Histopathological Changes in Organs Due to High Environmental Heat in Male Wistar Rats

Background: Environmental heat significantly affects the morphological and histological structures of mammals. This study aims to identify the histopathological changes induced by high environmental temperatures, specifically hyperthermia, in rats. Methods: Twenty male wistar rats (n=20) were divided into two groups: (A) Experimental group (n=10), in which rats were exposed to hyperthermia in a biological oxygen demand (BOD) incubator until death and (B) Control group (n=10), kept at room temperature (24±1oC). Histopathological analysis was performed following standard procedures, including organ extraction, fixation, grossing, washing, dehydration, clearing, embedding, block preparation, section cutting, staining, mounting and microscopic examination. Result: Histopathological examination revealed that hyperthermia caused mild satellitosis and neuronophagia in the brain. The heart exhibited severely congested blood vessels with hemorrhages and cardiomyocytes showed pyknotic changes. In the kidneys, morphological changes included cloudy swelling of tubular epithelial cells with pyknotic alterations in the epithelial cell lining. The liver showed severe congestion in the sinusoid, hepatic artery and portal vein, along with rounding of Kupffer cells. The lungs exhibited hyperplasia of peri-bronchial lymphoid follicles.