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 .