Volume 16, Number 23,
Issue of December 1, 1996
pp. 7574-7582
Copyright ©1996 Society for Neuroscience
Reduction of Lower Motor Neuron Degeneration in
wobbler Mice by
N-Acetyl-L-Cysteine
Received April 15, 1996; revised Aug. 8, 1996; accepted Sept. 30, 1996.
Jeffrey T. Henderson,
Mohammed Javaheri,
Susan Kopko, and
John
C. Roder
Samuel Lunenfeld Research Institute, Program in Development and
Fetal Health, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5
The murine mutant wobbler is a model of lower
motoneuron degeneration with associated skeletal muscle atrophy. This
mutation most closely resembles Werdnig-Hofmann disease in humans and
shares some of the clinical features of amyotrophic lateral sclerosis (ALS). It has been suggested that reactive oxygen species (ROS) may
play a role in the pathogenesis of disorders such as ALS. To examine
the relationship between ROS and neural degeneration, we have studied
the effects of agents such as
N-acetyl-L-cysteine (NAC), which reduce free
radical damage. Litters of wobbler mice were given a 1%
solution of the glutathione precursor NAC in their drinking water for a
period of 9 weeks. Functional and neuroanatomical examination of these
animals revealed that wobbler mice treated with NAC
exhibited (1) a significant reduction in motor neuron loss and elevated
glutathione peroxidase levels within the cervical spinal cord, (2)
increased axon caliber in the medial facial nerve, (3) increased muscle
mass and muscle fiber area in the triceps and flexor carpi ulnaris
muscles, and (4) increased functional efficiency of the forelimbs, as
compared with untreated wobbler littermates. These data
suggest that reactive oxygen species may be involved in the
degeneration of motor neurons in wobbler mice and
demonstrate that oral administration of NAC effectively reduces the
degree of motor degeneration in wobbler mice. This
treatment thus may be applicable in the treatment of other lower motor
neuropathies.
Key words:
spinal cord;
murine;
antioxidant;
mutant;
neurodegenerative;
lower motoneuron