Estimation of ileal output of gastro-intestinal glycoprotein in weaned piglets using three different methods

Abstract

-Mucin is the main constituent of gastrointestinal mucus and is responsible for its physicochemical and physiological properties. Previous studies have suggested that this glycoprotein represents a major component of undigested endogenous protein at the ileum. The aim of the study was to estimate the ileal output of this glycoprotein using three methods: direct ELISA, hexosaminebased method and ethanol precipitation. For setting up the ELISA assay, the glycoprotein was isolated from intestinal mucus scraping by cesium chloride density gradient ultracentrifugation and a rabbit hyperimmune plasma was raised against the purified glycoprotein. Ileal outputs of hexosamine and glycoprotein were measured in weaned piglets fed a control diet (C) based on casein or diets which contained 50% crude protein supplied by white (WCP) or black (BCP) chickpea. The hexosamine output was higher (P < 0.05) with the WCP diet (2.3 and 1.5 g·kg -1 of dry matter intake for glucosamine and galactosamine, respectively) than with diet C (1.1 and 0.7 g·kg -1 of DMI). The hexosamine-based and ethanol precipitation methods, but not the ELISA, showed significant differences between the diet treatments (P < 0.05). Although hexosamine-based and ethanol precipitation methods for the estimation of ileal glycoprotein appeared to be more satisfactory than the developed ELISA to display diet effects in this study, it remains to be determined whether the higher glycoprotein data variability observed with ELISA reflects the actual biological variability of the phenomenon or not.small intestine / methods / glycoprotein / piglet

ORIGINAL ARTICLE: Ileal endogenous amino acid flow of broiler chickens under high ambient temperature

“…These amino acids also constitute a large proportion of mucous glycoprotein (Souffrant, 1991; Lien et al., 1997). Thus, mucin represents a major component of undigested endogenous protein at the ileum (Piel et al., 2004). The proportion of threonine (28–35%) and serine (13–16%) was enriched in mucin, which resulted in their high contribution to the endogenous excretion (Lien et al., 1997).…”

A moderate threonine deficiency affects gene expression profile, paracellular permeability and glucose absorption capacity in the ileum of piglets☆☆☆

“…The high rate of intestinal threonine extraction could be associated with protein synthesis [4] and especially with the synthesis of mucins [6][7][8] whose threonine content ranges from 13% to 26% of total AA [9][10][11]. Threonine deficiency could also impact on other functions of the small intestine.…”

Nondietary Gut Materials Interfere with the Determination of Dietary Fiber Digestibility in Growing Pigs When Using the Prosky Method ,

“…) (38). The crude microbial and crude mucin precipitates were freezedried, weighed, and kept at 220°C until further analysis.…”