الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 157 |  |  |
| | | from | 157 | | |
Abstract
The present study was carried out to investigate the host-parasite relationship between male albino rats and different doses of Toxoplasma gondii, the high dose (700 sporulated oocysts / gm body weight) and low dose (200 sporulated oocysts / gm body weight) of this has been done by description of the pathological effects and by carrying out some Haematological, biochemical tests to investigate the changes in serum and liver and to what extent such parasite can affect on the host immune system.
Albino rats weighing 80-90 gm were used in the present study and were classified into three groups:
Group (I): Rats were injected intraperitoneally once at the beginning of experiment with 700 sporulated oocysts/gm b. wt. of the high dose of Toxoplasma sporulated oocysts.
Group (II): Rats were injected intraperitoneally once at the beginning of experiment with 1ml of the low dose of Toxoplasma sporulated oocysts.
Group (III): Rats were injected with an equivalent dose of saline solution (0.9% NaCl) once at the beginning of the experiment and left to be a control group.
Six rats were sacrificed every week from the first and second groups for four weeks also six rats from the control group were sacrificed once at the beginning of the experiment.
The following parameters are studies:
(a) :Haematological Studies:
The changes in the complete blood picture reflected that Toxoplasma gondii caused a sharp decrease in RBCs in both of group I and II, although the observed increase in haemoglobin level compared with non infected control group, and this may be explained as a condition of hypochromic anemia. Changes on the level of WBCs showed a clear increase on the total WBCs in group I and decrease in group II except at 3 rd and 4th weeks, while the differential leucocytes count showed increased number of neutrophils, eosinophil except at 3rd and 4th week and lymphocytes in both infected group
(b) : Biochemical Changes:
Changes in the total protein, lipids and glucose in serum and liver homogenate in all studied groups. Also, the characterization of specific proteins including albumin globulin of α, β and ɤ types.
Biochemical changes showed an increase in the total protein in serum of infected groups. While it was increased in liver tissue in group I, it was decreased markedly in the 2nd group. This increase in total protein was associated with an increase in alpha, beta and gamma globulin in both groups, associated with slight change in albumin serum. The total lipid was significantly increased in serum and liver of rats injected with low and high Toxoplasma dose. Also, glucose level in serum was increased markedly comparing to the non-infected control group along the experimental periods.
(c): Immunological Changes:
Including the innate, Humoral and cellular immunity.
The changes in the immunological response showed a significant increase in complement C3 along the experimental period within group (I &II) and elevated total antibodies in both groups from the 2nd week and up to the end of the experiment. Also IgG was elevated markedly along the experimental period compared to the slight increase in IgM in both groups. Comparing with the non infected group, the infected rats in infected groups showed an increase in the precipitation test.
On the other hand, cellular changes represented in RFC and MIF were affected greatly after Toxoplasma injection, since MIF showed a decrease in both groups up to the 2nd week then it was increased at the 3rd week of injection.
(d)The histopathological changes:
1- The Liver: The present study showed that the Toxoplasma infection leads to necrosis of the infected hepatic cells with increase in the number of inflammatory cells in some areas of the infected liver. Also, there was an increase in the number of Kupffer cells, which is mainly responsible for phagocytosis with vasodilatation of the central vein was observed.
2- The Lung: The examined infected lung revealed that there was a high increase of the inflammatory lymphocyte cells with vasodilatations in the blood vessels surrounding the alveoli. Moreover, the red capsules were increased within these vessels with presence of some inflammatory cells in the infected alveoli.
3- The Intestine: The infected small intestine is greatly affected specially after 3 weeks (H.D) shows complete desquamation and ulceration of the mucosal epithelial with massive number of eosinophils and mononuclear inflammatory cells infiltrated in the connective tissue propria of the villi
4- The kidney: The kidney appeared abnormal in shape and structure after first week (H.D) compact degenerated glomerular tufts appeared with Bowman’s capsule swollen and area of necrosis appeared after 2 weeks (H.D.) and shrinkage of glomerulus.
5- The Brain: The sections revealed that there were small cysts of Toxoplasma in the brain tissue especially after the injection with the high dose. The small cysts were present in aggregations of phagocyte cells of lymphocytes and monocytes The Spleen: The spleen showed an increase in the number of lymphocytes and monocytes. The dilated blood vessels were filled with RBCs. Also, there was thickening in the outer capsule layer.