Stricker E M, Gannon K S, Smith J C
Department of Behavioral Neuroscience, University of Pittsburgh, PA 15260.
Physiol Behav. 1992 Jan;51(1):27-37. doi: 10.1016/0031-9384(92)90200-l.
A detailed description of the increased intake of water and 0.5 M NaCl solution by rats after colloid-induced hypovolemia was obtained by measuring drinking activity every 6 s for 23 h. After an initial phase of largely single-bout water drinking that reflected hypovolemic thirst, there was a marked increase in saline drinking in multiple-bout episodes. This salt appetite developed while rats were volume depleted but persisted for hours even after the plasma volume deficits were repaired. Their drinking episodes then seemed to reflect osmoregulation, since cumulative intakes of water and saline were in appropriate proportions to produce a near-isotonic NaCl solution. Remarkably, rats concocted a 1% NaCl solution within 29% of the drinking episodes, by alternating intakes of water and saline every 30-90 s. This alternation was too rapid to allow significant absorption of ingested fluids from the intestines and changes in plasma osmolality, and thereby to permit central osmoreceptors to influence ongoing consumption. Instead, we propose that, in these episodes, rats are guided by gustatory receptors to obtain the desired NaCl in a palatable solution.
通过每6秒测量一次大鼠23小时的饮水活动，详细记录了胶体诱导的血容量减少后大鼠水和0.5M NaCl溶液摄入量的增加情况。在最初主要为单次饮水阶段反映了低血容量性口渴之后，多次饮水发作中的盐水饮用量显著增加。这种盐食欲在大鼠血容量减少时出现，但即使血浆容量不足得到纠正后仍持续数小时。然后它们的饮水发作似乎反映了渗透压调节，因为水和盐水的累积摄入量比例适当，可产生接近等渗的NaCl溶液。值得注意的是，大鼠在29%的饮水发作中通过每30 - 90秒交替摄入水和盐水，调配出了1%的NaCl溶液。这种交替速度太快，无法使摄入的液体从肠道大量吸收并导致血浆渗透压发生变化，从而使中枢渗透压感受器影响正在进行的饮水行为。相反，我们认为，在这些发作中，大鼠是受味觉感受器引导，以在可口的溶液中获取所需的NaCl。
