A Continuous Dietary Supply of Free Calcium Formate Negatively Affects the Parietal Cell Population and Gastric RNA Expression for H+/K+-ATPase in Weaning Pigs

Abstract

Baby formula acidification can be used to reduce diarrhea. Calcium formate is a dietary acidifier frequently used in animal weaning diets; it is also a source of available calcium. Gastric acidification reduces gastrin release and hydrochloric acid (HCl) secretion. To study the medium-term effects on fundic gastric mucosa, we fed weaning pigs control diets or diets supplemented with free or fat-protected calcium formate. We evaluated the following: 1) the number of HCl-secreting parietal cells, by immunohistochemistry using an antibody against H(+)/K(+)-ATPase; 2) the number of enteroendocrine cells immunohistochemically stained with chromogranin A (CGA), somatostatin, and histamine (HIS); and 3) the expression of the H(+)/K(+)-ATPase gene, by real-time RT-PCR in the oxyntic mucosa. Cells co-staining for CGA and HIS were defined as enterochromaffin-like (ECL) cells. Pigs fed calcium formate had fewer parietal cells and a lower expression of the H(+)/K(+)-ATPase gene than the controls (P < 0.05). This reduction did not occur in pigs fed fat-protected calcium formate. Somatostatin immune-reactive cells were also more numerous in pigs fed free calcium formate than in controls (P < 0.05). The number of ECL cells was not affected. Using covariance analysis, the number of parietal cells explained part of the differences in the expression of H(+)/K(+)-ATPase gene (positive correlation, r = 0.385, P < 0.01), and excluded the statistical significance of the diet. In the future, the effects on the oxyntic mucosa should be checked when the diet supplemented with calcium formate is discontinued. Furthermore, a reduction in the number of parietal cells could impair the absorption of vitamin B-12 due to a reduced secretion of the intrinsic factor by these cells.

Effects of dietary calcium formate inclusion on broiler performance, skeletal development, and gut maturation

“…Villus height was increased (P ≤ 0.05) on d 49 in the 1.0% CaFo group when compared with villus heights in all other treatments (Table 4). Although the mechanism for the increase in villus height was not determined in this study, it is known that organic acids do affect the gut microflora, which has a direct effect on the gut mucosa [12,29]. Calcium formate is known to control diarrhea in weaning pigs, possibly by preventing bacterial translocation and the resulting colonization by pathogens [13,29].…”

“…Calcium formate is known to control diarrhea in weaning pigs, possibly by preventing bacterial translocation and the resulting colonization by pathogens [13,29]. Organic acids are also known to affect gut pH, gastrin production, acid secretion, epithelial cell proliferation, and nutrient absorption, and they are bacteriostatic, which could have a possible effect on gut morphology as well [12,17,[29][30][31]. …”

Distribution, organization and innervation of gastric MALT in conventional piglet

“…This article describes pig gastric MALT, with particular attention given to the distribution of lymphoid structures in the cardiac mucosa of the diverticulum, the pyloric mucosa and the transitional sites from the cardiac to the oxyntic mucosa and from the cardiac to the pyloric mucosa. We did not consider the oxyntic mucosa of the corpus because we very rarely observed LFs in our previous studies designed to test the effects of different diets on weaned piglet gastric mucosa (Bosi et al. 2006; Mazzoni et al.…”

“…Masson’s trichrome stain was used for histological observation (McManus & Mowry, 1960). For immunohistochemistry, the avidin‐biotin‐peroxidase complex (ABC) method was used, as described elsewhere (Bosi et al. 2006).…”

Weaning — A challenge to gut physiologists

“…It decreased the number of HCl-secreting parietal cells and increased somatostatin-producing cells (somatostatin has a suppressive action on HCl secretion), and reduced H+/K+ ATPase gene expression (Bosi et al, 2006). Thus organic acids exert a negative feed-back on gastric acid secretion, an effect which may not be desirable in weaned piglets.…”