ラット顎下腺腺房細胞でノルエピネフリンにより誘導される振動性Cl⁻分泌のβ受容体刺激を介する抑制

抄録

Sympathetic stimulation induces secretion of saliva of which volume is smaller than that by parasympathetic stimulation. However, the cellular mechanism is unclear. Since salivary fluid secretion depends on Cl⁻ secretion from acini of salivary glands, we investigated Cl⁻ secretion induced by the sympathetic transmitter, norepinephrine (NE), adopting the gramicidin-perforated patch recording method to measure Cl⁻ secretion as an anion current at the K⁺ equilibrium potential, -80 mV, in acinar cells. NE induced an oscillatory anion current of which amplitude gradually decreased to a steady-state level in submandibular acinar cells. The β-aderenergic antagonist, propranolol, did not induce any current, but inhibited the gradual decrease in the NE-induced current, suggesting that the current is induced via the α-adrenergic stimulation by NE and suppressed via the β-adrenergic stimulation by NE and that the relatively small volume of saliva induced by sympathetic stimulation may be at least partially due to the reduction of Cl⁻ secretion in the acinar cells by the β-adrenergic stimulation. [J Physiol Sci. 2007;57 Suppl:S123]