Bastl C P, Binder H J, Hayslett J P
Am J Physiol. 1980 Mar;238(3):F181-6. doi: 10.1152/ajprenal.1980.238.3.F181.
Adrenalectomized rats were maintained on physiologic replacement doses of aldosterone or dexamethasone for 24 h after adrenalectomy. Net cation movement and transmural potential difference were determined during in vivo perfusion of the colon. Adrenalectomy without replacement steroids resulted in marked reduction of sodium and water absorption, potassium secretion, and transmural potential difference (PD). Aldosterone 10 microgram . 100 g body wt-1 . 24 h-1 significantly increased net potassium secretion above adrenalectomized levels but did not restore transport to control levels. Sodium and water absorption and transmural PD were not affected. Aldosterone 30 microgram . 100 g body wt-1 . 24 h-1 increased but did not restore net movement of sodium or potassium to control levels. In contrast to aldosterone, physiologic amounts of dexamethasone, 10 microgram . 100 g body wt-1 . 24 h-1, preserved normal electrolyte movement and electrical properties in adrenalectomized rats. In additional experiments the aldosterone antagonist spironolactone was administered for 3 days to rats with intact adrenal function. Net sodium absorption fell only 22% below control with insigificant decreases in potassium secretion and transmural PD. These data suggest that glucocorticoid hormones exert regulatory control of basal colonic fluid and electrolyte function.
肾上腺切除术后的大鼠在术后24小时内接受生理替代剂量的醛固酮或地塞米松维持治疗。在结肠的体内灌注过程中测定净阳离子运动和跨壁电位差。未补充类固醇的肾上腺切除术导致钠和水吸收、钾分泌以及跨壁电位差（PD）显著降低。醛固酮10微克·100克体重-1·24小时-1显著增加净钾分泌，使其高于肾上腺切除术后的水平，但未将转运恢复到对照水平。钠和水吸收以及跨壁PD未受影响。醛固酮30微克·100克体重-1·24小时-1增加了钠或钾的净运动，但未将其恢复到对照水平。与醛固酮相反，生理量的地塞米松，10微克·100克体重-1·24小时-1，在肾上腺切除术后的大鼠中保持了正常的电解质运动和电特性。在另外的实验中，给肾上腺功能正常的大鼠施用醛固酮拮抗剂螺内酯3天。净钠吸收仅比对照降低22%，钾分泌和跨壁PD的降低不显著。这些数据表明糖皮质激素对基础结肠液体和电解质功能发挥调节控制作用。
