Transport and expression of transporters for 3-O-methyl-D-glucose and L-methionine along the intestine of broiler chickens receiving different methionine supplements

Abstract

The present study hypothesized that supplementation of different methionine (Met) sources might influence the intestinal absorption of L-Met and 3-O-methyl-D-glucose (3-OMG) in broilers. In a completely randomized study, a total of 53 Cobb500 broilers (30 males and 23 females) received a grower-finisher diet that was either not supplemented with Met (Met + Cys, 0.49 %; control) or supplemented with either 0.27 % L-Met, 0.27 % DL-Met or 0.47 % DL-2‑hydroxy-4-(methylthio) butanoic acid (HMTBA). After ≥10 days on the diets, uptakes of 3-OMG and L-Met were measured in duodenum, mid-jejunum and caecum at 50 µM and 5 mM concentrations in Ussing chambers, each in the presence and absence of Na⁺. We also investigated the mRNA expression of apical glucose and Met transporters. Dietary supplements had no effect on 3-OMG and L-Met uptakes (P > 0.05), except for male broilers receiving DL-Met or DL-HMTBA, that showed higher jejunal uptakes of L-Met than control at 5 mM (P < 0.001). Except for L-Met uptakes at 5 mM, tissue × sodium interactions (P ≤ 0.05) for 3-OMG and L-Met uptakes verified higher uptakes in jejunum compared to duodenum and caecum; with higher uptakes in the presence vs. absence of Na⁺ in jejunum only. In duodenum, uptakes of L-Met and 3-OMG at 50 µM concentration were higher in males vs. females. Expression of SGLT1, B⁰AT1, ATB^0,+ and rBAT, but not ASCT1, were lowest in caecum (P ≤ 0.05). Expression of B⁰AT1 was higher in males vs. females (P ≤ 0.05). Expression of ASCT1 was higher with DL-Met and DL-HMTBA supplements compared to L-Met and control (P ≤ 0.05). These findings indicate that jejunum is the main intestinal segment for Na⁺-dependent L-Met and 3-OMG absorption in broilers with minor effects of dietary Met source. A sexual dimorphism for duodenal nutrient uptake and mRNA abundance of B⁰AT1 was congruent with the more efficient growth performance of male chickens known from the literature.

Keywords: 3-O-methyl-D-glucose; Broiler; Intestinal absorption; Methionine supplementation; Ussing chamber.

Fig. 1

Graphical sketch of the experimental design. See text for details. ASCT1 = Neutral amino acid transporter A; ATB^0,+ = Amino acid transporter B^0,+; B⁰AT1 = B⁰ amino acid transporter 1; HMTBA = 2-hydroxy-4-(methylthio) butanoic acid; Met = methionine; 3-OMG = 3-O methyl-d-glucose; rBAT = heavy chain of neutral and basic amino acid transport protein; SGLT1 = Sodium-d-glucose linked transporter 1; suppl. = supplement. Created in BioRender. Aschenbach, J. (2025) https://BioRender.com/41v0ewb.

Fig. 2

Uptakes of 3-O methyl-d-glucose (3-OMG) at a final concentration of 50 µM and 5 mM. Columns represent least square means ± CI from n = 19 - 30 chickens. Three-way ANOVA and post hoc Student-Newman-Keuls' test were used to compare the factors tissue, sodium, sex and their two- and three-way interactions. DUO = duodenum; JEJ = jejunum; CAE = caecum; NMDG = N-methyl-d-glucamine.

Fig. 3

Uptakes of l-methionine (L-Met) at a final concentration of 50 µM and 5 mM. Columns represent least square means ± CI from n = 19 - 30 chickens. Three-way ANOVA and post hoc Student-Newman-Keuls' test were used to compare the factors sodium, tissue, sex and their two- and three-way interactions. DUO = duodenum; JEJ = jejunum; CAE = caecum; NMDG = N-methyl-d-glucamine.

Fig. 4

Three-way interaction of uptakes of l-methionine (L-Met) at a final concentration of 5 mM for the factors tissue, diet and sex as further isolated by post hoc Student-Newman-Keuls' test in jejunum of male chickens. Columns represent least square means ± CI from n = 6 - 8 chickens. Data for female chickens in jejunum and for male and female chickens in duodenum and caecum are not shown because they did not show diet-dependent differences (P > 0.05). HMTBA = 2-hydroxy-4-(methylthio) butanoic acid.

Fig. 5

mRNA expression of selected glucose and methionine transporters in duodenum, jejunum and caecum using RT-qPCR from n = 5 - 8 chickens. Data was compared using three-way ANOVA (factors tissue, diet and sex) and post hoc Student-Newman-Keuls' test. DUO = duodenum; JEJ = jejunum; CAE = caecum; Met = methionine; HMTBA = 2-hydroxy-4-(methylthio) butanoic acid; SGLT1= Sodium-d-glucose linked transporter 1; B⁰AT1 = B⁰ amino acid transporter 1; ATB^0,+ = Amino acid transporter B^0,+; ASCT1 = Neutral amino acid transporter A; rBAT = heavy chain of neutral and basic amino acid transport protein.