在无氯介质中，蛙胃分泌状态和静息状态下对分泌性钾离子、钠离子和碳酸氢根离子变化的电位差反应。
Potential difference responses to secretory K+, Na+ and HCO3- changes in secreting and resting states of frog stomach in Cl(-)-free media.
作者信息
Schwartz M, Carrasquer G, Rehm W S, Dinno M A
出版信息
Biochim Biophys Acta. 1987 Mar 12;897(3):445-52. doi: 10.1016/0005-2736(87)90441-x.
The effects of changes in secretory concentrations of K+, Na+ and HCO3- on transmucosal potential difference (PD) and resistance in Cl(-)-free (SO4(2-)) solutions were compared for secreting fundus and resting fundus of Rana pipiens. In the resting fundus experiments, histamine was not present in the nutrient solution and cimetidine was primarily used to obtain acid inhibition. Increase of K+ from 4 to 80 mM, decrease of Na+ from 156 to 15.6 mM and decrease of HCO3- from 25 to 5 mM gave, 10 min after the change, in the secreting fundus delta PD values of 39.7, -11.9 and 3.2 mV, respectively. In the resting fundus, 1.5 to 2 h after the addition of cimetidine, the same changes in secretory ion concentration gave delta PD values of 12.2, -5.6 and 1.5 mV, respectively. Replacement of cimetidine with SCN and without histamine yielded a delta PD somewhat lower than that in cimetidine, namely 9 mV for a K+ change from 4 to 80 mM. Subsequent addition of histamine with SCN present gave a delta PD of about 21 mV. The change in PD was attributed to histamine increasing the secretory membrane area, leading to an increase in K+ conductance. Another possibility is that histamine increases the K+ conductance per se.
比较了无 Cl⁻（SO₄²⁻）溶液中 K⁺、Na⁺和 HCO₃⁻分泌浓度变化对牛蛙分泌期胃底和静息期胃底跨黏膜电位差（PD）及电阻的影响。在静息期胃底实验中，营养液中不存在组胺，西咪替丁主要用于抑制胃酸分泌。在分泌期胃底，将 K⁺浓度从 4 mM 增加到 80 mM、Na⁺浓度从 156 mM 降低到 15.6 mM、HCO₃⁻浓度从 25 mM 降低到 5 mM，在变化 10 分钟后，PD 变化值分别为 39.7、-11.9 和 3.2 mV。在静息期胃底，加入西咪替丁 1.5 至 2 小时后，分泌离子浓度的相同变化产生的 PD 变化值分别为 12.2、-5.6 和 1.5 mV。用 SCN 替代西咪替丁且无组胺时，产生的 PD 变化略低于西咪替丁组，即 K⁺浓度从 4 mM 变为 80 mM 时为 9 mV。随后在有 SCN 存在的情况下加入组胺，产生的 PD 变化约为 21 mV。PD 的变化归因于组胺增加了分泌膜面积，导致 K⁺电导增加。另一种可能性是组胺本身增加了 K⁺电导。
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