ABSTRACT

Bone marrow responses of albino rats in experimentally induced sub-acute blood loss and haemolytic anaemia were studied. Thirty albino rats of both sexes between the ages of 10-12 weeks were used for the study. The rats were assigned at random into three groups of ten each (5 males and 5 females) labelled A - C. Baseline values of the haematological parameters were determined using standard procedures before the commencement of the study. Rats in group A were not induced with anaemia and served as control. Sub-acute blood loss anaemia was induced in group B using the retro-orbital bleeding technique and haemolytic anaemia in group C using phenyl-hydrazine. At the end of the specified period of induction of anaemia for each group, the haematological parameters were re-assessed. After anaemias were established, the rats were humanely sacrifice and the femur was harvested for bone marrow cytology. The differential bone marrow counts were evaluated using standard procedures. Data generated from all parameters for each of the groups were compared using a one way analysis of variance, and variant means were separated using the least significant difference. Results obtained pre and post anaemia were subjected to T-test for paired samples. Significant difference was accepted at P < 0.05. The PCV, HBC and RBC counts of the rats in groups B and C decreased significantly (p < 0.05) after anaemia was successfully induced. The type of anaemia produced in group B, was a macrocytic hypochromic anaemia which was not significant. However, in group C, a macrocytic hyperchromic anaemia was produced due to haemoglobinaemia. The differential femoral bone marrow counts of the rats showed significant decrease of the erythroblasts in the haemolytic group when compared with the control. The late normoblasts of the sub-acute blood loss anaemia and haemolytic anaemia were significantly increased. However, all the other cells of the erythrocytic series were present but did not vary significantly. The greatest percentage increase in the erythrocytic series was recorded for haemolytic anaemia (65.02%) followed by sub-acute blood loss anaemia (58.82%) and for the control (50.50%). The myeloid cells were 48.85% (control), 38.57% (sub-acute blood loss anaemia) and 34.02% (haemolytic anaemia). The myeloid erythroid ratio was 0.97: 1, 0.66: 1 and 0.52: 1 in the control, haemolytic, and sub-acute blood loss anaemia respectively. Other cells which were counted did not vary significantly except for the haematogone which increased significantly in the haemolytic group. Based on the findings of the study, haemolytic anaemia had better bone marrow regeneration than the sub-acute blood loss anaemia group.