2 research outputs found
Skeletal muscle abnormalities associated with occupational exposure to mercury vapours
There is scarce information on the possible
effects of chronic exposure to mercury on skeletal
muscle. Dental personnel are frequently exposed to
inhalation of metallic mercury vapours. The skeletal
muscle of five technicians and one dentist (females, age
36-55) was studied. All of them presented symptoms of
chronic mercury poisoning. Needle biopsy was taken
from the quadriceps femoris muscle and samples were
prepared for light microscope histochemistry and for
transmission electron microscopy. Selective atrophy of
type IIB muscle fibres was found in patients, and in one
of them there was fibre grouping. Most of the muscles
showed increased fibre area per capillary. Atrophy was
confirmed by the ultrastructural study, demonstrating
increase of intermyofibrillar spaces, loss of myofibrils or
complete disappearance in some fibres, and sarcolemmal
folding. Splitting of the fibres was also found. Some
capillaries were altered, showing endothelial infoldings
into the lumen, thickened basement membrane and
partial or total occlusion. The alterations found in
muscle may be secondary to nerve damage, to ischemia
caused by capillary lesion andlor to a direct effect of
mercury on muscle fibre proteins