tellurium and Central-Nervous-System-Diseases

Topics: Arsenic; Cadmium; Central Nervous System Diseases; Chemical and Drug Induced Liver Injury; Cobalt; Copper; Gastrointestinal Diseases; Heart Diseases; Humans; Liver; Lung Diseases; Manganese Poisoning; Molybdenum; Nickel; Occupational Medicine; Selenium; Tellurium; Tin; Trace Elements; Vanadium; Zinc

To investigate the influence of squalene on the nervous system, adult male Wistar rats were injected with squalene subcutaneously with 20 g/kg of the body weight for 4 consecutive days. After 7 or 30 days from the initiation of the experiment, brain and ischiadic nerves were harvested for electron microscopy. Squalene affected mostly PNS targeting Schwann cells and myelin sheaths. Accumulation of lipid-like droplets in the myelin sheaths in the PNS and in the neurons in the brain cortex, hypertrophy of endothelium, and sometimes endothelial apoptosis in blood vessels, and increased synthesis of collagen in the ischiadic nerve were characteristic for developed squalene encephaloneuropathy.

Topics: Animals; Apoptosis; Central Nervous System Diseases; Demyelinating Diseases; Lipids; Male; Myelin Sheath; Peripheral Nervous System Diseases; Rats; Rats, Wistar; Schwann Cells; Squalene; Tellurium

We observed demyelination and rapid reparative remyelination in the cerebral white matter, cortex and optic nerve of adult rats intoxicated with sodium tellurite (1.25 and 6.25 mg/kg Te4+). Hypomyelination dominated by the seventh day and its intensity was dependent on the dose Te4+. Reparative myelination was not completed in the brains 30 days after the intoxication with tellurium. In addition to myelin changes, signs of neuronal and astrocytic damage were seen: dark neurons and swelling of the astrocytic processes and synapses in the cerebral cortex. We postulate that tellurium evokes not only the myelin sheath and a myelin forming glia damage but also ultrastructural changes in some axons, and reaction of fibrillar astrocytes.

Topics: Animals; Astrocytes; Axons; Central Nervous System Diseases; Cerebral Cortex; Demyelinating Diseases; Microscopy, Electron; Myelin Sheath; Optic Nerve; Rats; Rats, Wistar; Tellurium