Lethal hypothermia in an animal model, not associated with basal renal epithelial vacuolization

A rodent model was used to evaluate the association between hypothermia and basal vacuolization in renal tubular epithelial cells. 28 Sprague Dawley rats were anaesthetized in non-stressful conditions and placed two at a time into a cooling chamber. Body core temperatures dropped to a minimum of 7-10 °C, causing death under anaesthesia at times varying from 120 to 240 min. The animals were then subjected to necropsy; the kidneys were removed and placed in 10% buffered formalin. Examination of haematoxylin and eosin-stained renal sections failed to reveal basal vacuolization of renal tubular epithelial cells in any of the 28 animals. In this model, no evidence of subnuclear lipid vacuolization of renal tubular cells could be demonstrated despite significant and eventually lethal hypothermia. These results lend support to the hypothesis that the basal vacuolization in hypothermia may be a manifestation of a more complex pathophysiological pathway rather than being due simply to low body core temperatures.