Distribution of transient receptor potential vanilloid-1 channels in gastrointestinal tract of patients with morbid obesity

Abstract

BACKGROUND Transient receptor potential vanilloid-1 (TRPV1), a nonselective cation channel, is activated by capsaicin, a pungent ingredient of hot pepper. Previous studies have suggested a link between obesity and capsaicin-associated pathways, and activation of TRPV1 may provide an alternative approach for obesity treatment. However, data on the TRPV1 distribution in human gastric mucosa are limited, and the degree of TRPV1 distribution in the gastric and duodenal mucosal cells of obese people in comparison with normal-weight individuals is unknown. AIM To clarify gastric and duodenal mucosal expression of TRPV1 in humans and compare TRPV1 expression in obese and healthy individuals. METHODS Forty-six patients with a body mass index (BMI) of > 40 kg/m 2 and 20 patients with a BMI between 18-25 kg/m 2 were included. Simultaneous biopsies from the fundus, antrum, and duodenum tissues were obtained from subjects between the ages of 18 and 65 who underwent esophagogastroduodenoscopy. Age, sex, history of alcohol and cigarette consumption, and past medical history regarding chronic diseases and medications were accessed from patient charts and were analyzed accordingly. Evaluation with anti-TRPV1 antibody was performed separately according to cell types in the fundus, antrum, and duodenum tissues using an immunoreactivity score. Data were analyzed using SPSS 17.0. RESULTS TRPV1 expression was higher in the stomach than in the duodenum and was predominantly found in parietal and chief cells of the fundus and mucous and foveolar cells of the antrum. Unlike foveolar cells in the antrum, TRPV1 was relatively low in foveolar cells in the fundus (4.92 ± 0.49 vs 0.48 ± 0.16, P < 0.01, Mann-Whitney U test). Additionally, the mucous cells in the duodenum also had low levels of TRPV1 compared to mucous cells in the antrum (1.33 ± 0.31 vs 2.95 ± 0.46, P < 0.01, Mann-Whitney U test). TRPV1 expression levels of different cell types in the fundus, antrum, and duodenum tissues of the morbidly obese group were similar to those of the control group. Staining with TRPV1 in fundus chief cells and antrum and duodenum mucous cells was higher in patients aged ≥ 45 years than in patients < 45 years (3.03 ± 0.42, 4.37 ± 0.76, 2.28 ± 0.55 vs 1.9 ± 0.46, 1.58 ± 0.44, 0.37 ± 0.18, P = 0.03, P < 0.01, P < 0.01, respectively, Mann-Whitney U test). 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 (diabetes: 2.11 ± 0.67 vs 1.02 ± 0.34, P ...

Capsaicin for Weight Control: “Exercise in a Pill” (or Just Another Fad)?

“…Furthermore, capsaicin can cause gastrointestinal distress that, in turn, may suppress the desire to eat more [ 37 , 72 ]. Somewhat unexpectedly, epithelial cells in the human gut were also shown to express functional TRPV1 [ 73 , 74 , 75 ], implying a direct capsaicin effect on the GI mucosa.…”

“…TRPV1-like immunoreactivity was described in the human GI tract, from the stomach ( Figure 5 ) through the duodenum to the colon [ 73 , 74 , 75 ]. In epithelial cells, no difference in TRPV1 expression was found between obese (BMI > 40 kg/m 2 ) and control individuals [ 75 ].…”

Inhibition of Dorsal Root Ganglia Transient Receptor Potential Ankyrin 1 Upregulation Contributes to the Protective Effect of Morphine Against Gastric Mucosal Damage Induced by Water-Immersion Restraint Stress

“…Both TRPV1 and TRPA1 contribute to gastric function. 18 - 21 Unlike TRPV1, TRPA1 is less studied, and little is known about its role in the stomach. 22 …”

Effect of 3 Months-Feeding of a Powder Diet Fortified With Chilli (Guntur, Bird’s Eye, and Naga King) on Superoxide Dismutase Levels in Sd Rat

“…The active component of chilli is Capsaicin (CAP) which is a type of chemical (alkamide) causing a burning sensation on exposure; however, it is also used as a therapeutic agent in case of neuralgia [1,2], anti-inflammatory [3,4], gastroprotective, muscle sprains/strains [5,6], antiobesity [7][8][9][10][11][12], antipruritic [13,14], anti-apoptotic [15,16], anti-oxidant [17], anti-cancer [18,19], neuroprotective functions, cardio-vascular-related diseases, metabolic disorders, and gastric mucosal protection. On the contrary, few studies suggest increasing apoptosis and oxidative stress [15,20].…”