[Effects of different zinc nutritional status on iron metabolism in rats]

To study the effects of different zinc nutritional status on iron metabolism and explore the potential role of iron regulator protein 2 (IRP2) under conditions of zinc deficiency.

Forty clean male SD rats were randomly divided into four groups according to the weight and every group included 10 rats. The rats were administrated normal iron and zinc control group (ZA group), normal iron and slight deficient group (ZD group), Paired fed group (PF group), normal iron and zinc excessive group (ZE group). Rats were sacrificed by sodium pentobarbital anesthesia after 8 weeks and serum, liver and spleen of the rats were collected. The serum zinc, serum iron, hemoglobin, serum transferrin receptor, serum ferritin, iron and zinc in the liver, iron and zinc in the spleen were determined. The level of IRP2 mRNA expression,liver transferring receptor (TfR) mRNA expression and ferritin (Fn) mRNA expression were measured using reverse transcription polymerase chain reaction (RT-PCR) method.

Compared with that of the control group, iron content both in the liver and spleen, and the concentration of serum iron in ZE group was significantly decreased (P < 0.05). Compared with the control group, zinc deficiency increased iron content in the liver and the concentration of serum transferrin receptor significantly (P < 0.05), while the concentration of serum iron was significantly decreased (P < 0.05). Compared with the control group, zinc deficiency increased the level of IRP2 mRNA and TfR mRNA expression in the liver significantly (P < 0.05).

Zinc may affect iron nutritional status by influencing absorption, storage and transportation of iron. Zinc deficiency influences iron homeostasis in cells through affecting the expression of IRP2 and the activity of IRP-RNA combination and then change the expressions of ferritin and transferrin mRNA.