Method for Studying Calcium Homeostasis at the Level of Gastroenteral Environment in Minipigs

Abstract

The stages of calcium metabolism at the enteric medium level were studied in experiments on minipigs. Atomic absorption spectrophotometry was used to determine the concentration of calcium in the endogenous and exogenous structures of the chyme while its passing through the small and large intestines, both in different layers of the intestinal wall and in the blood flowing in and out of the intestine. Regularities of changes in calcium concentration in chyme fractions and its predominant accumulation in the dense endogenous fraction in the small intestine were established. Taking into account the hydration of the glycoproteins of the abdominal mucus and its existence in the form of a kind of enteroplasm of the chyme, it is assumed that calcium is involved in the formation of endogenous structures and chyme as a whole by redistributing between soluble and fixed forms of the element. The dynamics of the increase in calcium concentration in the layer of mucous deposits from the distal to the proximal section of the intestinal wall was revealed. In the intestinal mucosa, the calcium concentration is generally lower, although the dynamics follows a similar pattern. The arterio-venous difference in the damage of the digestive tract indicates the predominant excretion of the element into the digestive cavity. The conclusion is made about the role of endogenous chyme structures in maintaining calcium homeostasis not only in the gastroenteric environment, but also in the body as a whole.