Molecular analysis of increased iron status in moderately exercised rats

Abstract

Although iron plays a critical role in exercise, the regulatory mechanism of iron metabolism remains poorly understood. The aims of the present study were to investigate the effects of different intensity exercise on body iron status and the regulatory mechanism of duodenal iron absorption. Thirty female Sprague-Dawley rats (90-100 g) were randomly divided into three groups: a control group (remained sedentary, CG), a moderately exercised group (swam 1.5 h/day, MG) and a strenuously exercised group (swam with different load, SG). Serum iron status, serum ferritin and Hct were examined after 10 weeks of swimming. Western blot was performed to detect the expression of iron transport proteins: divalent metal transporter1 (DMT1) and ferroportin 1 (FPN1) in duodenal epithelium. The expression of hepcidin mRNA in liver was examined by RT-PCR. The results showed: (1) the body iron status in MG was kept at a high level compared to that of CG and SG, (2) Western blot showed DMT1 with iron responsive element (IRE) and FPN1 in duodenal epithelium which were higher in MG than that of CG and (3) the expression of hepatic hepcidin mRNA was down regulated in MG (p < 0.05). The data suggested that moderate exercise improved iron status and that was likely regulated by increased DMT1 with IRE and FPN1 expression. Hepcidin signaling pathway may involve in the regulation of duodenal iron absorption proteins.

Exploration of the copper-related compensatory response in the Belgrade rat model of genetic iron deficiency

“…In the present investigation, the Dmt1 band, which was much stronger in the b/b rats, was noted at slightly Ͼ55 kDa; other bands on blots were of similar intensity in ϩ/bs and b/bs, likely representing nonspecific signals. A survey of the primary literature reveals a wide discrepancy in the molecular weight of Dmt1 in Western blot analyses, with variations in rodent and human intestine noted from ϳ43 to 85 kDa (34,36,37,57,59). The molecular weight of the Dmt1 detected in the present studies thus falls within ranges reported elsewhere, and its strong induction in the b/b rats lends confidence to it being specific.…”

Effect of melatonin on element distribution in the liver tissue of diabetic rats subjected to forced exercise

“…It was argued that exercise modifi ed distribution of iron in various tissues (25) and also that moderate exercise had a regulatory effect on body iron values (26). The results we found in relation to the iron parameter in our study are congruous with the results of the above-cited researchers.…”

Effects of Exercise Training on Red Blood Cell Production: Implications for Anemia

“…In brief, we agree with Sawka et al [5] and Warburton et al [32] that the above-mentioned discrepancies are likely related to differences in participant sampling, experimental conditions and/or the season in which the research was conducted. For example, 10 weeks of moderate swimming in rats increased iron status, Hb and HCT, while strenuous swimming caused the variables to change in the opposite direction [34]. Initial Hb and HCT levels likely influence training effects on erythropoiesis.…”