Immunohistochemical localization of adropin in the small intestine of rats

Abstract

The aim of this study was to determine the occurrence and distribution of adropin in the small intestine in control and gastrectomized rats. The study was carried out on 12 Wistar rats. Six control rats (SHO) underwent a sham operation. Six rats were subjected to gastrectomy (Gx); i.e. resection of the antrum and the glandular part of the stomach. Six weeks after the surgery, the rats were sacrificed. The duodenum and middle part of the jejunum were collected for immunohistochemical and immunofluorescence procedures. An immunopositive reaction to ADR was detected in the duodenum and jejunum, in crypts, and in enterocytes located along the entire length of the villi. Furthermore, more intense ADR immunoreactivity was observed in the crypts and villi of the duodenum than in the jejunum. The presence of adropin was also detected in the submucosa and muscularis externa of the duodenum and jejunum, in the cells of Brunner’s gland of the duodenum, and in myenteric and submucosal plexus nerve. The ADR immunoreactivity in the crypts and villi in the duodenum and jejunum was lower in the Gx rats compared to the SHO rats. The ADR distribution in the duodenum and jejunum has also been confirmed in immunofluorescence studies. In conclusion, our data demonstrated ADR expression in all histological layers of the small intestine in the rats. Gx reduced ADR immunoreactivity in the crypts and enterocytes. This may suggest a potential impact of ADR on intestine function such as absorbability and immune reactions. However, further research is needed to explain the ADR role in gastrointestinal functions

Effect of Adropin on Pancreas Exocrine Function in a Rat Model: A Preliminary Study

“…Kumar et al [ 1 ] showed that serum adropin levels were elevated proportionally to the increase in dietary fat intake and suppressed by fasting. Moreover, the immunopositive reaction for ADR in the duodenum, jejunum, crypts, and enterocytes located along the entire length of the villi suggests its role in the functioning of the GI tract [ 5 ]. In the pancreas, ADR was detected in acinar cells [ 3 ] and in the capillaries of the islets of Langerhans [ 36 ].…”

“…ADR34-76, which is derived from its 76-amino acid precursor, has biological activity. Over several years, the presence of adropin in blood and various organs, including the brain, kidneys, heart, blood vessels, pancreas, and small intestine, has been demonstrated [ 2 , 3 , 4 , 5 , 6 ].…”

“…The presence of ADR in the digestive tract was detected in the duodenum and jejunum. It was located in crypts, enterocytes, submucosa, muscularis externa, Brunner’s gland, and myenteric and submucosal plexus nerve [ 5 ]. Aydin et al [ 3 ] indicated the presence of ADR in the acini of pancreas in rats.…”