| CLA(Conjugated Linoleic Acid) is one of the common additives in human food, but the animal experiment shows that its dietary supplementation can cause metabolic obvious disorders, such as fatty liver and hyperglycemia. At the same time, as a kind of unsaturated fatty acid, CLA affects the lipid bilayer of erythrocyte membrane. Studies have shown that, CLA-added diet in aged rats reduces obviously total content of n-6, the unsaturated fatty acid, and decreases the ratio of n-6/n-3 in the membrane of erythrocytes. This CLA-mediated event may result in the inactive alternation of fluidity and osmotic fragility of the membrane so as to the change of hemolysis rate. However, it is not reported whether dietary CLA alters the total number of red blood cells. In this thesis we studied the change of erythrocyte number and its possible reasons in mice with dietary supplementation of CLA, which leaded to metabolic disorders of the animals as reported by the laboratory previously. First of all, male Kunming white mice of 39 day old were fed a diet containing 1.5% of conjugated linoleic acid(group CLA, n=8), 1.5% of linoleic acid as control group(group LA, n=8); CLA group mice appeared metabolism disorders characterized by fatty liver and reduced adipose tissue; Subsequently the detection of of RBC(red blood cell count), HGB(hemoglobin concentration), HCT(hematocrit), MCV(mean corpuscular volume) was performed. The experiment results showed that RBC decreased by 48.96%, HCT by 46.49%, but MCV increased by 7.82% in CLA group mice, compared with that in LA group with the significant differences(p<0.01). HGB in group CLA mice had a decreasing trend(not significant). The data from continuous test indicated that the significant decrease of red blood cells(p<0.05) appeared on day 47, 61, 86 of the feeding in CLA group compared with that in LA group. At the same time, the reticulocyte(Ret) number in blood of CLA group is two times more than that in LA group(p<0.01), implying the compensatory enhancement of hematopoiesis in bone marrow of CLA group; This thesis had a trial to uncover the mechanism of the erythrocyte decrease. We firstly determined the osmotic fragility of red blood cell, the results showed there was no significant differences the two groups(p>0.05). Then, we tested the m RNA level of EPO gene in kidney by Q-PCR and the concentration of Fe in the serum by ferrous benzoxazines colorimetric method, the results both revealed that there was no significant difference. However, the measurement of ELISA kits indicated that VB12 and folic acid in plasma of CLA group were reducedby 24.72%(p<0.05) and 23.15%(p<0.01) respectively, compared with that of LA group. Furthermore, the result of blood routine examination showed that, compared with LA group, the proportion of monocytes(MONO%) of CLA group increased 41.77 times(p<0.05). These results suggested that the reduction of total red blood cells may be attributed to the shortage of the raw material(VB12 and folate deficiency) for the cell synthesis, or strengthened phagocytosis of red blood cells by monocytes, or both. Conclusion: dietary supplementation of conjugated linoleic acid reduced the total number of erythrocytes; the reduction of red blood cells may be resulted from the shortage of VB12 and folate, and/or the increase of monocytes; the increase of reticulocyte number suggested the enhancement of hematopoietic compensatory in bone marrow in CLA group. |
PDF Full Text Request