THE UPTAKE OF METHYL MERCURY (203Hg) IN DIFFERENT TISSUES RELATED TO ITS NEUROTOXIC EFFECTS

• Published in: The Journal of pharmacology and experimental therapeutics Vol. 187; no. 3; p. 602
• Main Authors: Somjen, G G, Herman, S P, Klein, R, Brubaker, P E, Briner, W H, Goodrich, J K, Krigman, M R, Haseman, J K
• Format: Journal Article
• Language: English
• Published: United States American Society for Pharmacology and Experimental Therapeutics 01.12.1973
• Subjects: Animals; Autoradiography; Brain - metabolism; Cerebellum - metabolism; Chromium Radioisotopes; Ganglia - metabolism; Ganglia, Spinal - metabolism; Kidney - metabolism; Kidney Cortex - metabolism; Liver - metabolism; Mercury Isotopes; Methylmercury Compounds - analysis; Methylmercury Compounds - metabolism; Methylmercury Compounds - toxicity; Nervous System - drug effects; Nervous System Diseases - chemically induced; Peripheral Nerves - metabolism; Rats; Serum Albumin, Radio-Iodinated; Spinal Cord - metabolism; Spinal Nerve Roots - analysis; Spleen - metabolism; Time Factors
• ISSN: 0022-3565; 1521-0103

Rats were treated by subcutaneous injection of methyl mercury hydroxide containing the radioactive isotope 203 Hg. The Hg concentration of organ samples was determined by radioassay at the end of one to four weeks of treatment. Of parts of the nervous system, spinal dorsal root ganglia contained the highest concentration of Hg, followed closely by the cerebral cortex and the cerebellum, then the subcontical part of the forebrain. Spinal cord, spinal roots and peripheral nerves contained significantly less Hg than the sensory ganglia. There was no difference in the Hg content of dorsal and ventral roots. Hg levels of non-neural tissues are also presented. The amount of blood remaining in organ samples was estimated, and a correction was applied to allow for the Hg contained in the residual blood. On autoradiograms made of tissues of animals treated with Me- 203 Hg, there were more reduced grains of silver over gray matter than over white matter and more in neurons than in glia, satellite or Schwann cells. The results are consistent with the idea derived from other investigations that spinal ganglia are the primary targets of poisoning by MeHg + , and that sensory axons degenerate because their parent cell bodies are damaged. Differences in the amount of poison accumulated by cells appear to play a part in determining the selectivity of its effect, but cannot be the only cause of variations of sensitivity of tissues.