Retrospective Study
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World J Clin Cases. Jan 7, 2022; 10(1): 79-90
Published online Jan 7, 2022. doi: 10.12998/wjcc.v10.i1.79
Distribution of transient receptor potential vanilloid-1 channels in gastrointestinal tract of patients with morbid obesity
Unal Atas, Nuray Erin, Gokhan Tazegul, Gulsum Ozlem Elpek, Bülent Yıldırım
Unal Atas, Gokhan Tazegul, Department of Internal Medicine, Akdeniz University Medical School, Antalya 07070, Turkey
Nuray Erin, Department of Pharmacology, Akdeniz University Medical School, Antalya 07070, Turkey
Gulsum Ozlem Elpek, Department of Pathology, Akdeniz University Medical School, Antalya 07070, Turkey
Bülent Yıldırım, Department of Gastroenterology, Akdeniz University Medical School, Antalya 07070, Turkey
Author contributions: Atas U, Erin N, and Yildirim B designed the study and collected materials; Elpek GO evaluated the histopathological findings; Tazegul G provided analytical tools; all authors assessed the results; Atas U and Tazegul G wrote the manuscript; Erin N, Yildirim B and Elpek GO critically revised the draft; and all the authors checked the final version of the manuscript.
Institutional review board statement: The study was reviewed and approved by the Scientific Research Projects Coordination Unit of Akdeniz University, No. 2333.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: There is no conflict of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Gulsum Ozlem Elpek, MD, Professor, Research Assistant Professor, Department of Pathology, Akdeniz University Medical School, Dumlupınar Bulvarı, Antalya 07070, Turkey. elpek@akdeniz.edu.tr
Received: April 21, 2021
Peer-review started: April 21, 2021
First decision: June 13, 2021
Revised: June 25, 2021
Accepted: November 23, 2021
Article in press: November 23, 2021
Published online: January 7, 2022
Processing time: 252 Days and 21.9 Hours
ARTICLE HIGHLIGHTS
Research background

New agents and methods are sought to prevent and treat obesity, which is a serious public health problem.

Research motivation

It has been reported that capsaicin acting on transient receptor potential vanilloid-1 (TRPV1) increases thermogenesis, lipid oxidation and energy expenditure and prevents diet-induced obesity.

Research objectives

This study aimed to compare obese individuals with normal individuals in terms of TRPV1 staining in the gastroduodenal mucosa and to determine the distribution of TRPV1 in gastroduodenal mucosa cells.

Research methods

Total 46 morbidly obese patients and 20 control patients were included. Simultaneous biopsies from the fundus, antrum, and duodenum tissues were obtained from subjects. Evaluation with anti-TRPV1 antibody was performed separately according to cell types in the fundus, antrum, and duodenum tissues using an immunoreactivity score (IRS).

Research results

TRPV1 Levels in fundus, antrum, and duodenum tissues of the morbidly obese patients were similar to those of the control group. When the staining of the cells was compared with other tissue sites in terms of staining properties, the levels of TRPV1 in antrum and fundus cells in the stomach were higher than those in duodenal cells. The highest IRS was observed in fundus parietal cells, foveolar cells in the antrum, and absorptive cells in the duodenum. When the staining levels of the same type of cells in different tissues were compared, cells of the antrum had the highest staining intensity, followed by the fundus and duodenum. In addition, Staining with TRPV1 in fundus chief cells and antrum and duodenum mucous cells was higher in patients aged 45 years and older than in patients under 45 years. The mean staining levels of TRPV1 in duodenal mucous cells in patients with diabetes and hypertension were higher than those in patients without diabetes and hypertension.

Research conclusions

We have demonstrated that the expression of TRPV1 is similar in the gastroduodenal mucosa of morbidly obese patients and control subjects. TRPV1 expression was significantly higher in parietal and chief cells of the fundus and mucous and foveolar cells in the antrum, which affects digestion, mucosal protection, and motility. In addition, the unchanged expression of gastric and duodenal TRPV1 in the obese patient group suggests that drugs targeting TRPV1 may be effective in these patients.

Research perspectives

There is a need for more comprehensive long-term studies that can reveal the pathophysiology of obesity for the prevention and treatment of obesity.