Manganese source affects manganese transport and gene expression of divalent metal transporter 1 in the small intestine of broilers

Abstract

In the present study, two experiments were conducted to investigate the effect of Mn source on Mn transport and the expression of a Mn transporter, divalent metal transporter 1 (DMT1), in the small intestine of broilers. In Expt 1, in situ ligated duodenal loops from Mn-deficient chicks (29-d-old) were perfused with solutions containing 0 -8·74 mmol Mn/l from either MnSO 4 , or one of two organic chelates of Mn and amino acids with moderate (OM) or strong (OS) chelation strength (Q f ) up to 30 min. In Expt 2, Mn-deficient intact broilers (14-d-old) were fed a control diet (12·45 mg Mn/kg) or the control diet supplemented with 100 mg Mn/kg as one of all Mn sources for 14 d. The uptake kinetics of Mn from different Mn sources in the ligated duodenal loops followed a saturable process as determined by regression analysis of concentration-dependent uptake rates. The maximum transport rate (J max ) and K m values, and DMT1 mRNA levels in the ligated duodenal loops were higher (P,0·01) for OM and OS than for MnSO 4 . DMT1 mRNA levels were much higher (P, 0·01) in the duodenum than in the jejunum and ileum. Both DMT1 mRNA levels in the duodenum and plasma Mn contents from the hepatic portal vein of intact chicks on day 14 post-feeding increased (P,0·05) in the following order: control , MnSO 4 , OM , OS. These results indicated that organic Mn sources with stronger Q f showed higher Mn transport and absorption, and DMT1 might be involved in the regulation of organic Mn transport in the proximal small intestine of broilers.

Effect of dietary manganese on antioxidant status and expression levels of heat-shock proteins and factors in tissues of laying broiler breeders under normal and high environmental temperatures

“…Specifically, the organic Mn with moderate chelation strength demonstrated greater bioavailability than the inorganic Mn in bone. A series of studies also suggest that organic Mn has higher absorption and bioavailability than inorganic Mn for broilers (13)(14)(15)(16)28,29) and lambs (30) , and organic Mn sources with moderate chelation strengths exhibit the greatest availability (13)(14)(15) . Heat stress is believed to produce ROS and induce oxidative damage in broilers (31,32) and laying hens (6) .…”

“…Mn is a crucial component of the metalloenzyme manganese superoxide dismutase (MnSOD) (9) , which has a key role in the detoxification of superoxide free radicals. A series of studies in our laboratory have demonstrated that dietary Mn may increase heart MnSOD activity and reduce lipid peroxidation in broilers (10,11) and commercial laying hens (12) , as well as up-regulate heart MnSOD expression (13)(14)(15)(16) in broilers under * Corresponding author: X.-G. Luo, fax +86 10 62810184, email wlysz@263.net † These authors contributed equally to the present work.Abbreviations: CON, Mn-unsupplemented basal diet; CuZnSOD, copper zinc superoxide dismutase; HSF1 and HSF3, heat-shock factors 1 and 3; HSP70 and HSP90, heat-shock proteins 70 and 90; HT, high temperature; iMn, basal diet supplemented with 120 mg Mn/kg as inorganic Mn; MDA, malondialdehyde; MnSOD, manganese superoxide dismutase; NT, normal temperature; oMn, basal diet supplemented with 120 mg Mn/kg as organic Mn; ROS, reactive oxygen species; SOD, superoxide dismutase. …”

“…Mn is a crucial component of the metalloenzyme manganese superoxide dismutase (MnSOD) (9) , which has a key role in the detoxification of superoxide free radicals. A series of studies in our laboratory have demonstrated that dietary Mn may increase heart MnSOD activity and reduce lipid peroxidation in broilers (10,11) and commercial laying hens (12) , as well as up-regulate heart MnSOD expression (13)(14)(15)(16) in broilers under thermoneutral conditions. In addition, moderately chelated organic Mn is the most effective in augmenting these activities.…”

Manganese and Its Role in Poultry Nutrition: An Overview

“…The organic mineral supplements in diet may provide higher Mn bioavailability in poultry species due to the occurrence of antagonists in comparison to the inorganic sources. In poultry, the Mn methionine was reported to be more bioavailable compared to the MnO (Fly et al, 1989;Hilal et al, 2016) or MnSO4 (Henry et al, 1989;Bai et al, 2012). Most organic sources of Mn used are bound to amino acids, which are thought to amplify the bioavailability by reducing complex formations with phytate Ca, P or fiber during the digestion process.…”

“…The Mn metalloenzymes include arginase, phosphoenolpyruvate decarboxylase, glutamine synthetase, as well Mn-superoxide dismutase (Mn-SOD). In particular, MnSOD is significantly expressed in organs including an elevated mitochondria number such as heart, liver and kidneys (Li et al, 2011;Bai et al, 2012;Zhu et al, 2016). Among tissues expressing MnSOD in human (Marklund, 1980), mice (Jones et al, 1995) and chicken (Kong et al, 2003;Zhu et al, 2016), heart has the highest steady state mRNA expression level.…”