Novak I, Young J A
Pflugers Arch. 1986 Dec;407(6):649-56. doi: 10.1007/BF00582647.
Cholinergically stimulated Cl and HCO3 transport in perfused rabbit mandibular glands has been studied with extracellular anion substitution and administration of transport inhibitors. In glands perfused with HCO3-free solutions, replacement of Cl with other anions supported secretion in the following sequence: Br = greater than Cl greater than I = greater than NO3 greater than isethionate. Furosemide, 1.0 and 0.1 mmol/l, inhibited Cl-supported secretion by 97-99% and 70-78%, respectively. SITS, 0.1 mmol/l, had no effect and amiloride, 1.0 mmol/l, caused a 55-65% inhibition. Addition of SITS to amiloride-treated glands produced no further effect. In glands perfused with Cl-free solutions, but containing 25 mM HCO3, amiloride, 1.0 mmol/l, inhibited secretion by 95% and methazolamide, 0.1 mmol/l, by 55%. In glands perfused with solutions containing both HCO3 and Cl, furosemide had smaller effects than in glands perfused with solutions containing only Cl - a dose of 1.0 mmol/l inhibited 60% of the initial fast phase of secretion, and 90% of the later plateau phase, while a dose of 0.1 mmol/l inhibited 30% of the initial phase, but had no effect on the plateau. SITS, 0.1 mmol/l, actually stimulated secretion by about 30%, but when infused in addition to furosemide (0.1 mmol/l), it inhibited by about 20%. Amiloride (1.0 mmol/l) caused no inhibition. The results suggest that there are at least three distinct carriers in the rabbit mandibular gland. One is a furosemide-sensitive Na-coupled Cl (probably Na-K-2Cl) symport, responsible for the bulk of normal secretion. The others are an amiloride-sensitive Na-H antiport and a SITS-sensitive Cl-HCO3 antiport.
利用细胞外阴离子替代和转运抑制剂给药的方法，对灌注兔下颌下腺中胆碱能刺激的氯离子（Cl）和碳酸氢根离子（HCO₃）转运进行了研究。在用无HCO₃溶液灌注的腺体中，用其他阴离子替代Cl支持分泌的顺序如下：溴离子（Br）＞氯离子（Cl）＞碘离子（I）＞硝酸根离子（NO₃）＞羟乙基磺酸根离子（isethionate）。1.0 mmol/l和0.1 mmol/l的呋塞米分别使Cl支持的分泌抑制97 - 99%和70 - 78%。0.1 mmol/l的4-乙酰氨基-4'-异硫氰酸芪-2,2'-二磺酸（SITS）没有作用，1.0 mmol/l的阿米洛利导致55 - 65%的抑制。在经阿米洛利处理的腺体中加入SITS没有进一步的作用。在用无Cl溶液灌注但含有25 mM HCO₃的腺体中，1.0 mmol/l的阿米洛利使分泌抑制95%，0.1 mmol/l的甲醋唑胺使分泌抑制55%。在用含有HCO₃和Cl的溶液灌注的腺体中，呋塞米的作用比在用仅含Cl的溶液灌注的腺体中小——1.0 mmol/l的剂量抑制分泌初始快速期的60%和后期平台期的90%，而0.1 mmol/l的剂量抑制初始期的30%，但对平台期没有作用。0.1 mmol/l的SITS实际上使分泌刺激约30%，但当与0.1 mmol/l的呋塞米一起注入时，它抑制约20%。1.0 mmol/l的阿米洛利没有引起抑制作用。结果表明，兔下颌下腺中至少存在三种不同的载体。一种是对呋塞米敏感的钠偶联Cl（可能是Na-K-2Cl）同向转运体，负责大部分正常分泌。其他的是对阿米洛利敏感的钠-氢反向转运体和对SITS敏感的Cl-HCO₃反向转运体。
