Tannic acid (TA) and TA containing beverage have been proved to inhibit Ca2+-activated Cl- channel located apical membrane of the secretory cells. However, their effect on salivary fluid secretion is not well investig...Tannic acid (TA) and TA containing beverage have been proved to inhibit Ca2+-activated Cl- channel located apical membrane of the secretory cells. However, their effect on salivary fluid secretion is not well investigated. We used mouse ex Vivo submandibular gland perfusion technique to identify the general effect of TA and related beverage samples on muscarinic agonist carbachol induced fluid secretion. Green tea inhibited fluid secretion by 64% from the control, where oolong tea was by 53%, and red wine by 43% which was linked with their TA concentration. On the other hand, though TA was contained at 4.7 μM in white wine sample and 33 μM in coffee extract, no adverse effect was observed. In addition, coffee induced salivation in the absence of carbachol. TA had a negative effect on fluid secretion with a concentration dependent manner. The effects of TA on carbachol induced calcium increase showed identical as fluid secretion, which was initially no effect, and then gradually decreased over the time. These results demonstrate that TA directly inhibits the salivary fluid secretion and it affects not only Ca2+-activated Cl- channel but also intracellular Ca2+ increasing mechanisms.展开更多
The physiological and pharmacological responses of an ex vivo mouse submandibular gland were used to study fluid secretion and cell signaling in response to muscarinic stimulation at increasing temperatures. Saliva pr...The physiological and pharmacological responses of an ex vivo mouse submandibular gland were used to study fluid secretion and cell signaling in response to muscarinic stimulation at increasing temperatures. Saliva production at 37°C was 5.5-fold that at 25°C with pilocarpine stimulation and 9.8-fold that at 25°C with cevimeline stimulation. Both of these muscarinic agonists are used clinically. With the experimental agonist carbachol (CCh), saliva secretion was increased with an increase in temperature, but the CCh concentration producing the peak flow was the same in both dose-response curves, suggesting that the muscarinic receptor itself is not responsible for the temperature dependence. Purinergic agonists also induced temperature-dependent saliva production ex vivo. The calcium ionophore A23187 failed to have a significant effect on saliva production. The CCh-induced increase in intracellular Ca2+ also upregulated the initial increase and sustained the plateau phase of saliva flow. Thus, muscarinic receptor stimulation of saliva production is temperature sensitive due to an increase in intracellular Ca2+.展开更多
文摘Tannic acid (TA) and TA containing beverage have been proved to inhibit Ca2+-activated Cl- channel located apical membrane of the secretory cells. However, their effect on salivary fluid secretion is not well investigated. We used mouse ex Vivo submandibular gland perfusion technique to identify the general effect of TA and related beverage samples on muscarinic agonist carbachol induced fluid secretion. Green tea inhibited fluid secretion by 64% from the control, where oolong tea was by 53%, and red wine by 43% which was linked with their TA concentration. On the other hand, though TA was contained at 4.7 μM in white wine sample and 33 μM in coffee extract, no adverse effect was observed. In addition, coffee induced salivation in the absence of carbachol. TA had a negative effect on fluid secretion with a concentration dependent manner. The effects of TA on carbachol induced calcium increase showed identical as fluid secretion, which was initially no effect, and then gradually decreased over the time. These results demonstrate that TA directly inhibits the salivary fluid secretion and it affects not only Ca2+-activated Cl- channel but also intracellular Ca2+ increasing mechanisms.
文摘The physiological and pharmacological responses of an ex vivo mouse submandibular gland were used to study fluid secretion and cell signaling in response to muscarinic stimulation at increasing temperatures. Saliva production at 37°C was 5.5-fold that at 25°C with pilocarpine stimulation and 9.8-fold that at 25°C with cevimeline stimulation. Both of these muscarinic agonists are used clinically. With the experimental agonist carbachol (CCh), saliva secretion was increased with an increase in temperature, but the CCh concentration producing the peak flow was the same in both dose-response curves, suggesting that the muscarinic receptor itself is not responsible for the temperature dependence. Purinergic agonists also induced temperature-dependent saliva production ex vivo. The calcium ionophore A23187 failed to have a significant effect on saliva production. The CCh-induced increase in intracellular Ca2+ also upregulated the initial increase and sustained the plateau phase of saliva flow. Thus, muscarinic receptor stimulation of saliva production is temperature sensitive due to an increase in intracellular Ca2+.
