الفهرس 
Introduction and Aim of the WorkOnly 14 pages are availabe for public view
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Abstract
Diet soda as Diet Coke contains non-nutritive sweeteners (aspartame), which provide the desired sweet taste without the calories. Non-caloric beverages intake has been associated with progression of kidney diseases. Moreover, as they are sweetened with aspartame they might result in central nervous system symptoms like seizures, memory loss, dizziness, headache and behavioral changes.
One of the thousands of chemicals used in our new high-tech foods is the monosodium glutamate (MSG). It is a white crystal-like substance that is used to enhance food taste and flavor. Although many Food and Drug Control Agencies have certified MSG to be safe for human consumption without any specified dosage, experimental findings have linked the intake of MSG with disorders of the central nervous system, a number of neurodegenerative and neurobehavioral changes. In addition, Dietary MSG increased the urinary pH in rats resulted in stone formation and hydronephrosis.
This study was carried out to investigate the effect of Diet Coke and monosodium glutamate salt either separately or in combination on the cerebellum and the kidney of adult male albino rats.
Forty adult male albino rats were used in this study. They were divided into 4 groups.
group I: (included 15 rats) which served as control animals. Rats of this group were subdivided equally into: subgroup IA which kept without treatment, subgroup IB in which each rat received 2.5 ml of distilled water twice daily by oral gavage and subgroup IC in which each rat administrated 0.5 ml of distilled water once daily by oral gavage.
group II (Diet Coke Group): included 10 rats which were subdivided equally into: subgroup IIA in which each rat received 2.5 ml of Diet Coke by oral gavage twice daily and subgroup IIB in which rats received Diet Coke instead of water for drinking throughout the day.
group III (Monosodium glutamate Group): included 5 rats which received 3 gm MSG / kg by oral gavage once daily. Each rat administrated 0.5 ml of MSG salt solution prepared by dissolving the calculated dose of MSG salt in 0.5 ml of distilled water.
group IV (Combination Group): included 10 rats which received combination of MSG and Diet Coke. Rats of this group were subdivided equally into 2 subgroups. Subgroup IVA: in which rats received 3 gm MSG / kg by oral gavage once daily (each rat administrated 0.5 ml of MSG salt solution prepared by dissolving the calculated dose of MSG salt in 0.5 ml of distilled water) and 2.5 ml of Diet Coke twice daily, by oral gavage. Subgroup IVB in which rats received 3 gm MSG / kg by oral gavage once daily (each rat administrated 0.5 ml of MSG salt solution prepared by dissolving the calculated dose of MSG salt in 0.5 ml of distilled water) and Diet Coke ,instead of water, for drinking throughout the day.
At the end of the experiment (21 days), rats were sacrificed by decapitation under general anaesthesia by intraperitoneal thiopental sodium. Then the kidneys and the cerebella of the rats were dissected out.
The left halves of the cerebella were fixed in 10% formalin solution and processed to form paraffin blocks. Paraffin sections were cut at 4-5 µm thickness and subjected to the following:
1- Haematoxylin and eosin stain.
2- Toluidine blue stain.
3- Silver stain (Glees & Marseland Technique).
4- Immunohistochemical stain for glial fibrillary acidic protein (GFAP) to demonstrate the astrocytes.
5- Morphometric and statistical analysis.
The left kidney had been cut into 2 halves, fixed in 10% formalin solution and processed to form paraffin blocks. Paraffin sections were cut at 4-5 µm thickness and subjected to the following:
1- Haematoxylin and eosin stain.
2- Periodic acid Schiff’s reaction (PAS).
3- Modified Masson’s trichrome stain.
4- Morphometric and statistical analysis.
By Light microscopic examination, H&E stained sections of cerebellum showed that sections of group II (Diet Coke group), group III (MSG group) and group IV (combination group) revealed degenerated Purkinje cells which appeared shrunken with dark stained cytoplasm and nuclei. By morphometric analysis there was a significant increase in the mean number of degenerated Purkinje cells in cerebellar sections subgroup IIB, group III and both subgroups of group IV as compared to the control group. Also, there was significant increase in the mean number of degenerated Purkinje cells in subgroup IIB in comparison to subgroup IIA. Moreover, there was significant increase in the mean number of degenerated Purkinje cells in group III as compared to group I and both subgroups of group II. Also, there was significant increase in the mean number of degenerated Purkinje cells in both subgroup IVA and subgroup IVB as compared to all groups and subgroups. Moreover, a significant increase in the mean number of degenerated Purkinje was detected in sections of subgroup IVB in comparison to subgroup IVA.
Toluidine blue stained cerebellar sections showed that the cytoplasm of Purkinje cells of subgroup IIA revealed Nissl’s granules surround the vesicular nuclei. On the other hand, cerebellar sections of subgroup IIB, group III, subgroup IVA and subgroup IVB revealed apparent reduction in the Nissl’s granules content, as compared to the control. Moreover Purkinje cells of both subgroups of group IV showed apparent reduction in their Nissl’s granules content, as compared to all other groups and subgroups.
Glees and Marsland’s silver stained cerebellar sections showed that Purkinje cells in sections of subgroup IIA, subgroup IIB, group III and subgroup IVA revealed darkly stained brown neurofibrils in their cytoplasm. While Purkinje cells of Subgroup IVB showed pale stained brown neurofibrils in their cytoplasm. In sections of subgroup IIA and group III some dendrites appeared from the apical pole of some Purkinje cells to the molecular layer; others lost their dendrites. While Purkinje cells in cerebellar sections of subgroup IIB, subgroup IVA and subgroup IVB lost their dendrites.
GFAP immunostained cerebellar sections revealed a significant increase in the mean number and mean area percentage of positively immunostained astrocytes of subgroup IIA, subgroup IIB, group III and both subgroups of group IV as compared to the control group. Also, there was significant increase in the mean number and the mean area percentage of positive immunostained astrocytes in subgroup IIB in comparison to subgroup IIA. Moreover, there was significant increase in the mean number and mean area percentage of positive immunostained astrocytes in cerebellar sections of group III as compared to control group and both subgroups of group II. In addition, a significant increase in the mean number and mean area percentage of positive immunostained astrocytes was detected in cerebellar sections of both subgroups IVA and subgroup IVB as compared to all groups and subgroups. A significant increase in the mean number and mean area percentage of positive immunostained astrocytes was noticed in sections of subgroup IVB in comparison to subgroup IVA.
Light microscopic examination of kidney sections stained by H&E, revealed focal structural changes in the renal cortex and medulla of group II (Diet Coke group), group III (MSG group) and group IV (Combination group). The renal cortical sections of subgroup IIA showed the least focal structural changes while, sections of subgroup IVB were apparently more affected than all other groups and subgroups. The renal cortex showed pyknotic nuclei of the cells of some PCTs and DCTs while other cells showed vacuolated cytoplasm. Moreover, shrunken glomeruli with widened capsular spaces were noticed in sections of subgroup IIB, group III and both subgroups of group IV. The renal medulla of both subgroups of group II, group III and both subgroups of group IV showed that some cells of the collecting tubules and ducts possessed vacuolated cytoplasm with deeply stained nuclei. Acidophilic debris were detected occupying the lumen of some tubules in sections of subgroup IVA and subgroup IVB. Moreover, renal medullary sections of subgroup IVB showed vascular congestion with extra vascular exudation.
PAS stained renal cortical sections of both subgroups of group II (Diet Coke group), group III (MSG group) and both subgroups of group IV (combination group) showed focal loss of the apical brush borders of some cells of PCTs. The basement membrane of some renal tubules appeared disrupted. Ill-defined areas of PAS positive reaction of the basement membranes of the Malpighian corpuscles were noticed in sections of subgroup IIB, group III and both subgroups of group IV. The renal medulla of both subgroups of group II, group III and both subgroups of group IV showed ill-defined PAS positive reaction of the basement membranes of some of medullary renal tubules.
Masson’s trichrome stained renal sections revealed significant increase in the mean area percentage of collagen fibers of subgroup IIB when compared with group I (control group) and subgroup IIA. In addition, there was significant increase in the mean are percentage of collagen fibers in sections of group III when compared to group I (control group) and both subgroups of group II. Also, significant increase in the mean area percentage of collagen fibers was present in sections of both subgroups of group IV when compared to all other groups and subgroups. Moreover, a significant increase in the mean area percentage of collagen fibers in renal sections of subgroup IVB was observed as compared to all other studied groups and subgroups.