The Effects of Aqueous Extract of Coffee on the Mean of Glomerular Volume in Male Rat

Coffee is a diuretic plant, cause vascular expansion and reduce free radical oxygen. There is evidence that show its effects on kidney. Low dose of coffee reduces blood urea and cratinine but its overdose may lead to glomeruloschelrosis. In this study, the effect of high dose of coffee on rat kidney was evaluated by stereological method.

In an experimental study, 48 Sprgue-Dawley rats 230-250 gr were selected and divided randomly into 4 groups. The control group was fed with only tap water and the experimental groups were fed with different doses of aqueous extracts of coffee (0.25, 0.5, 0.125 gr/kg) twice daily. After 48 hours, the animals were deeply anesthetized and right kidneys were removed. The Sum slides were prepared and stained with Hematoxyline. Eosin. From each kidney, 15-17 glomeruli were selected and means of glumerular volume were estimated, according to Cavalieri principle and point counting methods.

Our findings revealed that low dose of coffee extraction were led to increase in glomerular volume, but higher doses decreased these volumes. These results were significantly different form control group (p<0.05).

It seems that decrease in glomerular volume leads glomeruloschlorosis and reduction of glomerular filtration rate. However, there should be more investigation such as urea and cratinine measurement to calrify the exact mechanisms.