Age-related changes in the myenteric plexus of the gastric fundus in albino rats: histological and immunohistochemical study

ABSTRACT

Aging is believed to affect the structure and function of the enteric nervous system in the gastrointestinal tract. This work was designed to study the histological changes that might occur in the myenteric plexus of rat gastric fundus during aging. Thirty male albino rats were used in this study and divided equally into three groups group A [which included 4-month-old rats], group B [which included 18-monthold rats], and group C [which included 24-month-old rats]. All the animals were anesthetized, and their stomachs were dissected out and processed for light and electron microscope examination. Also, immunohistochemical staining was carried out for the detection of protein gene product [PGP 9.5] and Bcl-2 proteins. The area% of myenteric ganglia was also determined. The results were analyzed statistically. With age, in group B [early senile], there was obvious neuronal loss and few gaps in the myenteric plexus, with a significant decrease in the number of PGP-positive neurons and moderate immunoreactions for the Bcl-2 protein. Glial cells had cytoplasmic vacuoles and nerve cells had peripheral condensation of heterochromatin in their nuclei. The myenteric plexus of the rats of group C [late senile] showed nerve cell bodies with apoptotic nuclei and cytoplasmic vacuolations. Many large cavities and eosinophillic cellular infiltration were observed within the neuropil. There was a marked apparent decrease in PGP 9.5-positive neurons and minimal immunoreactions for the Bcl-2 protein. Also, the area of myenteric ganglia increased with advancing age. In the current study, it was found that the myenteric plexus of the gastric fundus showed histological and immunohistochemical changes during aging, which may potentially be an explanation for the gastrointestinal tract disturbance in elderly individuals