Effects of Dietary Iron Deficiency on Muscle Fiber Characteristics and Whole-Body Distribution of Hemoglobin in Mice

Abstract

Effects of dietary iron deficiency on growth, the distribution of hemoglobin (Hb) at rest and during exercise, the characteristics of muscle fiber types, and glycogen depletion patterns were studied in newly weaned male mice. Forty-eight mice were randomly divided into iron-deficient and control diet groups. Severe iron deficiency impaired general growth, but growth was restored following iron repletion. The mean +/- SEM blood Hb concentrations at rest after 7 weeks were 5.8 +/- 0.7 and 12.5 +/- 0.3 g/dl in iron-deficient and control groups, respectively. The mice fed iron-deficient diet for 7 weeks had an increased Hb level of 10.9 +/- 0.5 g/dl 1 week after an i.p. injection of Imferon (1.25 mg Fe). The Hb contents in brain and gastrocnemius as well as whole body were lowered by iron deficiency. Iron-deficient anemic mice tended to increase the percent distribution of Hb to brain during exercise. This value was significantly greater than in control and iron-treated groups. The iron-deficient group had relatively less glycogen than controls, but no significant tendency in glycogen depletion pattern was observed in any fiber types. It is suggested that decreased Hb content in working muscles due, in part, to greater distribution to brain could be one of the limiting factors for work performance in anemic individuals. It is further suggested that decrease in oxidative muscle fibers as well as the decreased concentration and/or activities of oxidative substances may also be one of the limiting factors.

Iron deficiency drives an autosomal dominant hypophosphatemic rickets (ADHR) phenotype in fibroblast growth factor-23 (Fgf23) knock-in mice

“…Similar diets and feeding periods have been used previously to reduce iron status in rodents (16,17). Males and females were analyzed together, because there was no interaction between the primary variables and sex.…”

Nutrition and Sarcopenia—What Do We Know?

“…The effect of iron-deficiency on muscle growth is another poorly studied area. One randomized controlled trial in mice found that severe iron deficiency impaired general muscle growth, but that growth was restored shortly following iron repletion [78]. It is overall unclear how this study translates to humans.…”

Iron deficiency as energetic insult to skeletal muscle in chronic diseases

“…Taking into consideration different extent of reliance on OXPHOS in a distinct type of muscle fibres, it should be noted that major amount of iron is present in slow ‘red’ fibres in which the oxidative energy production prevails. Thus, iron is of particular importance for muscles rich in red fibres, such as dorsal muscles, lower extremity extensors, the diaphragm, and intercostal muscles …”