Abstract:In this study, the histological, immunohistochemical, morphometric, and biochemical changes to pancreatic beta-cells in STZ-induced diabetes were evaluated in rats treated with different doses of caffeine. Fifty adult male Wistar albino rats were divided into five groups: the nondiabetic control group, the diabetic untreated group, and three diabetic groups treated with different doses of caffeine (10, 50, and 100 mg/kg/day). Blood glucose and serum insulin levels were measured. The pancreata were collected and processed into paraffin sections. They were stained using hematoxylin and eosin (H&E) and Masson trichrome stains. The insulin expression in beta-cells was assessed using immunohistochemistry. Morphometrically, the percentage area of anti-insulin antibody reaction, the percentage of beta-cells per total islet cell number, and the average area of the islets were determined. STZ-induced degenerative changes in beta-cells led to decreases in the number of functioning beta-cells and insulin immunoreactivity and to increases in the number of collagen fibers in the islets. In STZ-treated rats, caffeine significantly decreased blood glucose concentration while increasing blood insulin levels at the highest applied dose. It also induced a significant increase in the number of immunoreactive beta-cells. In conclusion, caffeine may have a protective role in the biochemical and microscopic changes in pancreatic beta-cells in diabetes induced in rats through STZ administration.

5-fluorouracil (5-FU) is a potent antineoplastic agent used for the treatment of various malignancies. The L-arginine nitric oxide (NO) pathway involved in the pathogenesis of chemotherapy induced kidney damage. This work investigated the beneficial mechanism of L-arginine supplementation in 5-FU induced nephropathy. Eighty male Wistar rats were divided into four equal groups: control group; L-arginine group (378 mg/rat/day for 4 weeks); 5-FU group (189 mg/rat/week for 4 weeks) and L-arginine for 1 week before and 4 weeks concomitant with 5-FU group. At the end of experiment, the kidney functions were assessed and kidneys specimens were processed for paraffin sections and stained with haematoxylin and eosin (H&E), Masson's trichome (MT) and periodic acid-Schiff (PAS) stains. Other sections were processed for immunohistochemical demonstration of caspase-3 and inducible NO synthase (iNOS). Image analyser was used to analyse the results morphometrically and statistically. L-arginine administration to 5-FU treated animals elicited significant reduction in serum urea and creatinine levels, urine volume, urinary protein excretion and kidney/body weight ratio in comparison to fluorouracil treated group. L-arginine improved glomeruloscelerosis, degeneration of convoluted tubules and interstitial fibrosis in 5-FU treated animals. L-arginine attenuated effectively some biochemical and histological changes in 5-FU nephrotoxicity.

No abstract