ABSTRACT
SUMMARY Our work focused on the studies on the expression and function of transient receptor poten -tial vanilloid subtype 1 ( TRPV1) in the submandibular gland .By using reverse transcription-polymerase chain reaction ( RT-PCR ) , Western blotting , and immunofluorescence , our data demonstrated the expression and distribution characteristics of TRPV 1 in rabbit and human submandibular glands , as well as rat submandibular gland cell line SMG-C6.Furthermore, the possible intracellular signal molecules involved in the TRPV1-modulated saliva secretion were explored .Activation of TRPV1 increased the intracellular Ca2+concentration, upregulated the expression of aquaporin 5 (AQP5), the main transpor-ter that mediate water secretion through transcellular pathway , and led to AQP5 redistribution .Extracel-lular signal-regulated kinase 1/2 ( ERK1/2 ) was involved in the TRPV1-regulated AQP5 content. Besides, TRPV1 activation also modulated the expression , distribution, and function of tight junction protein, and increased paracellular permeability .ERK1/2 and myosin light chain 2 ( MLC2 ) were responsible for the regulation of TRPV1on tight junction properties.Taken together, our work suggested that TRPV1 was a potential target to promote saliva secretion , and activation of TRPV1 might provide a new and safe therapeutic strategy to ameliorate submandibular gland hypofunction .
ABSTRACT
Objective To study the expression of the capsaicin receptor,vanilloid receptor subtype 1(VR1) immunoreactivity,their morphology and distribution in afferent fibers of rat esophagus. Methods Laser scanning confocal microscope combined with immunohistochemical double labeling methods were used. Results VRl-like immunoreactivity was observed on nerve fibers and terminalis within mucosa,submucosa,muscle layer and surrounding blood vessel throughout esophagus.Their profiles were fine fibers with some spiny,possessing varicose-like swellings along their lengths.About(92.3?3.7)% VR1 positive fibers co-localized with CGRP immunoreactivity,which representing large majority of afferent fibers in the esophagus was extrinsic in origin with cell bodies located in dorsal root ganglia.In dorsal root ganglion,VR1 was expressed in small-and middle-sized cell bodies.About(41.5?4.5)% VRl-immunoreactive neurons co-stained with CGRP and(67.9?3.2)% CGRP positive neurons co-localized with VR1.In nodose ganglion,the expression of VR1 was similar with dorsal root ganglion,but CGRP immunoreactive neurons very few.Only(4.7?1.4)% VR1 positive neurons co-stained with CGRP.Conclusion These results suggest that VR1 is expressed in afferent fibers in the wall of the rat esophagus which is in origin in dorsal root ganglion.
ABSTRACT
PURPOSE: This study was performed to investigate the changes in nerve growth factor (NGF), and vanilloid receptor subtype 1 (VR1), after the relief of bladder outlet obstruction, and to look at how these changes participate in functional changes of the bladder. MATERIALS AND METHODS: 50 Wistar male rats, weighing approximately 250-300g, were used for this study, and divided into two groups: 10 controls and 40 experimental. The control group consisted of sham operated animals. The experimental group was obstructed for 3 weeks by partial urethral ligation. After 3 weeks, the obstruction was relieved by urethral deligation. Cystometrograms (CMG) were performed 3 weeks after deligation. On the basis of CMG, the experimental group was subdivided into normalised, and unstable, bladder groups. The bladders of each group were dissected out, weighed and immunohistochemical staining for NGF and VR1 analysis, performed. RESULTS: Compared with the control group, bladder weights of the normalised, and unstable, bladder groups were increased (p<0.05). On CMG, there was no significant difference in contraction pressure among the 3 groups. The contraction interval of the unstable bladder group was markedly decreased compared with that of the control and normalised groups. On immunohistochemical staining, contrary to the control and normalised groups, the intensity of staining for NGF in the unstable bladder group increased in the basal layer, submucosa and interfascicular layers. VR1-immunoactive nerve fibre-like structures were seen in the basal and submucosal layers in the unstable bladder group, and there were no VR1-like structures in the muscle layer. However, there were no VR1-like structures any of the layers of the control and normalised groups. CONCLUSIONS: Increased NGF and VR1 may be related to persistent unstable bladder or bladder irritative symptoms after rectifying a bladder outlet obstruction.