Immune system stimulation increases the irreversible loss of cysteine to taurine, but not sulfate, in starter pigs

Abstract

An isotope tracer study was conducted to evaluate the effects of immune system stimulation (ISS) on the irreversible loss of cysteine (Cys) to taurine (Tau) and sulfate (SO4), as well as glutathione (GSH) synthesis, during the fed state in pigs. We previously have reported that ISS increases plasma Cys flux and the GSH synthesis rate at the tissue and whole-body levels in growing pigs. Thus, the current article presents the data on the irreversible loss of Cys during ISS in pigs. Ten gilts (BW: 7.0 ± 0.12 kg) were feed restricted a sulfur amino acids (SAA) limiting diet and injected twice with either saline (n = 4) or increasing amounts of E. coli lipopolysaccharide (n = 6). The day after the second injection, a 5-h primed continuous intravenous infusion of 35S-Cys was conducted. ISS reduced plasma Cys and total SAA concentrations (16% and 21%, respectively; P < 0.05). However, ISS had no effect on the plasma concentrations of Tau and SO4, nor did it affect the appearance of 35S in plasma Tau, plasma SO4, urinary Tau, or urinary SO4 (P > 0.19). On a whole-body basis and including urinary excretion, ISS increased the appearance of 35S in Tau by 67% (P < 0.05), but tended to decrease the appearance of 35S in SO4 by 22% (P < 0.09). Overall, the current findings indicate that during ISS, decreased plasma SAA concentrations and increased plasma Cys flux are attributed in part to increased rates of Cys conversion to Tau, but not Cys catabolism to SO4. Thus, increased utilization of Cys for the synthesis of immune system metabolites, such as GSH and Tau, is likely the main contributor to increased Cys flux during ISS in pigs. In addition, the irreversible loss of Cys during ISS is small and has a minimal impact on the daily SAA requirements of starter pigs.

Taurine stimulates protein synthesis and proliferation of C2C12 myoblast cells through the PI3K-ARID4B-mTOR pathway

“…High concentrations of Tau (higher than 120 μM) had opposite effects. Recent reports show that the plasma concentrations of Tau in starter pigs are ranged from 40 to 50 μM (42) , while those in Huanjiang minipigs during gestation period are ranged from 110 to 135 μM (43) . The plasma Tau concentrations of dogs fed a nutrient-fortified endurance diet containing 0•34 % Tau over several months were ranged from 145 to 180 μM, which were markedly higher than those of the control fed a diet containing 0•07 % Tau (ranged from 60 to 90 μM) (44) .…”

217 Comparative Effects of Dietary Methionine and Cysteine Supplementation on Redox Status and Intestinal Integrity in Immunologically Challenged-weaned Pigs

“…This is partially supported by a study by Castellano et al (Castellano et al 2015) in which a Met-de cient diet lowered the level of GSH in the muscle in growing pigs. Cys is the rate-limiting substrate for GSH synthesis, and the plasma Cys ux increases mainly for the higher GSH turnover when the immune system is stimulated in pigs (Rakhshandeh et al 2020). This re ects that dietary Cys supplementation may help replenish the depleted GSH under oxidative stress conditions.…”

“…Isotopic tracer research indicated that 20% and 25% of dietary Met and Cys were metabolized by the intestine, respectively (Riedijk et al 2007;Bauchart-Thevret et al 2011). This re ects the high demands for methyl donors, GSH, and Cys-rich protein (e.g., mucins and defensins) by the intestinal epithelial cells in response to exogenous toxins and pathogens (Bauchart-Thevret et al 2009a; Rakhshandeh et al 2020). During the acute phase of in ammation, SAA metabolism increases mainly because of the increased demand for acute-phase proteins and GSH (Rakhshandeh et al 2019;Rakhshandeh et al 2020).…”

“…This re ects the high demands for methyl donors, GSH, and Cys-rich protein (e.g., mucins and defensins) by the intestinal epithelial cells in response to exogenous toxins and pathogens (Bauchart-Thevret et al 2009a; Rakhshandeh et al 2020). During the acute phase of in ammation, SAA metabolism increases mainly because of the increased demand for acute-phase proteins and GSH (Rakhshandeh et al 2019;Rakhshandeh et al 2020). Dietary SAA for protein deposition (growth) is redirected toward mounting an immune response, suggesting greater dietary SAA requirement for optimal growth (Litvak et al 2013;Rakhshandeh et al 2014).…”