Regulation of NaCl solution intake and gastric emptying in adrenalectomized rats.
Regulation of NaCl solution intake and gastric emptying in adrenalectomized rats.
复制标题
肾上腺切除大鼠中氯化钠溶液摄入量和胃排空的调节。
DOI：
10.1016/j.physbeh.2007.06.007
复制
发表时间：
2007
影响因子：
2.9
通讯作者：
Stricker,EdwardM
中科院分区：
文献类型：
--
作者：
Bykowski,MichaelR;Smith,JamesC;Stricker,EdwardM
肾上腺切除（adrex）大鼠适应性地增加NaCl摄入量，以弥补由于醛固酮缺乏而导致的尿中Na+的不受控制的损失。在一段时间的NaCl剥夺后，他们大量摄入生理盐水，但在低钠血症修复之前停止饮用。本实验确定了系统前信号是否会抑制进一步的NaCl摄入，以及Na+的胃排空是否会根据摄入的NaCl溶液浓度进行调节。剥夺一夜后，adrex大鼠以最快的速度（~ 1.7 ml/min）摄入0.05 M和0.15 M NaCl，并以较慢但最快的速度（~ 1.1 ml/min）从胃中排空摄入的液体。当摄入0.30 M NaCl时，液体摄入仍然最快，但胃排空随浓度的增加而减慢，因此Na+排空与摄入0.15 M NaCl时（~ 0.13 meq/min）的排空相当。当摄入0.50 M NaCl时，Na+的摄入量成比例地减慢，因此Na+的摄入量与摄入0.30 M NaCl （~ 0.5 meq/min）时所观察到的Na+摄入量相当。从胃中排空的生理盐水浓度以及胃和小肠中摄入的液体量似乎都抑制了NaCl的摄入。当摄入0.50 M NaCl时，胃排空也成比例地减慢，就好像大鼠在调节Na+向小肠的输送一样。上述结果表明，adrex大鼠能够预先系统地检测摄入的NaCl溶液的体积和浓度，并整合这两个变量，从而调节Na+的摄入和胃排空速率。
Adrenalectomized (adrex) rats adaptively increase NaCl intake to compensate for the uncontrolled loss of Na+in urine due to the absence of aldosterone. After a period of NaCl deprivation, they ingest saline avidly but stop drinking before hyponatremia is repaired. The present experiments determined whether pre-systemic signals inhibit further NaCl intake, and whether gastric emptying of Na+is modulated according to the concentration of ingested NaCl solution. After overnight deprivation, adrex rats consumed 0.05 M and 0.15 M NaCl at a maximally fast rate (∼1.7 ml/min) and emptied ingested fluid from the stomach at a slower but maximally fast rate (∼1.1 ml/min). When 0.30 M NaCl was consumed instead, fluid intake still was maximally fast but gastric emptying slowed in proportion to concentration so that the emptying of Na+was comparable to that observed when 0.15 M NaCl was ingested (∼0.13 meq/min). When 0.50 M NaCl was consumed, intake slowed proportionately so that Na+consumption was comparable to that observed when 0.30 M NaCl was ingested (∼0.5 meq/min). NaCl intake appeared to be inhibited both by the concentration of saline emptied from the stomach and by the volume of ingested fluid in the stomach and small intestine. Gastric emptying also slowed proportionately when 0.50 M NaCl was consumed, as if the rats were regulating the delivery of Na+to the small intestine. These results suggest that adrex rats can detect the volume and concentration of ingested NaCl solution presystematically and integrate these two variables, and thereby modulate the rates of Na+intake and gastric emptying.