What are the three main tests for gastric function

The three main indicators of gastric function are gastrin-17, pepsinogen I, and pepsinogen II, which are used to evaluate the functional status and health status of the gastric mucosa.

1. Gastrin-17:

Gastrin-17 is a hormone secreted by G cells in the antrum of the stomach, whose main function is to stimulate gastric acid secretion. When the gastric mucosa shrinks or becomes inflamed, the number of G cells decreases, leading to a decrease in gastrin-17 levels. Therefore, detecting gastrin-17 can help determine whether there is atrophic lesions in the gastric antral mucosa. If the indicator is low, it may indicate atrophy of the gastric antral mucosa and weakened gastric acid secretion ability. On the contrary, if the indicator significantly increases, it may be related to feedback hypergastrinemia caused by insufficient gastric acid secretion, and rare diseases such as gastrinoma need to be vigilant.

2. Pepsinogen I:

Pepsinogen I is mainly secreted by the main cells and mucous cells of the gastric fundus gland, and is a precursor of gastric protease. Its level can reflect the secretion function of the gastric fundus and gastric mucosa. When the gastric mucosa shrinks, the number of main cells decreases and the secretion of pepsinogen I decreases accordingly. Therefore, decreased levels of pepsinogen I are important serological markers for diagnosing atrophic gastritis of the gastric body. In addition, the ratio of this indicator to pepsinogen II has important reference value for evaluating the scope and severity of gastric mucosal atrophy.

3. Pepsinogen II:

Pepsinogen II is secreted by the gastric glands (including the cardia, fundus, antrum, and pylorus) and the Brunner gland in the upper duodenum. Unlike pepsinogen I, its secretion range is wider. When inflammation, erosion, or ulceration occurs in the gastric mucosa, the secretion of pepsinogen II will significantly increase. Therefore, an increase in this indicator usually indicates active inflammation or damage to the gastric mucosa. By combining the values of pepsinogen I and pepsinogen II, the ratio of pepsinogen I to pepsinogen II can be calculated to more accurately determine the location and degree of gastric mucosal atrophy, and help distinguish between gastric atrophy and antral atrophy. The three tests of gastric function (SEP) are usually used as important means for initial screening of gastric diseases and assessment of gastric mucosal status, especially for the initial screening of chronic gastritis, gastric ulcer, atrophic gastritis, and gastric cancer risk. It is recommended that the examinee have a light diet the night before the examination, avoid high-fat and high protein foods, and maintain an empty stomach on the day of the examination. If there are abnormalities in the examination results, it is necessary to consult a gastroenterologist in a timely manner, combine further examinations such as gastroscopy to clarify the diagnosis, and follow the doctor's advice for targeted treatment or regular follow-up.