Impairment of renal structure and function following heterogeneous chemical mixture exposure in rats.

Renal structural and functional alterations following an exposure to a heterogeneous chemical mixture (HCM) of phthalic acid di butyl ester, 1, 2–dichlorobenzene, cadmium chloride and chromium trioxide, administered through oral gavage in low doses (1/100 and 1/1000 of LD50 value of individual chemical) for 60 days, followed by withdrawal till 120 days resulted in significant rise in kidney lipid peroxidation and fall in the activities of enzymatic antioxidants. However, withdrawal of HCM treatment restored most of these altered parameters. Degenerative changes in the kidney included proximal convoluted tubules devoid of brush boarder with cytoplasmic blebbing, dissolution and sloughing of nuclei. Cortical glomeruli were also affected with epithelial disintegration, pyknosis of podocyte nuclei and mesengial cell hyperplasia. The morphological alterations recovered fully in the low dose compared to the high dose treatment group.

Histochemical and ultrastructural studies on rat proximal convoluted tubules under the effect of 7, 12 dimethylbenz [A] anthracence and tamoxifen treatment

The requirement of ATPase for cellular enzymatic reaction is necessary for understanding how cells are damaged when energy metabolism is impaired in pathologic states. The purpose of this study was to examine the effect of 7, 12-dimnethylbenz/aJanthracene [DMBa] and tamoxifen [TAM] treatment on the activity of A TFase by light and electron microscopy on rat proximal tub miles, also to elucidate the mode of action of TAM in morphological features of apoptosis. 60 male albino rats were included, ten rats were used as control, 20 rats received a single dose of the DMBA only [Sing/100g body weigh and 30 rats received DMBA and treated with TAM [0.2mng/l100g body weight three times weekly] for six months. A marked PAS positive and decreased ATPase activity were shown in destructed brush border and basement in membrane in the group given DMBA, whereas an elevation of ATPase activity was observed after TAM treatment than in DMBA group administration, but it is less than in control. The ultrastructural studies showed marked chromatin condensation with nuclear segmentation as a feature of apoptotic cells after TAM treatment. The depletion of ATPase confirmed the ultrastructural feature of apoptosis. So, we can conclude that TAM may be a protective agent against carcinogenesis. Also, histochemial ATPase technique was found to be a simple method for demonstrating the apoptotic features

Some histological, histochemical and ultrastructural studies on the effect of tobramycin on the convoluted tubules of the kidney of albino rat

Tobramycin is the most active member of all the aminoglycoside antibiotic group acting against gram- negative bacteria. The aim of present study was to detect the effect of tobramycin on tile convoluted tubules in two different dosage regimen. Sixty adult male albino rats were divided into three groups. Group I as control. Group II: included rats which were injected intraperitoneally with daily dose of 4 mg/kg tobramycin in three equally divided doses. Group III: injected with the same previous dose once daily. They were sacrificed after 3,10,14 days of injection and tissue samples from the cortex of each kidney were taken and processed for both light and electron microscopic examination. In group II, by light microscope swelling of the cells lining the convoluted tubules and vacuolation of their cytoplasm as well as brown granules and hemorrhage were observed. The regenerating cells appeared with basophilic cytoplasm. Progressive decrease in succinic dehydrogenase and increase in acid phosphatase enzymatic activities were observed. Ultrastructurally, there were affection of mitochondria and partial or complete loss of microvilli in some tubules were observed. The cytoplasm of some tubules revealed numerous myeloid bodies with various degrees of nuclear degeneration. Dilated basal infoldings and thickened basement membrane was also observed. The previous changes were less evident on administration of the drug in Group III. In conclusion, patients with a previous kidney disease should better avoid the use of this drug whenever possible but if its use is necessary, once daily dosage may be advised for short period

Structure of the Bufo arenarum kidney: renal corpuscle, neck segment and proximal tubule

The structural organization of the renal corpuscle (RC), ciliated neck segment (NS) and the proximal tubule (PT) were studied in the toad, Bufo arenarum, by means of light and transmission electron microscopy. The ciliated neck segment and the proximal tubule are located in the dorsolateral zone of the kidney, while the distal tubules are located in a ventromedial zone. RC are found between these two zones. The glomerular filter apparatus consists of the podocyte epithelium, a basement membrane, a subendothelial space and an endothelium. The podocyte emits cytoplasmatic processes extending over the surface of the glomerular capillaries. These processes divide into further processes ending in expansions known as pediceles. The basement membrane consists of a lamina rara externa and a rather thin lamina densa, while the subendothelial space contains collagen fibers and slender cytoplasmic processes of the mesangial cells. NS are composed of ciliated cells with a characteristic location of the mitochondria. The PT consists of prismatic cells with a dense luminal brush border of long microvilli and numerous apical vesicles. The basal cell membrane is increased by small infoldings. One characteristic structure of the cytoplasm is the presence of lipid droplets. The cytological structure of PT cells can be considered as an adaptation for the reabsorption of organic materials

Studies on the effect of ethanol on the Na+, and the Na+,K+ATPase activities of plasma membranes of rat kidney proximal tubular cells

In the present work it was investigated the effect of 2 percent ethanol on the Na+ and on the Na+, K(+)-ATPase activities. The differential effect of the alcohol on the two ATPases (approximately 40 percent inhibition of the Na(+)-ATPase and approximately 10 percent inhibition of the Na+, K(+)-ATPase), is not due to a higher degree of denaturalization of the enzyme, nor to a faster effect of ethanol on the Na(+)-than on the Na+, K(+)-ATPase. Our results show that ethanol affects the selectivity of the Na+, K(+)-ATPase for Na+ and/or for K+, enhancing the Na+ affinity for the K+ sites, and/or reducing the K+ affinity for its own sites. This effect was not seen for the Na(+)-ATPase, indicating that 2 percent ethanol inhibits the two ATPases in a totally different way

Nephrotoxicity of human Bence Jones protein in rats: proteinuria and enzymuria profile

The effect of intravenous administration of 80 mg purified human Bence Jones protein twice weekly for 5 weeks was investigated in male Wistar rats (N = 7; 2 months old). A state of immunological tolerance was demonstrated by the absence of a B-cell response (plaque-forming cells and hemagglutination titers) and by the absence of detectable antigen or antibody deposition in glomeruli, as indicated by light and electron microscopy. No rise in blood urea level was detected (33.9 +/- 4.3 vs 32.8 +/- 1.3 mg per cent ). There was an increase in proteinuria (5.3 +/- 0.9 vs 32.8 +/- 4.0 mg/day), mainly due to Bence Jones protein excretion (0 vs 29.2 +/- 5.2 mg/day), with a slight but significant increase in albuminuria (0.2 +/- 0.1 vs 1.0 +/- 0.2 mg/day). There was a significant increase of lysosomal N-acetyl-beta-D-glucosaminidase in the urine (6.1 +/- 1.3 vs 72.7 +/- 18.8 mU/mg in creatinine). Lysosomal accumulation of Bence Jones protein in proximal tubular cells was evidenced by immunoelectronmicroscopy with protein A-gold. These results clearly showed proximal tubular dysfunction induced by chronic Bence Jones protein administration, without interference of autologous immune response as demonstrated by immunological state of tolerance

Ultrastructure of convoluted proximal tubule of kidney mice before and after X-ray exposure

Ultrastructural initial changes study of convoluted proximal tubule after single dose of 154.8 mC/Kg (600R), X, ray whole body radiation was performed in 12C57BL mice. Twenty-four hours later, mitochondria evidenced proeminent changes such as cristolyses, dilatation and vacuolization. Within 72 hours, heterochromatin nuclei increased and vanished 144 hours after X-ray exposure. Such findings suggest that recovery probably happened because convoluted proximal tubules take place, regeneration occurs in aslow rate