Ultrastructural changes in the kidney following chronic exposure to low levels of halothane

Rats were subjected to chronic exposure to low levels of halothane (10 and 500 ppm for 8 and 4 weeks, respectively). The ultrastructural changes in the kidneys were studied. Animals exposed to 10 ppm halothane demonstrated chronic degenerative changes in the proximal convoluted tublues, including proliferation and membranous whirling of the basal infoldings of some epithelial cells and membranous degeneration of the mitochondria to form membranous bodies within the cellular cytoplasm. These pathologic changes were even more extensive and exaggerated in animals exposed to 500 ppm halothane. Fusion of the membranous bodies to form large membranous plaques and coalescence of lysosomes to form irregulary shaped cytoplasmic dense bodies were frequently found. Swelling of the mitochondria and areas of focal cytoplasmic degradation were also observed. Extrustions of large cytoplasmic masses containing mitochondria. clusters of smooth endoplasmic retriculum and ribosomes into the tubular lumen were frequently observed. Accumulation of spherical microparticles within the tubular basement membranes were also a prominent finding. The present investigation clearly indicated that halothane is nephrotoxic and may be considered as an occupational hazard.