NMDAR2B/PKA/CREB signaling pathway contributes to esophageal neuropathic pain in gastroesophageal reflux disease

Table 1 mRNA primer sequences

mRNA	Primers	Product length (bp)
NMDAR2B	Primer F 5’ AGCTCAGCGACCTGTATG 3’	204
	Primer R 5’ ACTCCCTCCTCGATTTGG 3’
PKA	Primer F 5' TCCTTTGGGCGAGTGATG 3'	283
	Primer R 5' CGTAGAAACGGGCGTGGG 3'
CREB	Primer F 5' CAGGGAGGAGCAATACAG 3'	148
	Primer R 5' GCACTAGAATCTGCTGTCC 3'
BDNF	Primer F 5' TGGATGAGGACCAGAAGG 3'	115
	Primer R 5' AGAAAGAGCAGAGGAGGC 3'
GAPDH	Primer F 5' GGAGTCTACTGGCGTCTTCAC 3'	237
	Primer R 5' ATGAGCCCTTCCACGATGC 3'

NMDAR: N-methyl-D-aspartate receptor; PKA: Protein kinase A; CREB: cAMP-response element binding protein; BDNF: Brain-derived neurotrophic factor.

Table 2 Serum brain-derived neurotrophic factor concentration

Groups	BDNF (pg/mL)
Control	179.19 ± 13.42
Model	498.74 ± 69.92a
Model + NR agonist	774.58 ± 113.18c
Model + NR antagonist	322.79 ± 44.83b
Model + PKA antagonist	265.63 ± 35.42c
Model + NR antagonist + PKA agonist	384.03 ± 68.42

^aP < 0.001 vs control group.

^bP < 0.01 vs model group.

^cP < 0.001 vs model group.

NR: N-methyl-D-aspartate receptor; PKA: Protein kinase A; BDNF: Brain-derived neurotrophic factor.

Table 3 Behavioral scores for esophageal acid infusion and balloon distension

Groups	Balloon distension	Acid infusion
Control	1.00 (1.00, 2.00)	2.00 ± 0.89
Model	3.00 ± 0.89a	3.00 ± 0.89a
Model + NR agonist	4.17 ± 0.75b	4.17 ± 0.75b
Model + NR antagonist	1.83 ± 0.75b	2.00 ± 0.63b
Model + PKA antagonist	1.83 ± 0.75b	2.00 ± 0.89b
Model + NR antagonist + PKA agonist	3.50 (2.75, 4.00)c	3.50 (2.00, 4.00)c

^aP < 0.05 vs control groups.

^bP < 0.05 vs model group.

^cP < 0.05 vs model + N-methyl-D-aspartate receptor antagonist group.

NR: N-methyl-D-aspartate receptor; PKA: Protein kinase A.