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

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

Age relatea changes in the fundic mucosa of stomach of male albino rats [histological and immunohistochemical study]

Although the incidence of gastric cancer increases with advancing age, the precise role of aging remains a matter of controversy. This study aimed to evaluate the histological and immunohistochemical changes in the rat fundic mucosa of stomach during aging. Fifteen male albino rats were classified into group A [4 months old], group B [18 months old] and group C [24 months old]. Their stomach were dissected out and processed for light and electron microscope examination. Paraffin sections were stained with H and E, Masson's trichrome, PAS stain and immunohistochemically for detection of BCL-2 [antiapoptotic marker]. Area% of collagen fibers and positive BCL-2 immunoreaction were estimated morphometrically and statistically analysed. Examination of fundic mucosa of group B revealed irregular atrophic fundic glands widely separated by abundant collagen fibers and congested blood vessels. Parietal cells contained narrow intracellular canaliculi, few microvilli and many tubulovesicles while degenerative changes were seen in chief cells and enteroendocrine cells. The group C, the fundic glands showed marked disorganization, atrophy, distorsion, ulceration and excessive fibrosis. Little mucous was observed in the mucous neck cells. The area% of collagen fibers was significantly increased in group B as compared to group A and in group C as compared to group B. Regarding apoptosis, the area% of positive BCL-2. Immunoreaction was significantly increased in group B as compared to group A and in group C as compared to group B. These results indicated progressive attenuation of apoptosis with advancing age. Ultrastructurally, degenerative changes appeared in chief cells, parietal cells and enteroendocrine cells. The present study revealed that aging is associated with dramatic progressive changes in the histological structure of the rat Fundic mucosa. These alternations may predispose the stomach to the malignant transformation. So, early diagnosis and treatment of Heliconbacter pylori infection in old patients are recommended. Also, further studies are needed to detect the antioxidants that protect the stomach of the elderly from oxidative stress