Progress on the Mechanism of Visceral Hypersensitivity in Nonerosive Reflux Disease

Table 1

NERD and acid-sensitive receptor expression level.

References	State	Research objects	Methods	Results
Kandulski et al. [16]	Germany	NERD group (); Healthy control group ()	Biopsies were taken at 2 cm above the squamocolumnar junction at the 3 o’clock position, PAR-2 expression was analyzed by quantitative reverse transcription- (RT-) PCR and immunohistochemistry.	PAR-2 protein expression: NERD group (); Healthy control group () ()
Kim et al. [17]	South Korea	NERD group (); Healthy control group ()	Biopsies using standard biopsy forceps at a fixed position 3 cm above the squamocolumnar junction. PAR-2 RNA expression was assessed by qPCR.	PAR-2 mRNA expression: NERD group (); Healthy control group () ()
Yoshida et al. [13]	Japan	NERD group (); Healthy control group ()	Biopsies for mRNA analysis were taken from the esophageal squamous mucosa at 5 mm above the squamocolumnar junction. The mRNA expression level of TRPV1 and PAR-2 was assessed by real-time RT-PCR and enzyme immunoassay.	Compared with the healthy control group, mRNA of TRPV1 and PAR-2 were significantly elevated in the NERD group ().; TRPV1 mRNA in the healthy control group could not be detected
Guarino et al. [18]	Italy	NERD group (); Healthy control group ()	Biopsies were taken from the esophageal squamous mucosa at 5 cm above the squamocolumnar junction, relative optical density of TRPV1 protein was assessed by Western blot analysis, and TRPV1 RNA expression was assessed by qPCR.	TRPV1 mRNA expression: NERD group (); Healthy control group () (); Relative optical density of TRPV1 protein: NERD group (); Healthy control group () ()
Ustaoglu et al. [19]	Britain	NERD group (); ERD group (); BE group ()	Biopsies obtained from the distal esophageal mucosa were costained with TRPV1; TRPV1 RNA expression was assessed by qPCR.	NERD patients had significantly increased expression of TRPV1 on superficial sensory nerves compared to ERD () or BE ()
Silva et al. [20]	Brazil	Experimental group (NERD was surgically induced in Swiss mice); Control group (sham surgery)	Collect mice esophagus; TRPV1 protein expression was assessed by Western blot analysis.	TRPV1 protein expression: Experimental group (); Control group () ()
Patcharatrakul et al. [21]	Thailand	NERD group (); Healthy control group ()	Two groups underwent single-photon emission computed tomography after ingesting 2 g of chili or placebo in capsules in a randomized double-blind crossover fashion with a one-week washout period to compare gastric accommodation (GA).	GA: NERD group ( mL); Healthy control group ( mL) ()

RT-PCR: reverse transcription-polymerase chain reaction; qPCR: quantitative real-time polymerase chain reaction; ERD: erosive reflux disease; BE, Barrett esophagus; GA: gastric accommodation.