Histopathologic effects of formaldehyde exposure on rat kidney

Background and Formaldehyde is a chemical traditionally used for fixing the cadaver. It is vaporized during dissection and practical studying on cadaver. Studies show that this vapour can cause some clinical sympotms such as throat, eye, skin and nasal irritation. This study was designed to determine the histopathological changes of rat kidney tissue exposed to formaldehyde for 18 weeks. This study was performed on 28, 6-7 weeks postnatal albino Wistar rats. The rats were divided into 3 case groups (E1: 4hrs/d, 4d/w E2: 2hrs/d, 4d/w E3: 2hrs/d, 2d/w) and one control group (C). The kidney specimens were sectioned and stained with H&E technique for histopathological study. In all histopathology sections of groups E1, E2 and E3, the following similar changes were observed: Mild congestion in the glumeroles, focal congestion and vacuolar (hydropic) degeneration of tubular cells only mild non-specific congestion in renal vessels. There were no evidences of fibrotic change or inflammatory cells infiltration among interstitial tissue. Also there were no abnormalities in the staining of nucleus and cytoplasm. In Control group (C), no histopathologic changes were observed. The results of this study showed that formaldehyde vapour with a concentrations used in our study, can not induce histopathologic changes which could be detectable by light microscope. Also, there is no direct relationship between the duration of exposure to formaldehyde vapour and the intensity of histopathologic changes in the kidney.