Influence of vasopressin and calcium on electrolyte transport across isolated colonic mucosa of the rat.
Influence of vasopressin and calcium on electrolyte transport across isolated colonic mucosa of the rat.
复制标题
加压素和钙对大鼠离体结肠粘膜电解质转运的影响。
DOI：
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发表时间：
1983
期刊：
影响因子：
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通讯作者：
W. Rummel
中科院分区：
文献类型：
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作者：
R. Bridges;G. Nell;W. Rummel
加压素增强了大鼠降结肠外翻囊对水和Na+的吸收，但对升结肠的吸收没有影响。加压素可剂量依赖性地降低降结肠的短路电流（Isc）和开路电位差（p.d.）。 Isc 和 p.d.升结肠的分布不被加压素改变。在结肠中，Isc 和 p.d 下降。在 1 微单位时显着。加压素/ml，达到最大值1μ/ml。普萘洛尔和酚妥拉明或纳洛酮不会改变 Isc 和 p.d 的降低。至次最大剂量的加压素。加压素增加了 Na+ 和 Cl- 的粘膜到浆膜的通量，并减少了 Cl- 穿过短路降结肠的浆膜到粘膜的通量。因此，这些变化增加了 Na+ 和 Cl- 的净通量。降结肠匀浆中的腺苷酸环化酶活性不被加压素改变。从浆膜浴溶液中去除 Ca2+ 可逆地降低 Isc 和 p.d。结肠中 Na+ 和 Cl- 吸收的增加以与加压素类似的方式下降。结果表明，加压素对降结肠的影响可能是由于细胞内Ca2+活性降低所致。
Vasopressin enhanced the absorption of water and Na+ across everted sacs of rat colon descendens but had no effect on absorption across the colon ascendens. The short‐circuit current (Isc) and open‐circuit potential difference (p.d.) across the colon descendens were dose‐dependently decreased by vasopressin. Isc and p.d. across the colon ascendens were not altered by vasopressin. In the colon descendens the decrease in Isc and p.d. was significant at 1 microu. vasopressin/ml and reached a maximum at 1 mu./ml. Propranolol and phentolamine or naloxone did not alter the decrease in Isc and p.d. to a submaximal dose of vasopressin. Vasopressin increased the mucosal to serosal flux of Na+ and Cl‐ and decreased the serosal to mucosal flux of Cl‐ across short‐circuited colon descendens. Consequently these changes increased the net flux of Na+ and Cl‐. Adenylate cyclase activity in homogenates of the colon descendens was not altered by vasopressin. Omission of Ca2+ from the serosal bathing solution reversibly decreased Isc and p.d. and increased Na+ and Cl‐ absorption across the colon descendens in a similar way as did vasopressin. The results suggest that the effect of vasopressin on the colon descendens may be due to a decrease in intracellular Ca2+ activity.