Okada Y, Fujiyama R, Miyamoto T, Sato T
Department of Physiology, Nagasaki University School of Dentistry, Japan.
Chem Senses. 1996 Dec;21(6):739-45. doi: 10.1093/chemse/21.6.739.
The effect of arginine vasopressin (AVP) on the membrane properties was analyzed in isolated bullfrog taste cells using a perforated whole-cell patch-clamp technique. AVP (100 nM) induced three kinds of responses in rod-type taste cells: appearance of inward current, inhibition of voltage ramp-induced outward current and enhancement of the outward current. The Ca(2+)-ionophore ionomycin (3 microM) also induced inward current in taste cells. A membrane-permeable cAMP analog, 8-CPT-cAMP (0.3 mM) inhibited voltage ramp-induced outward current in some rod cells, but enhanced the current in other rod cells. The results suggest that AVP may increase either intracellular Ca2+ level or cAMP level in taste cells, modulating the membrane excitability.
采用穿孔全细胞膜片钳技术,在分离的牛蛙味觉细胞中分析了精氨酸加压素(AVP)对膜特性的影响。AVP(100 nM)在杆状味觉细胞中诱导出三种反应:内向电流的出现、电压斜坡诱导的外向电流的抑制以及外向电流的增强。钙离子载体离子霉素(3 microM)也在味觉细胞中诱导出内向电流。一种膜通透性cAMP类似物8-CPT-cAMP(0.3 mM)在一些杆状细胞中抑制电压斜坡诱导的外向电流,但在其他杆状细胞中增强了该电流。结果表明,AVP可能会增加味觉细胞内的Ca2+水平或cAMP水平,从而调节膜兴奋性。