Stricker Edward M, Hoffmann Myriam L, Riccardi Christiana J, Smith James C
Department of Neuroscience, University of Pittsburgh, 446 Crawford Hall, Pittsburgh, PA 15260, USA.
Physiol Behav. 2003 Sep;79(4-5):621-31. doi: 10.1016/s0031-9384(03)00172-0.
To determine the temporal relation between the ingestion of dry food containing 8% NaCl and the increased daily consumption of water that occurs when rats eat this diet, rats were placed in specially designed cages linked to microprocessors that allowed the continuous monitoring of food and water ingestion. The increase in water intake was found to result from increases both in number and size of individual drinking bouts. Approximately 75% of the water intake was consumed in drinking bouts that occurred less than 5 min after feeding. Indeed, rats rarely consumed 8% NaCl diet without also drinking water in the same ingestive episode, and the volume of water they drank was proportional to the food intake in that episode. These and other observations suggest that ingestion of the high salt diet stimulated thirst rapidly. As such, they are consistent with previous reports that visceral osmoreceptors (or Na(+)-receptors) detect osmolytes passing through the gastrointestinal tract and provide an early stimulus of thirst in rats that precedes large increases in systemic plasma osmolality.
为了确定摄入含8%氯化钠的干粮与大鼠食用该饮食时每日饮水量增加之间的时间关系，将大鼠置于与微处理器相连的特殊设计笼子中，微处理器可连续监测食物和水的摄入量。发现饮水量增加是由于单次饮水次数和饮水量的增加所致。约75%的饮水量是在进食后不到5分钟的饮水过程中消耗的。实际上，大鼠很少在同一进食过程中只食用8%氯化钠饮食而不饮水，且它们的饮水量与该过程中的食物摄入量成正比。这些及其他观察结果表明，高盐饮食的摄入会迅速刺激口渴。因此，它们与之前的报道一致，即内脏渗透压感受器（或Na(+)受体）检测通过胃肠道的渗透溶质，并在大鼠全身血浆渗透压大幅升高之前提供早期口渴刺激。
