement of gastric emptying, but isoproterenol caused its suppression. Pentagastrin, histamine and norepinephrine did not affect gastric emptying. As shown in the results of our experiments, carbamylcholine caused stimulation of acid secretion, contraction of the stomach, and enhancement of gastric emptying. However, other secretagogues did not always induce contraction of the stomach or increase gastric emptying.