钾通道阻滞剂和钾离子载体对异丙肾上腺素诱导的大鼠腮腺腺泡淀粉酶分泌的影响。
Effects of K+ channel blockers and K+ ionophore on isoprenaline-induced secretion of amylase from rat parotid acini.
作者信息
Murayama T, Miwa Y, Maeda S, Morisaki I, Saito K
机构信息
Department of Pharmacology, Osaka University, Faculty of Dentistry, Japan.
出版信息
Eur J Pharmacol. 1997 Mar 12;322(1):21-5. doi: 10.1016/s0014-2999(96)00990-9.
The involvement of K+ channels in regulating secretion of amylase from isolated rat parotid acini was studied in conjunction with beta-adrenoceptor function. It was observed that increasing the concentration of extracellular K- or adding K+ channel blockers enhanced the secretion of amylase. Among several K+ channel blockers, tetraethylammonium, apamin and charybdotoxin were effective to enhance secretion by 48, 69 and 84%, respectively. Glibenclamide was without effect. A low concentration of isoprenaline (10(-7) M) enhanced secretion by 154% and its simultaneous application with tetraethylammonium gave a synergistic effect, producing 371% stimulation. Combination of tetraethylammonium and a low concentration of carbachol (10(-6) M) did not give the synergistic effect. Isoprenaline at the concentration of 10(-6) M enhanced secretion by 313% and this was reduced to 116% by 10(-5) M valinomycin, a K+ ionophore. Valinomycin was without effect on carbachol (10(-5) M)-induced secretion. Somatostatin (10(-5) M) and morphine (10(-4) M) also reduced isoprenaline-induced secretion of amylase. These results suggested the regulation of Ca(2+)-activated K+ channels by isoprenaline in amylase secretory processes in parotid acini.
结合β - 肾上腺素能受体功能，研究了钾通道在调节离体大鼠腮腺腺泡淀粉酶分泌中的作用。观察到增加细胞外钾浓度或添加钾通道阻滞剂可增强淀粉酶的分泌。在几种钾通道阻滞剂中，四乙铵、蜂毒明肽和大蝎毒素分别能有效增强分泌，增幅为48%、69%和84%。格列本脲无效。低浓度异丙肾上腺素（10⁻⁷ M）可使分泌增加154%，其与四乙铵同时应用产生协同作用，刺激幅度达371%。四乙铵与低浓度卡巴胆碱（10⁻⁶ M）联合应用未产生协同作用。浓度为10⁻⁶ M的异丙肾上腺素可使分泌增加313%，而10⁻⁵ M缬氨霉素（一种钾离子载体）可使其降至116%。缬氨霉素对卡巴胆碱（10⁻⁵ M）诱导的分泌无影响。生长抑素（10⁻⁵ M）和吗啡（10⁻⁴ M）也可减少异丙肾上腺素诱导的淀粉酶分泌。这些结果提示在腮腺腺泡淀粉酶分泌过程中，异丙肾上腺素对钙激活钾通道具有调节作用。
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