histological study on the early postnatal development of the pancreas of albino rat

Thirty albino rats at various ages were used to study the early postnatal development of the pancreas. They were sacrificed using either inhalation in groups at the ages of 1, 3, 7, 15, 21 and 30 days of postnatal life. Each group consisted of 5 animals, one was derived from each of the five mothers. The part of the pancreas closed to the spleen in each animal was dissected and fixed in 10% formol saline. The specimens were h and led properly to prepare 7 mum-thick paraffin sections which were subjected to the following techniques: 1] Hematoxylin and eosin, 2] Mallory stain, 3] Modified aldehyde fachsin stain to demonstrate the B-cells of the pancreatic islets, 4] Wilder's silver technique for the demonstration of the reticular fibers. Results were given in details

Evaluation of the effect of bezafibrate on the liver of albino rats fed by fatty diet

Twenty five male albino rats of 150-200 gm B.W. were used in this study, trying to detect the histological effects of feeding with high caloric fatty diets on the liver, and to evaluate the usage of bezafibrate [as an antihyperlipidemic drug] on the livers of animals bred on such fatty diets. Five animals served as a control group where they were bred all over the experiment on a standard balanced diet. Twenty rats were bred for 7 weeks on a high caloric fatty diet formed of cream extra-added to full cream milk and bread. After 4 weeks of feeding with the prepared fatty diet, the hepatocytes of the rats bred on such a diet appeared overloaded with PAS +ve glycogen granules resulting in the ballooning and vacuolation of these cells, specially in the periphery of the hepatic lobules. This might be due to the increased blood level of the glycerol fraction of the absorbed fat which was handled and utilized in the same way as carbohydrates. One week treatment of the rats, receiving a high fatty diet, with bezafibrate resulted in the marked depletion of the hepatocytes from their cytoplasmic content of the PAS +ve glycogen granules with no vacuolation. After 2 and 3 weeks of treatment of the fed animals with bezafibrate, a progressive moderate revacuolation and reappearance of glycogen was observed. The effect of the drug and the noticed hepatocytic changes might be related to the changes of the blood glucose level caused by it, and mentioned by some authors

Senile changes of the renal cortex [an E/M study]

In order to clarify the ultrastructural changes in the kidney due to senility, 14 adult male albino rats were used, where they were divided into two groups. The first group consisted of 8 senile rats aged 1 - 1.5 years, whereas the other 6 animals were aged 5 - 6 months and served as a comparative second group. The renal corpuscles of the senile rats exhibited an irregularity both in thickness and arrangement of the feet processes of their podocytes, where they appeared attenuated in some sites and fused together elsewhere. The glomerular basement membrane was thickened, mainly due to the widening of its lamina densa. These glomerular changes might be an indication to the affection of the filtration capacity of the senile kidneys. The senile renal tubular epithelial cells were characterized by their smaller, more electron dense mitochondria, irregularity and increased thickness of their basement membranes. These characters might explain the decreased reabsorptive and secretory functions of the renal tubules described by many authors. The senile proximal convoluted tubules showed an increased number of both in the pinocytotic vesicles and lysosomes which might be related to the possible increased rate of passage of the protein macromolecules through the senile leaky glomerular filtration barrier. The cortical interstitium of the senile kidneys contained hyperactive fibroblasts, which might indicate the early interstitial renal fibrosis. The basement membrane of the endothelium of the small cortical vessels was thickened and lost its elastic tissue content. This could be a sign of early atherosclerotic changes that might be the trigger for the later rise of blood pressure in old age

histological changes in the liver of albino neonate rats born to orally hyperglycaemic mothers

This work demonstrated that at birth the offsprings of the hyperglycemic mothers were hyperglycemic too, and this neonatal hyperglycemia gradually declined to reach the normal level by the age of four weeks. This might prove the initial impairment of the function of the exhausted beta cells of the pancreatic islets in these hyperglycemic offsprings and their gradual recovery. On the other hand, the hepatocytes of the rats born to hyperglycemic mothers were markedly affected all over the lobules. At birth, they were enlarged and they showed fatty changes which could be attributed to the fetal hyperglycemic and hyperinsulinemic state induced by the maternal hyperglycemia. No other microscopic changes could be detected. This work also proved that these fetal hepatic fatty changes, due to maternal hyperglycemia were not permanent, where slow recovery of the organ was observed and it was nearly complete by the age of four weeks