Changes in acid secretion over the years. A 30-year longitudinal study

The Effect of Cochinchina momordica Seed Extract on Gastric Acid Secretion and Morphologic Change in Aged Rat Stomach

Background/Aims

Cochinchina momordica seed extract (SK-MS10) has a gastric protective effect. We aimed to assess the effect of SK-MS10 on gastric acid secretion with morphologic changes in the aged rat.

Methods

Acid secretions were evaluated in the male F344 rats of four different ages (6-, 31-, 74-week, and 2-year). The 31-week-old rats were divided to three groups and continuously administered chow containing vehicle, SK-MS10 and lansoprazole, respectively. At the age of 74 weeks and 2 years, basal and stimulated acid was measured and the expression of mRNA and protein of H⁺-K⁺-ATPase were determined. The area of connective tissue of lamina propria was measured.

Results

Basal and stimulated gastric acid significantly decreased and connective tissue of lamina propria increased with age. The expression of mRNA and protein of H⁺-K⁺-ATPase significantly decreased with age. However, 74-week-old rats in the SK-MS10 group had higher stimulated gastric acid secretion than those in the vehicle and lansoprazole groups. In 2-year-old rats of SK-MS10 group, there was no increase of connective tissue.

Conclusions

As SK-MS10 kept the capacity of acid secretion as well as connective tissue area to comparable to young rats, it might valuable to perform further research regarding mechanism of SK-MS10 as an antiaging agent in the stomach.

[Safety and interactions of proton pump inhibitors: lessons learned in millions of patients]

After many years of widespread use, proton pump inhibitors (PPI) have been demonstrated to be relatively safe. The most frequently associated adverse reactions are mild with scarce clinical effects. These agents produce hypergastrinemia but this adverse effect has not been related to the development of malignancies. PPI seem to facilitate certain bacterial infections in the gastrointestinal and respiratory tracts. However, these infections are easily treated and therefore do not limit the prescription of PPI. From the pharmacokinetic point of view, the possibility of interactions with other drugs metabolized by the cytochrome P450 system has been described but these interactions generally seem to have little clinical or therapeutic importance. However, regulatory agencies are currently stressing the hypothetical interaction between PPI (especially omeprazole) and clopidogrel, which reduces the latter's antiplatelet effect. Although this recommendation should be followed, this interaction should be specifically evaluated to determine its clinical effect and the possible alternatives in patients at risk of gastrointestinal bleeding. Lastly, the present article reviews PPI administration in special, currently debated situations, such as in pregnant or breastfeeding women.

Long-term safety concerns with proton pump inhibitors

Proton pump inhibitors (PPIs) are among the most widely prescribed medications worldwide. Their use has resulted in dramatic improvements in treatment of peptic ulcer disease and gastroesophageal reflux disease. Despite an acceptable safety profile, mounting data demonstrate concerns about the long-term use of PPIs. To provide a comprehensive review regarding the concerns of long-term PPI use, a literature search was performed to identify pertinent original and review articles. Despite study shortcomings, the collective body of information overwhelmingly suggests an increased risk of infectious complications and nutritional deficiencies. Data regarding any increased risk in gastric or colon malignancy are less convincing. PPIs have revolutionized the management and complications of acid-related disorders with a high margin of safety; however, with the data available, efforts to reduce the dosing of or discontinue the use of PPIs must be reassessed frequently.

Control of gastric acid secretion in health and disease

Recent milestones in the understanding of gastric acid secretion and treatment of acid-peptic disorders include the (1) discovery of histamine H(2)-receptors and development of histamine H(2)-receptor antagonists, (2) identification of H(+)K(+)-ATPase as the parietal cell proton pump and development of proton pump inhibitors, and (3) identification of Helicobacter pylori as the major cause of duodenal ulcer and development of effective eradication regimens. This review emphasizes the importance and relevance of gastric acid secretion and its regulation in health and disease. We review the physiology and pathophysiology of acid secretion as well as evidence regarding its inhibition in the management of acid-related clinical conditions.

Influence of age and gender on gastric acid secretion as estimated by integrated acidity in patients referred for 24-hour ambulatory pH monitoring

OBJECTIVES

Earlier studies have suggested that gastric acid secretion declines with age. Integrated acidity (IA) calculated from ambulatory 24-h pH studies provides an estimation of gastric acid secretion that is less cumbersome than nasogastric aspiration. The aim of this study was to calculate IA as a function of age and gender.

METHODS

In a retrospective study, 753 ambulatory 24-h pH studies from 1994 to 2001 were analyzed. Subjects were classified according to nine age groups: <35 yr (n = 124), 35-39 yr (n = 90), 40-44 yr (n = 92), 45-49 yr (n = 111), 50-54 yr (n = 96), 55-59 yr (n = 61), 60-64 yr (n = 59), 65-69 yr (n = 42), and > or =70 yr (n = 64). Basal integrated acidity (BIA) was defined as IA between 12 midnight and 8 AM when no meals were consumed. Daytime and nocturnal IA/h was measured from 8 AM to 8 PM and from 8 PM to 8 AM. Postprandial IA (PIA) was measured for 2 h after the largest meal peak in each patient.

RESULTS

Gender distribution was similar between groups (chi(2) = 6.42, 3 df, p = 0.093). Mean gastric pH was similar between genders (2.96 +/- 1.36 women; 3.01 +/- 1.42 men; p = 0.71). Women and men had similar BIA (361.1 +/- 384.1 vs 434.6 +/- 436.6 mmol/L/h, p = 0.10), daytime IA (33.5 +/- 33.0 vs 34.1 +/- 33.7 mmol/L, p = 0.90) and nocturnal IA (43.3 +/- 42.1 vs 48.0 +/- 46.6 mmol/L, p = 0.42), and PIA (38.2 +/- 58.7 vs 36.0 +/- 58.5 mmol/L/h, p = 0.47). Mean gastric pH, daytime and nocturnal IA, BIA, and PIA did not differ between age groups (p > 0.1). None of the parameters studied had a linear association with age (mean gastric pH, r = 0.106; BIA, r = -0.124; daytime IA, r = -0.046; nocturnal IA, r = -0.104; PIA, r = -0.117).

CONCLUSIONS

Based on this study, we conclude that IA is unaffected by gender or age.

Proton pump inhibitors as a risk factor for Clostridium difficile diarrhoea

Clostridium difficile is the main infectious cause of colitis in hospital inpatients. The incidence is increasing, and it is associated with significant mortality, morbidity, and increased length of stay. The main risk factor is use of broad-spectrum antibiotics, and antibiotic restriction is the most effective control measure. We carried out a retrospective case-control study to investigate whether use of proton pump inhibitors (PPI) was an additional risk factor. PPI use within the preceding eight weeks was associated with an increased risk of C. difficile diarrhoea (odds ratio 2.5, 95% CI 1.5-4.2). Reduction of unnecessary PPI use may be an additional strategy to reduce the incidence of this infection.