الفهرس 
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Abstract
In the present study 173 specimens of C. gariepinus were used to determine the adverse effect of sublethel concentrations of diazinon (1.1 and 3.3 mgL-1) on behavioral changes, mortality, blood constituents (Erythrocyte count, hemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, total leukocyte count with differential count, total protein, cholesterol, Triglyceride, glucose, Urea, creatinin, ALT, AST, ALP, Lipid Peroxidation and DNA fragmentation of C. gariepinus. Also, histopathological characteristics of the liver, kidney, gills and testis were studied. The validity of VC (50mg/kg body weight) and VE (100mg/kg body weight) for inhibition of such effects was testified. The results can be summarized in the following points: LC50 Determination Estimation of diazinon LC50 showed that LC50 values of diazinon were 17.4, 14.23, 12.33 and 11.76 mg L-1 at 24, 48, 72 and
96 hrs respectively. Behavioral, mortality and morphological changes After 14 and 28 days of treatment, diazinon-exposed fish showed abnormal behavior such as restlessness, sudden quick movements, air gulping, swimming on the back. Fishes treated with VC and VE and their combinations were in better conditions. Blood constituents
A- Hematological parameters
The main effect of diazinon was significantly decreased in the two periods for red-blood-cells (RBCs) count, haemoglobin (Hb) content and haematocrit (Hct) value of C. gariepinus. Vitamin C main effect was significant in both periods except for RBCs. VE main effect was significant only at the second period for RBCs, Hb and Hct. VC-VE interaction effect was highly significant in both periods. Diazinon-VC-VE interaction was only significant in the second period. Diazinon main effect was highly significant (P<0.05) in all periods for MCV, MCH and MCHC. VC main effect was significant for the three previous parameters in all periods. VE and its interaction with diazinon were also significant in all exposure periods for MCV, MCH and MCHC. VC-VE interaction effect was significant for MCV, MCH and MCHC. Diazinon-VC-VE interaction showed a significant effect for the three parameters. VC-VE- period of exposure interaction effect was significant only for MCH. Diazinon main effect was highly significant (P<0.05) in all exposure periods for WBC, GRAN, LYM and MONO. VC main effect was significant in all exposure periods for the four previous parameters.
VE main effect was significant in all exposure periods for WBC, GRAN, LYM and MONO. Diazinon-VC-VE interaction was not significant in GRAN. The period of exposure main effect was highly significant for the four previous parameters. VC-VE Period of exposure interaction effect was not significant in GRAN and LYM. Diazinon main effect was highly significant (P<0.05) in all exposure periods for erythrocytes alteration. VC and VE main effect was significant in all exposure periods for both of them. VE and its interactions main effect were significant in all exposure periods for the previous parameters. The period of exposure main effect was significant in erythrocytes alteration. Exposure of C. gariepinus to sublethal concentrations of diazinon (1.1 and 3.3 mgL-1), 50 mg/kg body weight of VC and 100
mg/kg body weight of VE resulted in morphological changes in the red
blood cells and appearance of some pathologic types of cells. The major
alterations of RBC’s are damage of cell membrane with pale cytoplasm,
cells have prominent vacuoles, nuclei lose some of their central dye (A
sign of karyolysis, also crenated cells, echinocytes, tear DROP like cells,
acanthocyte, sickle cells, Swelled cells, pale cytoplasm, lysis of some red
cells and some cells appear to be stacked together).
B- Biochemical parameters Kidney functions Diazinon main effect was highly significant (P<0.05) in all periods for both of Urea and Creatinine. VC main effect was significant for the two previous parameters. VE main effect was only significant for Creatinine in all exposure periods. VC-VE interaction effect was significant for Urea only. Diazinon-VC-VE interaction effect was not significant for the two parameters. VC-VE period of exposure interaction effect was not significant for Urea and Creatinine. Liver functions
Diazinon main effect was highly significant (P<0.05) in all exposure periods for TP, Alb, Glo and ALB/GLOB ratio. vitamin C main effect was significant in all exposure periods for the four previous parameters. Vitamin E main effect was significant in all exposure periods for TP, Alb, Glo and ALB/GLOB. VC-VE interaction effect was not significant only for TP in all exposure periods. Diazinon-VC-VE interaction effect was significant in all exposure periods for the previous parameters. Glucose and Lipogram Diazinon reflected highly significant effects in Glu, CHO, TRI, HDL and LDL (P<0.05) in the two periods of exposure. Vitamin C main
effect was significant for all parameters in all exposure periods. Vitamin E main effect was significant in all exposure periods for Glu, CHO, TRI, HDL and LDL. VC-VE interaction effect was highly significant in all
exposure periods (P<0.05) for the previous parameters. VE-Periods interactions were not significant for HDL in all exposure periods. Diazinon-VC-Period interaction effect was significant in all parameters except CHO and HDL in all exposure periods. Lipid peroxidation (LPO) and DNA fragmentation The levels of Lipid Peroxidation and DNA fragmentation in liver increased during the two periods of exposure of Diazinon. Such levels decreased with addition of VC and VE and their combinations. Histopathological observations
A-Transmission Electron Microscope (TEM) Liver: TEM examination of the liver revealed the following changes in treated fish (3.3 mgL-1 diazinon) as compared to control.The liver of fish showed transformation of the rough endoplasmic reticulum into concentric arrays, proliferation of smooth endoplasmic reticulum, degeneration of mitochondria cristae, lipid accumulation and wide orcas of rarefied cytoplasm. Many ultrastructural alterations were observed in fish exposed to diazinon (3.3 mgL-1 diazinon) plus vitamin C (50 mg/kg of the fish weight): Some mitochondria and rough endoplasmic reticulum restored their normal appearance. Major alteration was observed like numerous lipid droplets of varying sizes observed in the cytoplasm. The ultrastructaral changes in the liver of Fish exposed to diazinon (3.3 mgL-1 diazinon) plus Vitamin E (100 mg/Kg of the fish weight) are: Mitochondria retained their original structure and rough
endoplasmic reticulum was arranged parallel or concentric cisternae. Increased number and sizes of lipid droplets in the hepatocytes. The ultrastructaral changes in the liver of Fish exposed to diazinon (3.3 mgL-1 diazinon) plus vitamin C (50 mg/kg of the fish weight) and Vitamin E (100 mg/Kg of the fish weight) are: The rough endoplasmic reticulum was arranged in parallel cisternae around the nucleus. Beside, proliferation of smooth endoplasmic reticulum was encountered in the cytoplasm and increased sizes of lipid droplets.
C- Light microscope
1- kidney: Treatment with (1.1 and 3.3 mgL-1) diazinon for 14 and 28 days
showed histopathological changes. Hydropic degeneration and necrosis of some renal tubules were
observed. Examination of kidney sections of vitamin C (50 mg/kg of the fish weight) and/or vitamin E (100 mg/kg of the fish weight) administered fish in the two periods showed: Some renal tubules were improved in structure, but other ones were still having some vacuolation. Also, some Malpighian corpuscles still suffering from distinct features of degeneration.
2- Gills:
Treatment with (1.1 and 3.3 mgL-1) diazinon for 14 and 28 days showed histopathological changes.
The main histological changes of the gills included hyperplasia of epithelium, rupture of the secondary lamellae and degeneration of the chondrocytes of the gill cartilage. Examination of gills sections of vitamin C (50 mg/kg of the fish weight) and/or vitamin E (100 mg/kg of the fish weight) administered fish in the two periods showed: Vacuolatin and hyperplasia in primary lamellae. Some secondary lamellae have restored their normal appearance.
3- Testis:
Treatment with (1.1 and 3.3 mgL-1) diazinon for 14 and 28 days showed histopathological changes. Major alterations were observed in testis such as loosening of tissue, degeneration of spermatogenia of spermatocytes, empty seminiferous tubules and rupture of tubular wall. Examination of testis sections of vitamin C (50 mg/kg of the fish weight) and/or vitamin E (100 mg/kg of the fish weight)
administered fish in the two periods showed good: Some seminiferous tubules were improved in structure, but other ones were still having some alterations of tissue . The treatment with the antioxidants (VC and VE) revealed less disintegration of
tissue.