ABSTRACT
The surface areas of corneal endothelial cells from 12- and 18-month-old male Fischer 344 rats fed ad libitum or a calorie-restricted diet were compared. The rats fed the restricted diet in both age groups showed a statistically significant reduction in the mean cell area of the corneal endothelium. The data indicate that dietary restriction retarded the age-related endothelial cell loss and the subsequent enlargement that takes place to compensate for cell loss. This is the first report to suggest that dietary restriction retards age-related cell loss.
Subject(s)
Aging , Cornea/cytology , Diet , Animals , Endothelium/cytology , Energy Intake , Male , RatsABSTRACT
The endothelial cells of the C57BL/6J mouse cornea show a progressive age-related increase in cell area, and an increasing departure from the initial hexagonal form. Mean endothelial surface areas were 304, 386, 458, 499, and 653 micron2 for mice of ages 1, 4, 11, 22, and 27 months, respectively. Increasing cell areas are interpreted to represent a spreading and thinning of surviving cells to compensate for cell loss. These age-related changes correspond to those previously observed in the rat, although the rat endothelial cells tend to have smaller cell areas and show less variation at each age studied.
Subject(s)
Aging , Cornea/cytology , Animals , Endothelium/ultrastructure , Female , Mice , Mice, Inbred C57BL , Microscopy, ElectronABSTRACT
The deep band of the plantar aponeurosis is a variable structure formed by fibers from both the medial and lateral portions of the plantar aponeurosis. This band courses directly to the plantar ligament of the fourth metatarsophalangeal joint. Proximally it is superficial. Distally it passes deep to the tendons of the flexor digitorum longus to attach at the metatarsophalangeal joint. The second plantar and third and fourth dorsal interosseous muscles as well as the transverse head of adductor hallucis have attachments to the deep aponeurotic band. This band becomes taut when the proximal phalanx of the fourth toe is extended. No recent references to this structure could be found. The function of the deep band of the plantar aponeurosis is unknown, although the anatomical arrangement may make it important in stabilizing the fourth ray of the foot during locomotion.
Subject(s)
Fascia/anatomy & histology , Foot/anatomy & histology , Fascia/physiology , HumansABSTRACT
The endothelial cells of the rat cornea show a progressive decline in numbers and an increase in pleomorphism from age 6 months to 30 months. These age-related changes correspond closely to those reported in the human cornea from approximately age 20 to age 70 years. The corneal endothelium may be found useful as an index of physiological aging in these and other mammals.
