Published online Sep 21, 2018. doi: 10.3748/wjg.v24.i35.4028
Peer-review started: June 8, 2018
First decision: July 3, 2018
Revised: July 12, 2018
Accepted: July 22, 2018
Article in press: July 22, 2018
Published online: September 21, 2018
To investigate whether the adipocytes derived hormone adiponectin (ADPN) affects the mechanical responses in strips from the mouse gastric fundus.
For functional experiments, gastric strips from the fundal region were cut in the direction of the longitudinal muscle layer and placed in organ baths containing Krebs-Henseleit solution. Mechanical responses were recorded via force-displacement transducers, which were coupled to a polygraph for continuous recording of isometric tension. Electrical field stimulation (EFS) was applied via two platinum wire rings through which the preparation was threaded. The effects of ADPN were investigated on the neurally-induced contractile and relaxant responses elicited by EFS. The expression of ADPN receptors, Adipo-R1 and Adipo-R2, was also evaluated by touchdown-PCR analysis.
In the functional experiments, EFS (4-16 Hz) elicited tetrodotoxin (TTX)-sensitive contractile responses. Addition of ADPN to the bath medium caused a reduction in amplitude of the neurally-induced contractile responses (P < 0.05). The effects of ADPN were no longer observed in the presence of the nitric oxide (NO) synthesis inhibitor L-NG-nitro arginine (L-NNA) (P > 0.05). The direct smooth muscle response to methacholine was not influenced by ADPN (P > 0.05). In carbachol precontracted strips and in the presence of guanethidine, EFS induced relaxant responses. Addition of ADPN to the bath medium, other than causing a slight and progressive decay of the basal tension, increased the amplitude of the neurally-induced relaxant responses (P < 0.05). Touchdown-PCR analysis revealed the expression of both Adipo-R1 and Adipo-R2 in the gastric fundus.
The results indicate for the first time that ADPN is able to influence the mechanical responses in strips from the mouse gastric fundus.
Core tip: Evidence exists that some white adipose-tissue derived hormones that are involved in the regulation of food intake also influence the motor responses of the gastrointestinal tract. In this view, adiponectin (ADPN) too has been reported to influence food intake but no data concerning its effects on the gastric mechanical activity are available. The present results indicate for the first time that ADPN is able to influence the mechanical responses in strips from the mouse gastric fundus. It could be speculated that these peripheral effects on motor phenomena might represent an additional mechanism engaged by the hormone to control food intake.