Postprandial Gastrointestinal Hormone Production Is Different, Depending on the Type of Reconstruction Following Total Gastrectomy

OBJECTIVES: The present study examines the differences in gastrointestinal hormone production at 3 different reconstruction types after total gastrectomy. BACKGROUND DATA: Total gastrectomy causes significant weight loss, mainly due to a reduced caloric intake probably because of a lack of initiative to eat or early satiety during meals. Behind this phenomenon a disturbed gastrointestinal hormone production can be presumed. METHODS: Patients participating in a randomized study were recruited for the clinical experiment. Seven patients with simple Roux-en-Y reconstruction, 11 with aboral pouch (AP) construction, and 10 with aboral pouch with preserved duodenal passage (APwPDP) reconstruction, as well as 6 healthy volunteers were examined. Blood samples were taken 5 minutes before and 15, 30, and 60 minutes after ingestion of a liquid test meal. Plasma concentrations for insulin, cholecystokinin, and somatostatin were determined by radioimmunoassay analysis. RESULTS: Postprandial hyperglycemia was observed in patients after total gastrectomy most prominently in groups with duodenal exclusion (Roux-en-Y and AP) compared with healthy controls. Postprandial insulin curves reached significantly higher levels in all operated groups compared with controls, however, with no difference according to reconstruction type. Significantly higher cholecystokinin levels and higher integrated production of cholecystokinin were observed in Roux-en-Y and AP groups compared with APwPDP and control. Postprandial somatostatin levels were significantly different between the 4 groups, and highest levels and integrated secretions were reached in AP group, lowest in APwPDP and normal groups. CONCLUSION: A disturbed glucose homeostasis was observed in gastrectomized patients most prominently in the Roux-en-Y group. Also, cholecystokinin and somatostatin response differed significantly in favor of duodenal passage preservation after total gastrectomy. Cholecystokinin levels close to physiologic found at APwPDP reconstruction may contribute to a physiologic satiation in reconstructions with preserved duodenal passage after total gastrectomy

Localization of GAD-like immunoreactivity in the pancreas and stomach of the rat and mouse

The aim of this study was to localize cells immunoreactive for glutamate decarboxylase (GAD), the enzyme of GABA synthesis, in pyloric and oxyntic regions of the rat stomach as well as in the rat and mouse pancreas. GAD immunocytochemistry was carried out on polyethylene glycol or cryostat sections of alkaline paraformaldehyde fixed tissue, with simultaneous immunolabelling of various gastro-pancreatic hormones for topographical comparison. In the rat stomach, nerve fibers displaying intense GAD-like immunoreactivity were seen in the myenteric plexus, the circular muscular layer, the submucosa and the lamina propria of the mucosa. But, they were absent from the submucous plexus. Colchicine treatment of the rats allowed to detect some labelled perikarya in the myenteric plexus suggesting that the GABAergic innervation is at least partly intrinsic to the stomach. In the oxyntic and pyloric mucosa, endocrine cells appeared immunostained for GAD. However, the nature of their hormones remained unknown since double immunodetections revealed that they were immunoreactive neither for gastrin nor for somatostatin. In the rat and mouse pancreas, GAD-like immunoreactivity was found in islet cells which corresponded only to insulin-secreting cells. Somatostatin-, glucagon- and pancreatic polypeptide-immunopositive cells were devoid of GAD immunolabelling. No GAD-like immunoreactivity was detected in the exocrine tissue and innervation. These results strenghten the hypothesis that GABA is not only a neurotransmitter in the stomach but that it could also be an endocrine or paracrine factor in the stomach and pancreas