الفهرس | Only 14 pages are availabe for public view |
Abstract The present study was planned to investigate the effect of iron deficiency and iron-load on brain function. Our study included animal and human studies. (I) The animal study: Sixty three male weanling albino rats Sprague-Dawely strain of mean body weights 70 ± 10 g were used. The rats were randomly assigned to seven experimental groups. Groups (1 and 2): normal rats which were fed on a control (CN) diet (35mg Fe/Kg diet) for 21 and 28 days, respectively; groups (3 and 4): iron-deficient rats which were fed on an iron-deficient (ID) diet (3mg Fe/ Kg diet) for 21 and 28 days, respectively; group (5): iron-repletion rats which were fed on an irondeficient diet for three weeks followed by an iron-adequate diet for one week; groups (6 and 7): iron load rats which were fed on an iron-load (IL) diet (250 mg Fe/ Kg diet) for 21 and 28 days, respectively. Hematological variables (hemoglobin, hematocrit and red blood cells count) were estimated in whole blood, as well as blood indices: mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC) were calculated. Serum and brain iron, TIBC, ferritin, transferrin and transferrin saturation were estimated as well as dopamine and serotonin concentration in the brains of different groups. 1- Iron deficient diets for 21 days caused significant decrease in hemoglobin concentration and hematocrit by -12.69% and -13.30%, respectively and non-significant decrease in red blood cells count, as compared to control normal rats for 21 days. The hemoglobin concentration, hematocrit and red blood cells count increased significantly in the iron-repleted group (Repl.) as compared to the normal animals (CN, 28 days) or that stayed on iron deficient diets for 28 days (ID, 28 days). 2- Iron-load rats (28 days) showed non-significant change in hemoglobin, hematocrit and red blood cells count as compared to control normal group (28 days). 3- The values of MCH and MCV of rats fed on iron deficient diets for 28 days were significantly lower by -13.95% and -14.03%, respectively than control normal values recorded at 28 days. Whereas, the MCHC level was not significantly affected following iron deficiency for 28 days from the control groups (CN, 21 and 28 days) and iron-deficient group for 21 days. 4- The present results demonstrate that, iron repletion for one week (Repl.) non-significantly elevated MCH and MCV and non-significantly reduced MCHC as compared with iron-deficient group (ID, 28 days). 5- MCV was markedly elevated in iron-load fed rats (for 21 and 28 days) as compared to control normal groups (for 21 and 28 days). 6- Iron deficiency for both 21 and 28 days showed significant decrease in serum iron and ferritin and increase in TIBC as compared with control groups (CN, 21and 28 days). Whereas, iron-load group showed opposite results. 7- Consuming iron adequate diets for one week after three weeks of iron deficiency, induced significant elevation in the level of serum iron and ferritin and decrease in TIBC as compared with their base line levels in irondeficient rats for 28 days (ID, 28 days). 8- When diets contain low iron (3 mg Fe/ Kg diet) were ingested either for 21 or 28 days, the serum transferrin, and the % of transferrin saturation were significantly increased and decreased, respectively than did the corresponding diets adequate in iron for 21 and 28 days. Diets contain high iron (250 mg Fe/ Kg diet) showed opposite results. For the iron-repleted rats for one week, the serum transferrin and the % of transferrin saturation were significantly decreased and increased, respectively as compared to iron-deficient animals (21 and 28 days). 9- Iron-deficient diet-fed rats for 28 days showed significant decrease in the brain iron and ferritin concentration by -71.80% and -12.33%, respectively as compared with control normal rats (CN, 28 days). Brain iron and ferritin levels were markedly elevated in ironload rats (28 days) by 73.37% and 34.77%, respectively as compared to control normal rats (28 days). 10- TIBC significantly increased in iron-deficient groups (ID, 21 and 28 days) and significantly decreased in ironload groups (IL, 21 and 28 days) as compared with the control groups (CN, 21 and 28 days). 11- The brain iron, and ferritin in repleted rats (G5) were greater than in iron-deficient rats (ID, 28 days), but were still lower than control normal (CN, 28 days) by -48.44% and -6.23 %, respectively. 12- All rats fed with iron-deficient diets for 21 and 28 days showed significant increase in the level of brain transferrin, while rats fed with iron-load diets for 21 and 28 days showed significant decrease as compared with control groups (21 and 28 days). 13- Consuming iron-deficient diets and iron-load diets (either for 21 and 28 days) induced significant decrease and increase on the % of transferrin saturation, respectively as compared to control normal diets (either for 21 and 28 days). 14- Repletion for one week in iron-deficient rats resulted in significant decrease in brain transferrin and significant increase in % of transferrin saturation as compared to those maintained on the iron-deficient diets (ID, 28 days). 15- All rats which were fed iron-deficient diets for 21 and 28 days exhibited a decrease in the level of brain serotonin as compared with those of control groups (CN, 21 and 28 days), while the brain dopamine significantly decreased in iron-deficient group (ID, 28 days) as compared with the control normal group (CN, 28 days). 16- The levels of brain serotonin showed significant increase for iron-load group (IL, 28 days) by 7.70% but non-significant increase for iron-load group (IL, 21 days) as compared with their control groups (CN, 28 and 21 days), respectively. The levels of dopamine in the brain of rats which were fed on iron-load diets either for 21 and 28 days had almost the same results as that in control normal rats (CN, 21 and 28 days). 17- Significant elevations in the values of brain serotonin and dopamine were noticed in the iron-repleted rats as compared with iron-deficient rats (ID, 28 days). 18- The current study revealed that, the levels of serum iron showed significant positive correlation with serum ferritin, brain iron and brain serotonin. However, it showed significant negative correlation with serum transferrin in different groups studied. Investigations have also shown that, brain iron recorded positive correlation with brain ferritin and with brain serotonin and negative correlation with brain transferrin among different experimental groups. The current study also presented that, there is no positive or negative correlation between brain dopamine and both serum iron and brain iron among different experimental groups. (II) Human study: The present study was performed on a total number of twenty seven Egyptian male children with an age range of 7-15 years, the chosen cases included three groups. Group 1, Control (Hb ranged from 11 to 12.8 g/dl); group 2, irondeficient (Hb ranged from 8 to 9.5 g/dl) and group 3, ironoverload (Hb ranged from 6 to 8 g/dl). 1- The results showed that there is significant decrease in hemoglobin concentration in iron-deficient group and iron-overload group by -25.38% and -40.45%, respectively as compared to the control normal group. The levels of hematocrit were decreased significantly by -31.23% and -41.22% in iron-deficient and ironoverload groups, respectively as compared to the control group. 2- A significant decrease in red blood cells count was observed in iron-deficient group and iron-overload group by -36.98% and -40.48% as compared to the control group. 3- The results showed that the values of MCH, MCV and MCHC were increased in iron-deficient group by 18.16%, 9.25% and 7.81%, respectively as compared to the control group. However, it was found that ironoverload group did not exhibit the same trend. 4- Results illustrated that the serum iron and ferritin concentrations decreased by -43.43% and -3.29% respectively in iron-deficient group and increased by 90.56% and 2556.63%, respectively in iron-overload group as compared to the control group. On the other hand, the values of total iron binding capacity showed significant increase in iron-deficient group by 40.57% and significant decrease in iron-overload group by -15.25% as compared to the control group. 5- Serum transferrin values increased in iron-deficient group by 40.58% but decreased in iron-overload group by -15.25% as compared to the control group. On the other hand, the values of the percentage of transferrin saturation decreased in iron-deficient group by -59.64% and increased in iron-overload group by 125.01% as compared to the control group. 6- The serum serotonin and dopamine concentration were decreased by -37.84% and -38.20%, respectively in iron-deficient group, while increased by 482.91% and 32.83%, respectively in iron-overload group as compared to the control normal group. 7- There was significant positive correlation between serum iron concentration and serum ferritin concentration, serum serotonin concentration, serum dopamine concentration, respectively among human groups. On the other hand, serum iron concentration showed significant negative correlation with serum transferrin concentration, among different human groups. |