Study of Effect of Methomyl on Some Hematological , Biochemical Parameters and Histological Changes in Male Albino Rats

This study has been designed to study the effect of methomyl on hemodynamic, liver and kidney in rats. Methomyl compound (0.5, 1, and 2 mg/kg. bw) was orally administered once per a day during a period of 28 days of experiment. Results showed a significant(P<0.05) decrease in the level of WBC, HCT, MCHC and a non-significant decrease in the level of RBC, HB, MCV, MCH, was observed in the methomyl group, while the level of PLT significantly increased in Methomyl group in comparison with control group. Non-significant decrease in a level of serum urea in all three groups of Methomyl, while serum creatinine level deceased non-significantly in group1 and group 2, but increased non-significantly in group3 of Methomyl when compared with control group. A Significant decrease in the level of HDL, with significant increase in the level of serum cholesterol, ALT and AST. A non-significant increase in the level of TG, LDL, VLDL and ALP of methomyl group when compared with control group. The Histology of liver of rat treated with 0.5,1 and 2, mg / kg bw. methomyl showed that dilation of central vein, sinusoids between hypertrophied hepatocytes and cytoplasmic vacuolization with loss of radial arrangement of cells, Meanwhile, kidney showed some changes including glomerular degeneration, tubular degeneration, hemorrhage, infiltration and glomerular shrinkage.


Experimental Design
The rats were divided into four groups, each with six animals and continued for 28 days as follows: Group 1: Control.The rats were given standard rat chow and ad libitum and 0.5 ml of saline orally.
Group 2: The rats were given standard rat chow with Methomyl by oral gavage (0.5 mg/kg bw) daily Group 3: The rats were supplied with standard rat chow with Methomyl by oral gavage (1 mg/kg bw) daily Group 4: The rats were supplied with standard rat chow with Methomyl by oral gavage (2 mg/kg bw) daily

Body and Organs Weight
Initial and final body weights were recorded for the calculation of body weight gain, rats were dissected and the liver and kidney weight were determined by using sensitive balance.

Blood Sampling
ketamine hydrochloride (100mg/ kg bw) used and 5ml of blood samples drawn from the heart puncture for each rat in each group, 2ml of blood collected into heparinized tubes for determination of some hematological parameters such as white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (Hb) concentration, hematocrite (HCT) level, red blood

Histological Examination
The kidney and liver were removed and fixed in 10% neutral buffered formalin solution, after preparation the sections were stained with hematoxylin and eosin (13) and examined using a light microscope.

Statistical Analysis
Data were expressed as mean ± standard error (SE), and were analyzed using Statistical Package for Social Science (SPSS/ Version 20) software.Significance between experimental groups was determined using one way analysis of variance (ANOVA) followed by least significant difference (LSD) test for comparison between two groups.P values less than 0.05 were considered statistically significant.

Table (1): Effect of Methomyl on Some Hematological Parameters in Male Rats and Control
Group after 28 days.

Table (3): Effect of Methomyl on Body Weight gain of The Male Rats after 28 Days.
Table (4) show the effects of methomyl administration for 28 days on organs weight (liver and kidney), weight of liver increased significantly in all three groups (11.498±0.112,13.370±0.317and 13.615±0.722)in G1, G2 and G3 respectively as compared to control group

Histopathological Changes In Liver And Kidney
Normal liver structure appeared in the form of hepatic lobules in which there were centrally located central veins, which were surrounded by hepatocytes arranged in the form of hepatic cords separated from each other by hepatic sinusoids (Fig. 1A).The liver of rats treated with methomyl at dose level 0.5 mg/kg bw, after 28 days of treatment was normal as control (Fig. 1B).However, the liver of rats treated with methomyl at dose level 1 and 2 mg/kg bw, after 28 days of treatment showed degenerative changes in the liver including dilation of central vein, congestion blood vessels, infiltration and vasodilatation (Fig. 1C and 1D).In normal histologic structure of the kidney, the cortex contains glomerular tufts scattered in between proximal and distal convoluted tubules (Fig. 2A).Kidney of rats treated with Methomyl at dose level 0.5 mg/kg bw, after 28 days of treatment showed no changes (Fig. 2B).However, for rats treated with Methomyl at dose 1 and 2 mg/kg bw, after 28 days of treatment caused destruction of the normal pattern of the renal tissue.These damages were encountered by the presence of shrinkage of glomerular tuft, thickening of parietal layer of Bowman's capsule, glomerular degeneration as well as cellular infiltration is clearly seen and renal medulla showed dilated collecting tubules stuffed with R.B.Cs.(Fig. 2 C, D and E).examination results in this study demonstrated that 28 day the oral intake exposure of rat to methomyl at the tested dose 1and 2 mg/kg bw.resulted in degenerative changes in the liver including congestion blood vessels, infiltration ,vasodilatation and hemorrhage.The liver recognized as a target organ of the toxic impact regarding its function in biotransformation and excretion of xenobiotic (20).These present results are in agreement with (21) who reported similar histopathological changes including mononuclear cell infiltration, congestion, hydropic degeneration and hepatocellular damage in the liver of male rats treated with dimethoate, endosulfan and carbaryl.Also (22) who found that a 30-day exposure of male rats to dimethoate

Table ( 2): Effect of Methomyl on the Lipid Profile in Male Rats and Control Group after 28 days. Group Control G1 (0.5 mg
/kg bw)G2(1 mg/kg bw)G3(2 mg/kg bw) P