The effect of pharmacologically altered gastric pH on cadmium absorption from the diet and its accumulation in murine tissues Original paper

What was studied?

This study investigated the effect of pharmacologically altered gastric pH on the absorption of cadmium (Cd) from the diet and its subsequent accumulation in murine tissues. Specifically, the study focused on how increasing gastric pH using proton-pump inhibitors (omeprazole) and H2 receptor antagonists (cimetidine) influenced cadmium bioavailability. The research explored whether altering gastric pH could reduce the absorption of cadmium, which is a significant environmental and dietary contaminant known to cause kidney dysfunction, cancer, and other health issues. The experiment aimed to determine whether pharmacologically induced changes in gastric pH could decrease cadmium accumulation in organs such as the liver, kidneys, and intestines.

Who was studied?

The study used male CD1 mice as the experimental subjects. The mice were randomly assigned to five different groups, including a control group, a group receiving a cadmium-amended diet, and groups receiving cadmium-amended diets along with either omeprazole or cimetidine treatment. These treatments were administered via gavage over 14 days. The study assessed the bioaccumulation of cadmium in various tissues such as the liver, kidneys, testes, and small intestine, following the different treatments. This approach allowed the researchers to evaluate how gastric pH modulation influenced cadmium absorption and distribution in the body.

Most important findings

The study found that pharmacologically altering gastric pH influenced the bioavailability of dietary cadmium in mice. While omeprazole treatment increased gastric pH, it led to a decrease in cadmium accumulation in the small intestine. However, omeprazole-treated animals did not show a significant reduction in cadmium concentrations in the liver, kidneys, and testes. The study also observed that cimetidine treatment did not significantly alter the gastric pH or cadmium absorption compared to the control. Additionally, the in vitro analysis of cadmium solubility suggested that an increase in gastric pH decreased cadmium solubility, which may have contributed to the reduced absorption in the small intestine observed in omeprazole-treated animals. The study also noted that even though gastric pH changes affected the absorption in the small intestine, there was compensatory absorption of cadmium in the large intestine, leading to similar cadmium accumulation in organs like the liver and kidneys.

Key implications

This study has important implications for understanding the role of gastric pH in cadmium absorption and its potential for mitigating cadmium toxicity. The results suggest that while increasing gastric pH with proton-pump inhibitors like omeprazole may reduce cadmium absorption in the small intestine, it does not significantly affect the accumulation of cadmium in major organs. This finding suggests that the gastrointestinal tract, particularly the small intestine, may not be the only site of cadmium absorption. The compensatory uptake in the large intestine, as observed in this study, highlights the complex nature of cadmium bioavailability and its potential health impacts. The research also indicates that simply altering gastric pH may not be an effective strategy for reducing cadmium toxicity, as its effects persist in other tissues.