scholarly journals Dietary iron concentration influences serum concentrations of manganese in rats consuming organic or inorganic sources of manganese

2015 ◽  
Vol 115 (4) ◽  
pp. 585-593 ◽  
Author(s):  
Huaiyong Zhang ◽  
Elizabeth R. Gilbert ◽  
Shuqin Pan ◽  
Keying Zhang ◽  
Xuemei Ding ◽  
...  

AbstractTo determine the effects of dietary Fe concentration on Mn bioavailability in rats fed inorganic or organic Mn sources, fifty-four 22-d-old male rats were randomly assigned and fed a basal diet (2·63 mg Fe/kg) supplemented with 0 (low Fe (L-Fe)), 35 (adequate Fe (A-Fe)) or 175 (high Fe (H-Fe)) mg Fe/kg with 10 mg Mn/kg from MnSO4 or Mn–lysine chelate (MnLys). Tissues were harvested after 21 d of feeding. Serum Mn was greater (P<0·05) in MnLys rats than in MnSO4 rats, and in L-Fe rats than in A-Fe or H-Fe rats. Duodenal divalent metal transporter-1 (DMT1) mRNA was lower (P<0·05) in H-Fe rats than in A-Fe rats for the MnSO4 treatment; however, no significant difference was observed between them for MnLys. Liver DMT1 mRNA abundance was greater (P<0·05) in MnSO4 than in the MnLys group for H-Fe rats. The DMT1 protein in duodenum and liver and ferroportin 1 (FPN1) protein in liver was greater (P<0·05) in the MnSO4 group than in the MnLys group, and in L-Fe rats than in H-Fe rats. Duodenal FPN1 protein was greater (P<0·05) in L-Fe rats than in A-Fe rats for the MnLys treatment, but it was not different between them for the MnSO4 treatment. Results suggest that MnLys increased serum Mn concentration as compared with MnSO4 in rats irrespective of dietary Fe concentration, which was not because of the difference in DMT1 and FPN1 expression in the intestine and liver.

2001 ◽  
Vol 120 (6) ◽  
pp. 1412-1419 ◽  
Author(s):  
Heinz Zoller ◽  
Günter Weiss ◽  
Igor Theurl ◽  
Robert O. Koch ◽  
Wolfgang Vogel ◽  
...  

2000 ◽  
Vol 278 (6) ◽  
pp. G930-G936 ◽  
Author(s):  
Phillip S. Oates ◽  
Carla Thomas ◽  
Elizabeth Freitas ◽  
Matthew J. Callow ◽  
Evan H. Morgan

Regulation of iron absorption is thought to be mediated by the amount of iron taken up by duodenal crypt cells via the transferrin receptor (TfR)-transferrin cycle and the activity of the divalent metal transporter (DMT1), although DMT1 cannot be detected morphologically in crypt cells. We investigated the uptake of transferrin-bound iron by duodenal enterocytes in Wistar rats fed different levels of iron and Belgrade (b/b) rats in which iron uptake by the transferrin cycle is defective because of a mutation in DMT1. We showed that DMT1 in our colony of b/b rats contains the G185R mutation, which in enterocytes results in reduced cellular iron content and increased DMT1 gene expression similar to levels in iron deficiency of normal rats. In all groups the uptake of transferrin-bound iron by crypt cells was directly proportional to plasma iron concentration, being highest in iron-loaded Wistar rats and b/b rats. We conclude that the uptake of transferrin-bound iron by developing enterocytes is largely independent of DMT1.


2015 ◽  
Vol 122 (4) ◽  
pp. 908-920 ◽  
Author(s):  
Rui-Chen Shu ◽  
Lin-Lin Zhang ◽  
Chun-Yan Wang ◽  
Nan Li ◽  
Hai-Yun Wang ◽  
...  

Abstract Background: Hyperalgesia is one of the negative consequences following intraoperative analgesia with remifentanil. Peroxynitrite is a critical determinant in nociceptive process. Peroxynitrite inactivates iron-sulfur cluster that results in mitochondrial dysfunction and the release of iron, leading to mitochondrial iron accumulation. Iron accumulation mediated by divalent metal transporter 1 (DMT1) plays a key role in N-methyl-d-aspartate neurotoxicity. This study aims to determine whether peroxynitrite contributes to remifentanil-induced postoperative hyperalgesia via DMT1-mediated iron accumulation. Methods: Behavior testing was performed in rat model at different time points. Three-nitrotyrosine, nitrated manganese superoxide dismutase, and DMT1 with/without iron-responsive element [DMT1(+)IRE and DMT1(-)IRE] in spinal cord were detected by Western blot and immunohistochemistry. Spinal iron concentration was measured using the Perl stain and atomic absorption spectrophotometer. Hydrogen-rich saline imparting selectivity for peroxynitrite decomposition and iron chelator was applied in mechanistic study on the roles of peroxynitrite and iron, as well as the prevention of hyperalgesia. Results: Remifentanil induced thermal and mechanical hyperalgesia at postoperative 48 h. Compared with control, there were higher levels of 3-nitrotyrosine (mean ± SD, hyperalgesia vs. control, 1.22 ± 0.18 vs. 0.25 ± 0.05, n = 4), nitrated manganese superoxide dismutase (1.01 ± 0.1 vs. 0.19 ± 0.03, n = 4), DMT1(-)IRE (1.42 ± 0.19 vs. 0.33 ± 0.06, n = 4), and iron concentration (12.87 ± 1.14 vs. 5.26 ± 0.61 μg/g, n = 6) in remifentanil-induced postoperative hyperalgesia, while DMT1(+)IRE was unaffected. Eliminating peroxynitrite with hydrogen-rich saline protected against hyperalgesia and attenuated DMT1(-)IRE overexpression and iron accumulation. Iron chelator prevented hyperalgesia in a dose-dependent manner. Conclusions: Our study identifies that spinal peroxynitrite activates DMT1(-)IRE, leading to abnormal iron accumulation in remifentanil-induced postoperative hyperalgesia, while providing the rationale for the development of molecular hydrogen and “iron-targeted” therapies.


2016 ◽  
Vol 291 (33) ◽  
pp. 17303-17318 ◽  
Author(s):  
Izumi Yanatori ◽  
Des R. Richardson ◽  
Kiyoshi Imada ◽  
Fumio Kishi

Ferroportin 1 (FPN1) is an iron export protein found in mammals. FPN1 is important for the export of iron across the basolateral membrane of absorptive enterocytes and across the plasma membrane of macrophages. The expression of FPN1 is regulated by hepcidin, which binds to FPN1 and then induces its degradation. Previously, we demonstrated that divalent metal transporter 1 (DMT1) interacts with the intracellular iron chaperone protein poly(rC)-binding protein 2 (PCBP2). Subsequently, PCBP2 receives iron from DMT1 and then disengages from the transporter. In this study, we investigated the function of PCBP2 in iron export. Mammalian genomes encode four PCBPs (i.e. PCBP1–4). Here, for the first time, we demonstrated using both yeast and mammalian cells that PCBP2, but not PCBP1, PCBP3, or PCBP4, binds with FPN1. Importantly, iron-loaded, but not iron-depleted, PCBP2 interacts with FPN1. The PCBP2-binding domain of FPN1 was identified in its C-terminal cytoplasmic region. The silencing of PCBP2 expression suppressed FPN1-dependent iron export from cells. These results suggest that FPN1 exports iron received from the iron chaperone PCBP2. Therefore, it was found that PCBP2 modulates cellular iron export, which is an important physiological process.


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