Florey Neuroscience Institutes of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia.
Am J Physiol Regul Integr Comp Physiol. 2013 Jun 15;304(12):R1149-60. doi: 10.1152/ajpregu.00481.2012. Epub 2013 Apr 17.
Most ingested sodium is contained in food. The aim was to investigate whether sodium depletion, dehydration, or DOCA alters intakes of salted and unsalted foods by rats given choices of two foods: salted (0.2-0.5% Na) and unsalted food containing either similar or different other dietary components. Diuretic-induced (furosemide or acetazolamide, two treatments on successive days) sodium depletion always caused pronounced falls in intake of unsalted food within 24 h, continuing at least another 2 days (e.g., 20.9 ± 1.6 pretreatment to 14.8 ± 1.2, 10.6 ± 1.5, and 14.3 ± 1.3 g/day for 3 days of depletion). Intake and preference for salted food increased after 24-72 h (e.g., 6.5 ± 1.2 pretreatment to 7.1 ± 1.1, 16.4 ± 2.3, and 17.0 ± 1.5 g/day at 1, 2, and 3 days of depletion). Valsartan (10 mg/day) blocked the increased intake of salted food but not the reduced intake of unsalted food. DOCA (2 mg/day) caused equivalent increase and decrease in intakes of salted and unsalted food, respectively. Water-deprived rats reduced intake (e.g., 14.2 ± 3.1 to 3.2 ± 2.0 g/day) of and preference for salted food (e.g., 56 ± 13% to 21 ± 11%) after 2 days of dehydration but did not consistently reduce intake of unsalted food. Total food ingested/day fell in both sodium-depleted and dehydrated rats. Rats regulate intakes of different foods to balance sodium needs, osmoregulatory homeostasis, and energy requirements. Reduced appetite for unsalted food may be a homeostatic response to sodium depletion, which together with subsequent generation of appetite for salted food, drives animals to ingest sodium-containing food, thereby restoring sodium balance.
大多数摄入的钠存在于食物中。本研究旨在探讨钠耗竭、脱水或 DOCA 是否会改变大鼠对两种食物的摄入：加盐（0.2-0.5% Na）和不加盐的食物，后者含有相似或不同的其他膳食成分。利尿剂诱导的（呋塞米或乙酰唑胺，两种处理方式连续两天）钠耗竭总是在 24 小时内导致不加盐食物的摄入量明显下降，至少持续另外 2 天（例如，20.9 ± 1.6 预处理至 14.8 ± 1.2、10.6 ± 1.5 和 14.3 ± 1.3 g/天，连续 3 天耗竭）。加盐食物的摄入和偏好在 24-72 小时后增加（例如，6.5 ± 1.2 预处理至 7.1 ± 1.1、16.4 ± 2.3 和 17.0 ± 1.5 g/天，在耗竭的第 1、2 和 3 天）。缬沙坦（10 mg/天）阻断了加盐食物摄入量的增加，但没有阻断不加盐食物摄入量的减少。DOCA（2 mg/天）分别导致加盐和不加盐食物摄入量的同等增加和减少。缺水的大鼠在 2 天脱水后减少加盐食物（例如，14.2 ± 3.1 至 3.2 ± 2.0 g/天）和加盐食物的偏好（例如，56 ± 13%至 21 ± 11%），但并不一致地减少不加盐食物的摄入。两种耗竭大鼠的每日总食物摄入量均下降。大鼠调节不同食物的摄入量以平衡钠需求、渗透压稳态和能量需求。对不加盐食物的食欲下降可能是对钠耗竭的一种稳态反应，随后对加盐食物的食欲增加，促使动物摄入含钠食物，从而恢复钠平衡。
