Effect of various types of vagotomy on gastric secretion of histamine in dogs]

The chronic experiments on dogs with fundal fistulas have revealed that the partial stomach denervation (selective proximal, selective distal and subcardial vagotomies) decreases the gastric secretory responses caused by submaximal and maximal doses of histamine. Selective and extragastral vagotomies do not change the histamine gastric secretion in dogs, stimulated by the maximal histamine dose.     

Role of gastrin in duodenal mechanisms of inhibition of gastric secretion in the dog and man

Gastrin serum levels after acidification of the second portion of the duodenum were studied, in dogs and humans, while simultaneously measuring secretin levels and gastric acid secretion. After duodenal acidification in dogs, a 50% inhibition of gastric acid secretion with parallel 100% increases in the serum secretin levels was noted whereas gastrin serum levels did not change (after duodenal acidification). In humans, a 25% inhibition of gastric acid secretion with parallel 50% (not significative) increases in the secretin serum levels was noted. In the entire group gastrin levels did not change, but in 35.2% of the subjects a little increment without statistical significance was noted. It is concluded that the inhibition mechanism of gastric acid secretion after duodenal acidification is more important in dog than in man, and that, probably, gastrin does not play an important role in this mechanism.     

Endocrine cells of the gastric mucosa in patients with duodenal ulcer after vagotomy]

Bioptates of the stomach mucous membrane (SMM) have been investigated in 169 patients suffering from duodenal ulcer (DU). According to the nocturnal gastric secretion test among them there are "hypersecretors" and persons with moderate elevation of acid formation. In conformity with the efficiency of the operative treatment among the patients examined, groups are defined: those with recurrent disease and those recovered after vagotomy. The DU endocrine apparatus undergoes both qualitative and quantitative alterations after vagotomy. When recovery after vagotomy takes place, the number of endocrine cells only slightly exceeds these parameters in the patients with a moderately manifested acid production. These alterations are adaptive. The recurrence of DU in patients with moderately manifested acid production before the operation can be explained by hyperplasia of G-cells. A high degree of hyperplasia of all elements of the endocrine apparatus in the "hypersecretors" can be one of the causes of the DU recurrence. The data about the state of G-, Ec- and EcL-cells before and after vagotomy can be used at prognostication the results of surgical treatment of patients with DU.     

Changes in gastric mucosa after vagotomy and gastrojejunostomy for duodenal ulcer.

Gastric mucosa was studied histologically in 141 patients. Eighty two had undergone vagotomy and gastrojejunostomy between 15 and 25 years previously for duodenal ulcer, and 59 control patients had a long history (minimum 15 years) of duodenal ulcer treated medically. No carcinoma was found in either group. Two patients with severe dysplasia and 13 patients with moderate dysplasia were found in the study group, compared with none in the control group (p less than 0.01). Intestinal metaplasia was seen in 44 (53%) of the study group and 16 (27%) of the control group (p less than 0.01). Atrophy and gastritis were more severe (p less than 0.01 for atrophy; p = 0.05 for gastritis) in the study group. Gastric mucosal changes were more severe after surgical treatment for duodenal ulcer than after medical treatment, and possibly a high incidence of gastric carcinoma may occur 25 years after vagotomy and gastrojejunostomy.     

Effect of vagotomy on postcastration gonadotropin secretion in male rats

The postcastration increase in gonadotropins was studied in intact and vagotomized male rats. Rats underwent vagotomy or sham surgery immediately prior to castration. In the first experiment, rats were bled before castration and at 1, 2, 4, and 7 days after castration. Serum LH and FSH were significantly lower in vagotomized rats 1 day after castration. On days 2, 4, and 7 postcastration, serum gonadotropin levels were generally not different among experimental groups. In a second experiment, rats were decapitated at 12 or 24 hr after surgery and castration. Trunk blood was collected for assay of LH. Vagotomy had no effect on LH levels at 12 hr postcastration, but, at 24 hr postcastration, vagotomized rats had significantly lower serum LH than did sham-operated rats. These experiments indicate that vagotomy has a transient suppressive effect on gonadotropin release following castration. Such observations support the hypothesis that the vagus nerve may play a modulatory role in gonadotropin secretion.     

迷走神经切除对大鼠胃内UCP2 mRNA表达及胃酸分泌的影响

目的:观察整体大鼠胃酸分泌与ATP水平之间的关系及迷走神经对解偶联蛋白2(UCP2)mRNA表达的调节.方法:制备大鼠高选择性迷走神经切断模型.采用滴定法检测大鼠胃酸酸度,荧光测定法检测胃体组织内ATP含量,应用Northern blot法检测分析UCP2mRNA表达.结果:迷走神经切断后24 h,大鼠胃酸酸度显著降低,胃体组织内ATP含量下降.与假手术组相比,胃体组织UCP2 mRNA表达显著增加.结论:迷走神经切断后24 h大鼠胃体组织ATP含量下降;迷走神经下调胃体组织UCP2 mRNA表达.结果提示大鼠迷走神经可能通过抑制UCP2 mRNA表达,提高ATP含量,为质子泵泌酸提供能量来源.     

Effect of duodenal trypsin on pancreatic secretion in men

The effect of tryptic activity in duodenum on L-phenylalanine (100 mmol.1-1 intraduodenally) stimulated pancreatic secretion in 18 healthy volunteers has been evaluated. Intraduodenal infusion of trypsin (150 mg) during 1 h caused the reduction of alpha-amylase and lipase output by ca 30%. The infusion of aprotinin at the dose of 0.5.10(6) KIU during 30 min caused return of the alpha-amylase and lipase output to the pretryptic values. The infusion of trypsin in higher dose (300 mg) caused more pronounced decrease of amylase and lipase output (ca 45%). Our data indicate that active trypsin in duodenum is responsible for the inhibition of L-phenylalanine stimulated pancreatic enzyme secretion in man. These results corroborate the existence of feedback regulation of stimulated pancreatic secretion by intraduodenal trypsin in man.