Pedersen P S
University Department of Pediatrics, Rigshopitalet, Copenhagen, Denmark.
Acta Physiol Scand. 1990 Mar;138(3):359-68. doi: 10.1111/j.1748-1716.1990.tb08858.x.
Human sweat duct cells in primary culture were investigated by voltage-clamp technique. Stimulation with the muscarinic agonist, metacholine (MCh), produced an abrupt transient rise followed by sustained regular oscillations in the transepithelial short-circuit current (Iscc), which in these cells is carried by a mucosal amiloride-sensitive Na+ influx, secondary to a Ca2(+)-activated, voltage-dependent, large K+ shunt across the serosal membrane. The time of latency, the initial transient phase, and the sustained oscillating phase of the MCh-induced Iscc response were demonstrated to be differently affected by changes in temperature, agonist concentration and external Ca2+ supply. From these results a model is proposed for the MCh-induced signal transduction in cultured sweat duct cells, involving a primary intracellular oscillatory Ca2+ mobilization, activated by IPP, sustained by a temperature-regulated external Ca2+ supply, and counter-regulated by cytosolic Ca2+.
采用电压钳技术对原代培养的人汗腺导管细胞进行了研究。用毒蕈碱激动剂乙酰甲胆碱（MCh）刺激后，跨上皮短路电流（Iscc）出现突然的瞬时升高，随后是持续的规则振荡，在这些细胞中，该电流由黏膜阿米洛利敏感的Na +内流携带，继发于Ca2（+）激活的、电压依赖性的、穿过浆膜的大K +分流。结果表明，MCh诱导的Iscc反应的潜伏期、初始瞬态阶段和持续振荡阶段受温度、激动剂浓度和细胞外Ca2 +供应变化的影响不同。根据这些结果，提出了一个在培养的汗腺导管细胞中MCh诱导的信号转导模型，该模型涉及由IPP激活的初级细胞内振荡性Ca2 +动员，由温度调节的细胞外Ca2 +供应维持，并由胞质Ca2 +进行反向调节。
