Effect of L-cysteine on colonic motility and the underlying mechanism.
- Author:
Xiao-Jing QUAN
1
;
Bai-Cang ZOU
1
;
Bin QIN
1
;
Fei DAI
1
;
He-Sheng LUO
2
;
Jin-Hai WANG
3
Author Information
1. Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China.
2. Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, China.
3. Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China. xhnkwjh@126.com.
- Publication Type:Journal Article
- MeSH:
Cystathionine beta-Synthase;
Cystathionine gamma-Lyase;
Cysteine;
pharmacology;
Hydrogen Sulfide;
Muscle, Smooth
- From:
Acta Physiologica Sinica
2020;72(3):299-307
- CountryChina
- Language:Chinese
-
Abstract:
The purpose of the present study is to investigate the effect of L-cysteine on colonic motility and the underlying mechanism. Immunohistochemical staining and Western blot were used to detect the localization of the HS-generating enzymes cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE). Organ bath system was used to observe the muscle contractile activities. Whole-cell patch-clamp technique was applied to record ionic channels currents in colonic smooth muscle cells. The results showed that both CBS and CSE were localized in mucosa, longitudinal and circular muscle and enteric neurons. L-cysteine had a dual effect on colonic contraction, and the excitatory effect was blocked by pretreatment with CBS inhibitor aminooxyacetate acid (AOAA) and CSE inhibitor propargylglycine (PAG); L-cysteine concentration-dependently inhibited L-type calcium channel current (I) without changing the characteristic of L-type calcium channel (P < 0.01); In contrast, the exogenous HS donor NaHS increased I at concentration of 100 μmol/L, but inhibited I and modified the channel characteristics at concentration of 300 μmol/L (P < 0.05); Furthermore, L-cysteine had no effect on large conductance calcium channel current (I), but NaHS significantly inhibited I (P < 0.05). These results suggest that L-cysteine has a potential dual effect on colonic smooth muscle and the inhibitory effect might be directly mediated by L-type calcium channel while the excitatory effect might be mediated by endogenous HS.
