Effects of methylmercury on the motor and sensory innervation of the rat extensor digitorum longus muscle

Journal Article · Mon Jun 01 04:00:00 EDT 1987 · Environ. Res.; (United States)

DOI:https://doi.org/10.1016/S0013-9351(87)80060-9· OSTI ID:5714753

Yip, R K; Riley, D A

The histochemical study examined the effects of chronic methylmercury (MeHg) intoxication on the motor and sensory innervation of extensor digitorum longus muscles. Light microscopic examination of silver-stained axons in the intramuscular nerve bundles of MeHg-treated rats showed Wallerian-like degeneration and a reduction in the number of nerve fibers. Disrupted axons were predominantly sensory because 22.2% of spindle afferents (I/sub a/) and 90.0% of Golgi tendon organ (I/sub b/) sensory fibers were completely degenerated whereas less than 1% of motor ending were totally destroyed. Partial disruption occurred in the cholinesterase and motor terminals of 13.7% of endplates. Their results demonstrated greater vulnerability of sensory nerves than of motor nerves to MeHg-induced degeneration. Thus, the abnormal reflexes, ataxia, and muscle weakness following MeHg poisoning appear related to reduction of proprioceptive feedback from muscles and tendons irradiation to the documented lesions in the central nervous system.

• Research Organization: Medical College of Wisconsin, Milwaukee
• OSTI ID: 5714753
• Journal Information: Environ. Res.; (United States), Journal Name: Environ. Res.; (United States) Vol. 43:1; ISSN ENVRA
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL TISSUES
ANIMALS
BIOLOGICAL FUNCTIONS
BODY
CHRONIC INTAKE
FUNCTIONS
INTAKE
MAMMALS
MERCURY COMPOUNDS
METHYLMERCURY
MUSCLES
NERVE TISSUE
ORGANIC COMPOUNDS
ORGANIC MERCURY COMPOUNDS
PATHOLOGICAL CHANGES
RATS
RODENTS
TISSUES
TOXICITY
VERTEBRATES