Immunohistochemical study of fiber types in human extraocular muscles.
Fiber types in human extraocular muscle (h-EOM) were examined immunohistochemically with antibodies against slow tonic (anti-ALD) and slow twitch (anti-SOL) myosins. Four types of muscle fiber in h-EOM were distinguishable according to their reactivities with these antibodies. Groups 1 and 2 fibers reacted with both antibodies, group 1 fibers showing stronger reactivity than group 2 fibers with anti-ALD. Group 3 fibers reacted only with anti-SOL. Group 4 fibers did not react with either antibody. The latter were the most common, and were the main fibers in both the peripheral (outer orbital) and central zones of h-EOM. The next most common were group 1 fibers, which were located mainly in the peripheral layer. Group 2 fibers were less common, but were the second most common type in the central layer. Group 3 fibers were only minor constituents. Multiple innervations were observed in some fibers of groups 1 and 2, and group 1 fibers were suggested to be slow tonic myofibers in h-EOM. These specific immunohistochemical and physiological features of h-EOM seem to be the basis of the low morbidity seen in the usual types of muscular dystrophy.
Fujii
Y
Y
First Department of Pathology, Tokushima University School of Medicine, Japan.
Abe
J
J
Nunomura
S
S
Moriuchi
T
T
Hizawa
K
K
D000368:Aged; D000369:Aged, 80 and over; D005123:Eye; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008875:Middle Aged; D009132:Muscles / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D009218:Myosins / Q000378:metabolism*
D009218:Myosins