Definition for idiopathic gastric acid hypersecretion

Zollinger-Ellison syndrome and other gastric acid hypersecretory states in which a specific etiology is identified are defined as a basal acid output of greater than 15.0 meq/hr. To determine the level of basal acid output that defines idiopathic gastric hypersecretion, basal acid outputs were investigated in normal subjects and patients with duodenal ulcers, and functional and statistical definitions for idiopathic gastric acid hypersecretion were developed. Sixty-five normal subjects were evaluated to define idiopathic gastric acid hypersecretion on a statistical basis, and 22 patients with refractory duodenal ulcers were evaluated to define idiopathic gastric acid hypersecretion on a functional basis. Mean basal acid output for the 65 normal subjects was 3.0±2.7 meq/hr. Even though the mean basal acid output for the group of 28 normal male subjects was slightly higher than for the group of 37 normal female subjects, the groups were not significantly different. The 95% confidence interval around the mean basal acid output for all normal subjects was 2.4–3.7 meq/hr, with little difference between the male and female groups. The mean basal acid output plus two standard deviations and the mean basal acid output plus three standard deviations for the 65 normal subjects were 8.4 meq/hr and 11.1 meq/hr, respectively. Of 109 patients with active duodenal ulcers treated for eight weeks with standard doses of antisecretory medication, 22 showed no healing as documented by endoscopy. The mean basal acid output for these 22 patients with nonhealed duodenal ulcers was 18.7 meq/hr (range 10.1–49.1 meq/hr) while mean basal acid output for the 87 patients with healed duodenal ulcers was 7.5 meq/hr (range 0.0–27.9 meq/hr). The difference in mean basal acid output between these two groups was statistically different (P<0.001). All patients with refractory duodenal ulcers had basal acid outputs of greater than 10.0 meq/hr. Our results indicate that the definition for idiopathic gastric acid hypersecretion should be a basal acid output of greater than 10.0 meq/hr, since, based on refractory duodenal ulcer disease, the functional definition for idiopathic gastric acid hypersecretion is a basal acid output of greater than 10.0 meq/hr, which in our data also corresponds well to the statistically defined range of basal acid output in normal subjects.     

Ranitidine therapy in patients with idiopathic gastric acid hypersecretion

One hundred twenty-four patients with idiopathic gastric acid hypersecretion (basal acid output greater than 10.0 meq/hr) were prospectively evaluated and treated with ranitidine twice a day. Fifty-four patients (44%) required standard doses of ranitidine 300 mg/day for adequate treatment, and the other 70 patients (56%) required increased doses of ranitidine (mean 994 mg/day, range 600–3000 mg/day). Mean basal acid outputs for these two groups were 14.0 and 16.6 meq/hr, respectively, which were not significantly different. Nevertheless, there was a significant correlation between basal acid output and daily ranitidine dose required for therapy (r=0.18,P=0.05). The duration of ranitidine therapy consisted of: <1 year (N=46), 1 year (N=16), 2 years (N=19), 3 years (N=22), 4 years (N=15), 5 years (N=6). Only five patients required progressive increases in ranitidine during the time of treatment, which consisted of an average of 0.5 dose adjustments per year. No side effects occurred with any of these high doses of ranitidine. These results indicate that, as in Zollinger-Ellison syndrome, ranitidine is effective therapy for patients with idiopathic gastric acid hypersecretion; however, markedly increased doses as large as 3000 mg/day may be required.     

Basal acid output and gastric acid hypersecretion in gastroesophageal reflux disease

The purpose of this study was to evaluate possible differences in basal gastric acid secretion with regard to severity of gastroesophageal reflux disease. Basal acid output was determined by nasogastric suction in 228 patients with gastroesophageal reflux disease who received upper gastrointestinal endoscopy and were diagnosed with either pyrosis alone (N = 98), erosive esophagitis with or without pyrosis (N = 87), or Barrett's esophagus (N = 43). Mean basal acid output for the 228 patients with gastroesophageal reflux disease was 6.5 ± 5.6 meq/hr, which was significantly different from 65 normal subjects with a mean basal acid output of 3.0 ± 2.7 meq/hr (P < 0.0001). Compared to normal subjects, mean basal acid outputs significantly differed for patients with pyrosis (P < 0.05), esophagitis (P < 0.01), and Barrett's esophagus (P < 0.01). There was also a significant difference in mean basal acid output between the patients with pyrosis and Barrett's esophagus (P < 0.01). Nineteen of the 98 patients with pyrosis (19%), 24 of the 87 patients with esophagitis (28%), and 15 of the 43 patients with Barrett's esophagus (35%) had gastric acid hypersecretion (basal acid output greater than 10.0 meq/hr). One hundred forty-six patients with gastroesophageal reflux disease were treated with ranitidine in doses that resulted in complete healing of esophagitis and disappearance of pyrosis. Ninety-three patients responded to ranitidine 300 mg/day; however, 53 patients required increased dose of ranitidine (mean 1205 mg/day, range 600–3000 mg/day). There was a significant correlation between basal acid output and daily ranitidine dose required for therapy for the 146 patients with gastroesophageal reflux disease (r = 0.53,P = 0.0001). Furthermore, a significant association was also found between the presence of gastric acid hypersecretion and the requirement for increased doses of ranitidine (greater than 300 mg/day) (P = 0.00001). These results indicate that there is a subset of patients with gastroesophageal reflux disease who do have idiopathic gastric acid hypersecretion. Moreover, these patients have an apparently higher requirement for medication dosage in order to achieve therapeutic efficacy.     

Zollinger-Ellison phenotype in the absence of hypergastrinemia and islet-cell tumor

Patients with the Zollinger-Ellison syndrome are characterized by islet-cell tumors, striking gastric acid hypersecretion, and peptic ulcer disease. They often experience severe abdominal pain, diarrhea, and gastrointestinal bleeding with potentially life-threatening consequences. It is a rare syndrome caused by nonbeta cell islet-cell tumors (gastrinomas) located in or in proximity to the pancreas. These tumors freely secrete gastrin, a peptide hormone that serves as a powerful stimulant of gastric acid secretion. Exuberant secretion of gastrin from the gastrinomas produces severe gastric acid hypersecretion that often leads to impressive peptic ulcer disease and the constellation of symptoms listed above. We describe a patient presenting with clinical manifestations characteristic of the ZES with strikingly elevated gastric acid secretion, multiple ulcers in the first and second portions of the duodenum and diarrhea, but in absence of islet-cell tumor and/or hypergastrinemia.     

Helicobacter pylori infection

Summary The present report describes two patients with fasting hypergastrinemia, gastric acid hypersecretion, andHelicobacter pylori gastritis. Provocative testing for Zollinger-Ellison syndrome was negative and imaging studies did not demonstrate an intra-abdominal mass. Following eradication of theHelicobacter pylori infection, the fasting hypergastrinemia resolved in both patients and in one patient the gastric acid hypersecretion also resolved. The implications of this case on the differential diagnosis of Zollinger-Ellison syndrome are discussed.     

质子泵抑制剂与酸反跳

酸反跳(rebound acid hypersecretion)指停用抑酸药物后胃酸分泌增加超过治疗前水平.质子泵抑制剂(proton pump inhibitors,PPIs)作为一代抑酸药物,比H2受体阻滞剂(histamine-2receptor antagonists,H2RA)具有更强的抑酸效果,是治疗酸相关疾病的主要药物.目前研究已经证实,PPIs可致酸反跳发生.PPIs的酸反跳可以再次诱发酸相关症状出现,不仅增加医疗预算,也给PPIs治疗的终止带来问题.高胃泌素血症是导致酸反跳现象的重要机制.正确使用PPIs,严格掌握适应证,探讨在有效治疗酸相关疾病的同时减少酸反跳发生的措施.     

Gastric acid response to modified sham feeding in patients with duodenal ulcer: Is increased vagal tone the cause of basal acid hypersecretion?

In order to test the hypothesis that increased basal vagal tone causes basal acid hypersecretion in duodenal ulcer (DU), the effect of sham feeding on gastric acid secretion was studied in 26 patients with DU and 20 healthy controls. Basal acid output (BAO), sham feeding-stimulated acid output (SAO) and peak histamine-stimulated acid output (PAO) were significantly higher in DU patients compared with healthy controls (P less than 0.01). The BAO/PAO ratio in DU patients (0.28 +/- 0.03) was not significantly different from that of healthy subjects (0.19 +/- 0.03), indicating that the higher BAO in DU patients group, as a whole, was due to a higher parietal cell mass. The basal subtracted response to sham feeding expressed as a fraction of secretory capacity [(SAO-BAO)/PAO], which correlates inversely with the basal vagal tone, was not significantly different in the patients and control subjects (0.27 +/- 0.03 versus 0.3 +/- 0.03; P greater than 0.05). Based on the data from the healthy controls, a ratio of BAO/PAO greater than 0.44 was defined as abnormal (using 95% confidence limits) and it indicated marked basal acid hypersecretion. Four of 26 DU patients had basal acid hypersecretion (that is, BAO/PAO greater than 0.44), but only two of them did not show an increase over their basal rate of secretion in response to sham feeding. All other DU patients, including two with marked basal acid hypersecretion, and all healthy controls showed an appreciable increase in their acid secretion in response to sham feeding.(ABSTRACT TRUNCATED AT 250 WORDS)     

Helicobacter pylori in duodenal ulcer patients with idiopathic gastric acid hypersecretion

Thirty-three consecutive patients with idiopathic gastric acid hypersecretion (defined as a basal acid output >10.0 meq/hr with a normal fasting serum gastrin level and negative secretin stimulation test) who were being treated for duodenal ulcer disease and other acid-peptic disorders were evaluated for the presence ofHelicobacter pylori by means of a rapid urease test. Fourteen patients had duodenal ulcer and 19 had other acid-peptic disorders (gastroesophageal reflux in 14, including six with Barrett's esophagus; four with nonulcer dyspepsia; and one with erosive gastritis).Helicobacter pylori was present in 12 of the 14 ulcer patients (86%) compared to only two of the 19 nonulcer patients (11%) (P<0.0001). The distribution of basal acid output for patients with duodenal ulcer was similar to that for nonulcer patients, and no significant difference in the mean basal acid output was found amongHelicobacter pylori-positive compared toHelicobacter pylori-negative patients. Seven of the duodenal ulcer patients with a basal acid output greater than 15.0 meq/hr wereHelicobacter pylori-positive, suggesting that the organism can withstand even extreme levels of gastric acidity. In conclusion, this study demonstrates that the prevalence ofHelicobacter pylori infection in patients with duodenal ulcer disease associated with idiopathic gastric acid hypersecretion is not different from a majority of ulcer patients with normal acid secretory profiles and offers additional evidence that extreme levels of gastric acid are not bactericidal for the organism.     

Bile acid inhibits tetragastrin-stimulated gastric secretion after Roux-en-Y biliary diversion in dogs

The present study was carried out to investigate the effect of several bile acids on tetragastrin-stimulated gastric secretion in dogs in which diversion of the biliary system was performed. Cholecystojejunostomy of the Roux-en-Y type was performed, along with the creation of a Heidenhain pouch (HP) and an external duodenal fistula. Gastric juice was collected from the HP and a mixture of bile acids and corn oil was administered through the duodenal fistula. Ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) exerted an inhibitory effect on gastric hypersecretion. Conjugated UDCA and several bile acids with different hydroxyl groups were also examined, and these bile acids also showed evidence of an inhibitory effect on the secretion of gastric juice, although there were no significant differences between them. Thus, it appears that all bile acids inhibit tetragastrin-stimulated gastric hypersecretion. This finding suggests that peptic ulcer disease can be prevented by the administration of bile acids to patients who undergo biliary diversion and are at a high risk for this postoperative complication.     

Comparison of omeprazole and ranitidine in treatment of refractory gastroesophageal reflux disease in patients with gastric acid hypersecretion

Secretion of gastric acid and volume, serum gastrin concentration, and ambulatory 24-hr esophageal pH monitoring were evaluated prospectively in 12 patients with idiopathic gastric acid hypersecretion (basal acid output greater than 10.0 meq/hr) undergoing treatment for refractory chronic long-standing pyrosis. Treatment lasted six months and consisted of three months of ranitidine (mean 2150 mg/day, range 1200–3000 mg/day), followed by three months of omeprazole (mean 33 mg/day, range 20–60 mg/day). Both ranitidine and omeprazole significantly reduced gastric acid output (P<0.001) and gastric volume output (P<0.001) compared to a basal evaluation and resulted in complete disappearance of pyrosis. Total reflux time (percent 24 hr intraesophageal pH less than 4) was significantly reduced by ranitidine (P<0.02) and omeprazole (P<0.001) compared to basal evaluation; however, the effects of omeprazole were significantly greater than ranitidine (P<0.05). Omeprazole caused a significant increase in serum gastrin concentration compared to both basal and ranitidine (P<0.05). Endoscopically documented erosive esophagitis was present in nine of the 12 patients, and seven of the 12 patients had Barrett's epithelium. All 12 patients had complete resolution of pyrosis and healed esophagitis by six months, but no significant endoscopic regression was observed in the extent of Barrett's epithelium. No side effects occurred with these high doses of ranitidine or omeprazole. These results indicate that high-dose ranitidine and omeprazole are effective therapy for refractory gastroesophageal reflux disease. However, with omeprazole, total reflux times are reduced more than with ranitidine, often into the normal range. That marked reduction of gastric acid secretion with omeprazole, which greatly reduces total reflux times, accounts for the significant elevation of serum gastrin concentration seen during omeprazole therapy.     

正常及病理状态胃粘膜神经内分泌细胞的超微定量分析

目的研究正常及病理状态包括十二指肠溃疡(DU)及 Zollinger-Ellison 综合征(ZES)胃粘膜神经内分泌细胞(NE)的超微定量分析.方法 8例正常标本,6例 DU 及5例 ZES 标本.用透射电镜及超微定量分析仪对其胃粘膜的神经内分泌细胞的各类超微定量参数进行测量.结果正常胃窦及胃体 NE 细胞密度分别为1.6%及0.9%,DU 为1.3%及0.8%(P>0.05).DU 胃窦 G 细胞占65%(P>0.05),D 细胞减少(占3%,P<0.01).胃体 ECL 细胞增多(占49%,P<0.05);D 细胞减少(占2%,P<0.01),EC 细胞减少(占4%.P<0.05),D 细胞的单位计数明显下降(P<0.01);胞浆比例明显增大(P<0.01).ZES 胃体 NE 细胞密度明显增高(为3.2%,P<0.01).其中 ECL 细胞明显增多(占65%,P<0.01);D 细胞明显减少(占4%,P<0.01).结论在 DU 及 ZES 中,NE 细胞的数量及种类都发生了变化,其中 D 细胞的减少及生长抑素的分泌下降可能是导致胃泌素升高的原因.     

Vagally mediated acid hypersecretion and lesion formation in anesthetized rat under hypothermic conditions

The pathophysiological changes associated with hypothermia were investigated in the rat stomach under anesthetized conditions. The animal was placed in a styrene foam box and the core body temperature was kept between 24 and 36°C using a heat lamp and refrigerant pack. Lowering of body temperature (<30°C) produced acid hypersecretion and induced hemorrhagic lesions in the gastric mucosa; these responses reached the maximum at 28°C, and a significant relationship was found between acid output and lesion score. Hypothermia (28°C) also caused a marked increase of gastric contractile activity and mucosal blood flow (MBF), but the ratio of acid output to MBF became greater when compared to that obtained under normothermic conditions. These changes induced by hypothermia (28°C) were completely blocked by vagotomy and were significantly inhibited by atropine, hexamethonium, clonidine, or TRH antiserum. However, lowering body temperature did not significantly affect acid secretory, motility, and ulcerogenic responses induced by carbachol in the vagotomized rat, excluding local mechanisms (suppression of the inhibitory nerves) in the hypothermia-induced changes. We conclude that hypothermia alone stimulates vagally dependent acid secretion and motility, resulting in damage in the gastric mucosa. These changes may be centrally mediated by TRH, which is released in association with the thermogenic response to hypothermia.     

胃溃疡大鼠胃粘膜血流量与泌酸变化的研究

用手术将十二指肠内容物持续胃内反流制成大鼠胃溃疡及经转流后的溃疡愈合模型进行研究。结果表明,溃疡组于胃窦小弯侧可见8.84±3.08(m~2)~(-3)的慢性溃疡形成,并显示胃粘膜血流量降低,G细胞密度、壁细胞数增加。溃疡愈合组经转流后大部分溃疡已愈合,G细胞密度、壁细胞数降低,粘膜血流量增加。本实验提示,泌酸细胞增多,泌酸量增加和胃粘膜缺血可能是溃疡形成的重要因素,增加胃粘膜的血液供应,降低胃酸分泌可促进溃疡愈合。     

弥漫性泛细支气管炎气道黏液高分泌的研究进展

弥漫性泛细支气管炎是一种小气道慢性炎症性疾病，气道黏液高分泌即痰液增多是该病主要临床表现之一。其黏液高分泌的机制至今尚不清楚，相关研究表明与绿脓杆菌、中性粒细胞、炎症介质及黏蛋白基因的多态性有关。另外，大环内酯类抗生素对弥漫性泛细支气管炎的气道高分泌有显著治疗作用。     

Physiological and clinical significance of enterochromaffin-like cell activation in the regulation of gastric acid secretion

Gastric acid plays an important role in digesting food （especially protein）, iron absorption, and destroying swallowed micro-organisms. H＋ is secreted by the oxyntic parietal cells and its secretion is regulated by endocrine, neurocrine and paracrine mechanisms. Gastrin released from the antral G cell is the principal physiological stimulus of gastric acid secretion. Activation of the enterochromaffin-like （ECL） cell is accepted as the main source of histamine participating in the regulation of acid secretion and is functionally and trophically controlled by gastrin, which is mediated by gastrin/CCK-2 receptors expressed on the ECL cell. However, longterm hypergastrinemia will induce ECL cell hyperplasia and probably carcinoids. Clinically, potent inhibitors of acid secretion have been prescribed widely to patients with acid-related disorders. Long-term potent acid inhibition evokes a marked increase in plasma gastdn levels, leading to enlargement of oxyntic mucosa with ECL cell hyperplasia. Accordingly, the induction of ECL cell hyperplasia and carcinoids remains a topic of considerable concern, especially in long-term use. In addition, the activation of ECL cells also induces another clinical concem, i.e., rebound acid hypersecretion after acid inhibition. Recent experimental and clinical findings indicate that the activation of ECL cells plays a critical role both physiologically and dinically in the regulation of gastric acid secretion.     

哮喘黏液高分泌研究进展

哮喘是一种以慢性气道炎症和黏液高分泌为特点的疾病,但黏液的过度分泌在哮喘病理生理中的作用被相对低估了。实际上黏液栓塞对气流受限及气道高反应有相当的影响,严重关系到哮喘的发病率和死亡率。哮喘患者分泌的黏液中主要表现为MUC5AC、MUC5B和MUC2的过度表达,哮喘相关的炎性介质也参与了哮喘黏液高分泌的调控。EGFR级联反应是许多不同刺激导致黏液分泌的共同路径,这些刺激主要包括氧化应激、蛋白酶和细胞因子等。在这些领域的研究有助于我们发现新的抗黏液高分泌药物,并借此加强对哮喘的治疗,提高哮喘患者生活质量。本文从哮喘黏液高分泌特点、调控机制和药物治疗等方面对哮喘黏液高分泌进行综述。     

Gastric luminal somatostatin secretion of normals and patients with pernicious anemia and with Zollinger-Ellison syndrome

We studied the release of gastric luminal somatostatin-like immunoreactivity (SLI) in response to a pentagastrin infusion (0.9 g/kg/hr, intravenous) in five normal volunteers, five patients with pernicious anemia, and two patients with Zollinger-Ellison syndrome. In addition, we studied the gastric luminal SLI secretion in response to a gastric luminal acid perfusion in two patients with pernicious anemia. Our results have shown that: (1)pentagastrin caused a parallel increase in luminal hydrogen ions and SLI release in normal volunteers; (2) Zollinger-Ellison patients had elevated basal acid and SLI levels that did not increase further with pentagastrin; (3) pentagastrin did not increase gastric acid or luminal SLI secretion in pernicious anemia patients; and (4) in pernicious anemia patients, a gastric luminal acid perfusion caused a significant increase in gastric luminal SLI over baseline values. In conclusion, gastric luminal hydrochloric acid appears to be a factor which stimulates the secretion of luminal SLI in human beings.This study was supported by the Gastroenterology Section Research Fund.This study was presented at the annual meeting of the American Gastroenterological Association in Chicago, Illinois, in May 1987.     

氧化应激与支气管哮喘气道黏液高分泌研究进展

哮喘是一种以支气管收缩可逆性、肺部炎症及气道重塑为特点的慢性气道炎症性疾病.黏液过度分泌导致气道阻塞、肺功能下降、气道重塑和感染增加.过度的活性氧/活性氮(ROS/RNS)产生造成气道炎症,气道高反应性,气道微血管高通透性和气道黏液高分泌,以及组织损伤和形态的改变.减轻氧化应激或增加抗氧化能够减轻气道嗜酸粒细胞,减少黏液分泌,减轻支气管高反应性.本文就氧化应激与哮喘气道黏液高分泌的关系作一综述.