Morphological changes during acute experimental short-term hyperthermia.

Wistar rats have been exposed to progressively higher temperatures for 30 minutes to 40.5 degrees Celsius. The animals were sacrificed 30 minutes after cessation of exposure. Harvested organs (heart, lung, liver, pancreas, kidneys, and adrenal gland) show numerous vascular lesions. Massive red blood cells extravasation and vascular stasis partially fragments the myocardial fibers. Pulmonary capillary dilatation and red blood cells intra-alveolar extravasation cause a hemorrhagic alveolitis that tends to a red hepatization. The liver responds by dilating centrolobular veins, vessels in port area and by granulo-vacuolar dystrophy. Pancreas seems less affected. Vascular hyperemia is discrete while in kidney the vascular spaces are narrowed and the proximal and distal tubules cloudy intumescent appears. In suprarenal gland appear many interstitial capillary dilatation and blood cells extravasation among cell nests of medulla. All these changes induce functional organ failure.

Scanning electron microscopy of vascular corrosion casts--standard method for studying microvessels.

Scanning electron microscopy (SEM) of vascular corrosion casts (microvascular corrosion casting/SEM method) is a standard method, which allows three-dimensional visualization with good resolution of the normal and abnormal microvessels, including the capillaries of various organs and tissues. SEM of vascular corrosion casts can obtain qualitative as well as quantitative informations important to anatomists, pathologists and clinicians. Considering these, the history, the advantages and the main steps of this technique including general morphological characteristics of vascular casts observed in SEM are reviewed in this paper. Corrosion casts done by the author representing the microvascular organization of the rat liver and kidney observed in SEM are, also, presented.