Table 1.
Changes in body weight (BW) and absolute and relative weight of adductor longus (AL) muscle.
Figure 1.
Mid-belly regions of adductor longus muscles sampled after 16-day unloading or cage housing.
Cross-sections were stained immnohistochemically for fast myosin heavy chain. Red fibers are fast-twitch (type II or I+II) fibers.
Figure 2.
Region-specific responses of fiber cross-sectional area in adductor longus muscle.
Mean±SEM. n = 5 in each group/stage. Pre, Day 16, and Day 32: Before hindlimb unloading, immediately after termination of 16-day unloading or cage housing, and 16 days after ambulation on the floor or 32 days of cage housing, respectively. I, II, and I+II: Fibers expressing pure type I (slow) and II (fast), and co-expressing both type I and II myosin heavy chain. *, †, and §: p<0.05 vs. pre, age-matched control, and respective group at Day 16, respectively. a: p<0.05 vs. the rostral region.
Figure 3.
Region-specific responses of fiber phenotypes in adductor longus muscle.
Mean±SEM. n = 5 in each group/stage. See Figure 2 for the symbols and abbreviations.
Figure 4.
Myonuclear number per fiber and mm fiber length, fiber cross-sectional area (CSA), and myonuclear domain.
Mean±SEM. n = 5 in each group/stage. See Figure 2 for the symbols and abbreviations.
Figure 5.
Satellite cell number per entire single fiber and mm fiber length.
Responses of both total (Pax7-positive) and mitotic active (BrdU-positive) satellite cells are shown. Mean±SEM. n = 5 in each group/stage. BrdU: 5-bromo-2′-deoxyuridine. See Figure 2 for other symbols and abbreviations.
Figure 6.
Time course changes of the mean (±SEM) electromyogram activities.
Absolute activity (V/hr) and activity relative to the pre-unloading (pre) level on the floor (100%) in the rostral and caudal regions of adductor longus muscle in response to hindlimb unloading and ambulation recovery are shown. n = 5 in each region. Further, typical EMG patterns and mean activity during quadrupedal rest on the floor are also shown. *: p<0.05 vs. pre-experimental level on the floor. †: p<0.05 vs. the rostral region.
Figure 7.
The mean angles of hip joint of rat and perimeters of adductor longus muscle.
Changes of these parameters during quadrupedal resting position on the floor and hindlimb unloading are shown.
Figure 8.
Sarcomere length of adductor longus muscle fibers.
The mean levels during quadrupedal rest on the floor and hindlimb unloading are shown. Mean±SEM. n = 5 in each group/stage. *: p<0.05 vs. each region on the floor.