scholarly journals Interdependency between mechanical parameters and afferent nerve discharge in remodeled diabetic Goto-Kakizaki rat intestine

2017 ◽  
Vol Volume 10 ◽  
pp. 303-314 ◽  
Author(s):  
Jingbo Zhao ◽  
Jian Yang ◽  
Donghua Liao ◽  
Hans Gregersen
2000 ◽  
Vol 118 (4) ◽  
pp. A173 ◽  
Author(s):  
Anthony J. Kirkup ◽  
Nigel W. Bunnett ◽  
David Grundy

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Yangyang Liu ◽  
Yang Bai ◽  
Yue Pan ◽  
Zhifang Xu ◽  
Yuxin Fang ◽  
...  

The variation of stimulus intensity of manual acupuncture (MA) may produce diverse acupuncture effects. However, the intensity-effect relationship and the underlying mechanism of MA are still elusive. In this study, the effects of MA regulation of gastric motility were investigated after lifting-thrusting MA treatment with four different frequencies (1 Hz, 2 Hz, 3 Hz, and 4 Hz) at ST36. The experiments were conducted on rats with gastric hypomotility caused by atropine. The results showed that the gastric motility amplitude decreased after atropine injection, while the treatment of four types of MA affected the gastric motility amplitude in varying degrees. Specifically, 2 Hz MA exhibited the most effective results, while 4 Hz MA had the least effect; the effects of 1 Hz MA and 3 Hz MA were between the effects induced with 2 Hz and 4 Hz. Furthermore, the response of gastric vagal afferent nerve discharge and gastric motility was examined after MA treatment with frequencies of 2 Hz and 4 Hz, respectively, on ST36 in order to elucidate the mechanism of MA regulation of gastric motility. The results showed that 2 Hz MA was able to increase the amplitude of gastric motility and discharge frequency of gastric vagal afferent nerves, while 4 Hz MA exhibited seldom effects. These findings suggest that gentle MA (2 Hz) has more stimulating effects than strong stimulation with MA (4 Hz) on gastric hypomotility. In addition, gastric motility regulated by MA was associated with vagal afferent nerve activation.


2012 ◽  
Vol 45 (9) ◽  
pp. 1574-1579 ◽  
Author(s):  
Donghua Liao ◽  
Xiao Lu ◽  
Anthony J. Kirkup ◽  
Wen Jiang ◽  
David Grundy ◽  
...  

1997 ◽  
Vol 230 (2) ◽  
pp. 89-92 ◽  
Author(s):  
M.E Kreis ◽  
T.T Zittel ◽  
H.E Raybould ◽  
J.R Reeve ◽  
D Grundy

1996 ◽  
Vol 41 (2) ◽  
pp. 346-351 ◽  
Author(s):  
Kyoji Seno ◽  
Kan Lam ◽  
Joseph W. C. Leung ◽  
Felix W. Leung

2016 ◽  
Vol 310 (6) ◽  
pp. G376-G386 ◽  
Author(s):  
Jian Yang ◽  
Jingbo Zhao ◽  
Pengmin Chen ◽  
Toshiya Nakaguchi ◽  
David Grundy ◽  
...  

Partial intestinal obstruction causes smooth muscle hypertrophy, enteric neuronal plasticity, motility disorders, and biomechanical remodeling. In this study we characterized the stimulus-response function of afferent fibers innervating the partially obstructed jejunum. A key question is whether changes in afferent firing arise from remodeled mechanical tissue properties or from adaptive afferent processes. Partial obstruction was created by placing a polyethylene ring for 2 wk in jejunum of seven rats. Sham obstruction was made in six rats and seven rats served as normal controls. Firing from mesenteric afferent nerve bundles was recorded during mechanical ramp, relaxation, and creep tests. Stress-strain, spike rate increase ratio (SRIR), and firing rate in single units were assessed for evaluation of interdependency of the mechanical stimulations, histomorphometry data, and afferent nerve discharge. Partial intestinal obstruction resulted in hypertrophy and jejunal stiffening proximal to the obstruction site. Low SRIR at low strains during fast distension and at high stresses during slow distension was found in the obstructed rats. Single unit analysis showed increased proportion of mechanosensitive units but absent high-threshold (HT) units during slow stimulation, decreased number of HT units during fast stimulation, and shift from HT sensitivity towards low threshold sensitivity in the obstructed jejunum. Biomechanical remodeling and altered afferent response to mechanical stimulations were found in the obstructed jejunum. Afferents from obstructed jejunum preserved their function in encoding ongoing mechanical stimulation but showed changes in their responsiveness. The findings support that mechanical factors rather than adaption are important for afferent remodeling.


2000 ◽  
Vol 118 (4) ◽  
pp. A840
Author(s):  
Je Lu ◽  
Zong-Seng Huang ◽  
James P. Li ◽  
Ying Zhao ◽  
William Y. Chey

2007 ◽  
Vol 292 (5) ◽  
pp. G1213-G1220 ◽  
Author(s):  
C. Y. Liu ◽  
M. H. Mueller ◽  
D. Grundy ◽  
M. E. Kreis

The central nervous system modulates inflammation in the gastrointestinal tract via efferent vagal pathways. We hypothesized that these vagal efferents receive synaptic input from vagal afferents, representing an autonomic feedback mechanism. The consequence of this vagovagal reflex for afferent signal generation in response to LPS was examined in the present study. Different modifications of the vagal innervation or sham procedures were performed in anesthetized rats. Extracellular mesenteric afferent nerve discharge and systemic blood pressure were recorded in vivo before and after systemic administration of LPS (6 mg/kg iv). Mesenteric afferent nerve discharge increased dramatically following LPS, which was unchanged when vagal efferent traffic was eliminated by acute vagotomy. In chronically vagotomized animals, to eliminate both vagal afferent and efferent traffic, the increase in afferent firing 3.5 min after LPS was reduced to 3.2 ± 2.5 impulses/s above baseline compared with 42.2 ± 2.0 impulses/s in controls ( P < 0.001). A similar effect was observed following perivagal capsaicin, which was used to eliminate vagal afferent traffic only. LPS also caused a transient hypotension (<10 min), a partial recovery, and then persistent hypertension that was exacerbated by all three procedures. Mechanosensitivity was increased 15 min following LPS but had recovered at 30 min in all subgroups except for the chronic vagotomy group. In conclusion, discharge in capsaicin-sensitive mesenteric vagal afferents is augmented following systemic LPS. This activity, through a vagovagal pathway, helps to attenuate the effects of septic shock. The persistent hypersensitivity to mechanical stimulation after chronic vagal denervation suggests that the vagus exerts a regulatory influence on spinal afferent sensitization following LPS.


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