Renal ultrastucture changes with experimentally induced microliths in rats

ABSTRACT

This work aimed to study the ultrastructure changes that occur in rat kidney with microlith formation and detecting the feature of formation and mechanism of retention and development of renal tubular crystal deposits. Calcium oxalate stone formation was induced in rats by oral application of stone forming diet containing ammonium oxalate [5.3%] and ammonium chloride [2%] mixed with semisynthetic diet for 6 weeks. Periorbital blood samples were taken for determination of blood urea, serum creatinine, cholesterol and total serum triglycerides at the start of experiment and just before scarification. Plain X-ray was done for three rats at the end of six weeks feeding to detect any abnormal calcification. The rats were anaesthetized and perfusion of kidneys with saline, followed by Karnovsky's fixative. The kidneys were excised and processed for diagnosis by light and electron microscopic [E/M] studies. Microliths were present in kidneys of all rats in this study. Light microscopic study revealed protrusion of apical cells in proximal and distal tubules and presence of cellular debris and crystal ghosts in lumen of proximal and distal convoluted tubules. Transmission E/M study revealed swollen cytoplasm and mitochondria of renal tubular cells. Cellular debris and crystal ghosts were present in lumen of both proximal and distal convoluted tubules. Scanning E/M study revealed that renal tubules appeared swollen and lost their brush borders. Tubules were crowded with red blood corpuscles, cellular debris and crystal nucleations