Aging-associated Morphological Changes of Myenteric Plexus in Colon / 胃肠病学

ABSTRACT

Background: The high incidence of gastrointestinal motility disorders in the elderly may be related to the aging of myenteric plexus (MP). Aims: To investigate the aging-associated morphological changes of colonic MP in rats. Methods: Fourteen male Sprague-Dawley (SD) rats were divided into 6-, 18- and 25-month-old groups. HE staining was used to evaluate the morphological changes of MP and its neurons; immunohistochemistry was used to detect the amount of protein gene product 9.5 (PGP9.5), acetylcholine esterase (AChE), neuronal nitric oxide synthase (nNOS) and c-kit positive cells. Results: There were significant differences in area of ganglions (H=8.14, P=0.02), density of ganglions (F=4.12, P=0.046), area of neuronal cell bodies (F=9.60, P=0.00), area of neuronal cell nucleus (H=9.29, P=0.01), number of neurons per ganglion (F=7.60, P=0.01) and numbers of PGP9.5 positive neurons (F=26.11, P=0.00), AChE positive neurons (H=11.83, P=0.00), nNOS positive neurons (F=20.77, P=0.00) and c-kit positive cells (F=14.25, P=0.00) among the three groups. Compared with 6-month-old group, area of ganglions, area of cell bodies, area of cell nucleus in 18-, 25-months-old groups were significantly increased (P<0.05), while density of ganglions, number of neurons per ganglion and numbers of PGP9.5 positive neurons, AChE positive neurons, nNOS positive neurons and c-kit positive cells were significantly decreased (P<0.05). Conclusions: There are obvious signs of MP ageing (or degeneration) and compensation associated with aging, which may be closely related with the decline in gastrointestinal motility and high incidence of gastrointestinal motility disorders in the elderly.