Stricker E M
Behav Neurosci. 1983 Oct;97(5):725-37. doi: 10.1037//0735-7044.97.5.725.
Recent experiments indicated that rats usually develop sodium appetite 5 hr after subcutaneous injection of polyethylene glycol (PEG) solution. However, sodium appetite appeared within 30 to 60 min if the rats had been maintained on sodium-deficient diet instead of Purina chow for 2-4 days previously. Elevated levels of aldosterone paralleled the appearance of NaCl consumption in both circumstances. In the present experiments, sodium appetite was no longer potentiated by pretreatment maintenance on sodium-deficient diet when the hypersecretion of aldosterone after PEG administration was prevented by prior hypophysectomy. Conversely, sodium appetite was enhanced in PEG-treated rats when angiotensin II (AII) was produced in unusually large amounts in the brain, owing to the systemic administration of captopril. This latter effect occurred even when drinking water was withheld and plasma sodium concentrations were markedly elevated. These and other findings raise the possibility that the normal secretion of aldosterone in rats after PEG treatment might permit physiological amounts of AII to be effective in stimulating sodium appetite. Such actions would complement the accepted physiological role of the renin-angiotension-aldosterone system in the maintenance of blood pressure and sodium balance.
最近的实验表明，大鼠皮下注射聚乙二醇（PEG）溶液5小时后通常会产生钠食欲。然而，如果大鼠此前2 - 4天一直食用缺钠饮食而非普瑞纳饲料，那么钠食欲会在30至60分钟内出现。在这两种情况下，醛固酮水平的升高与氯化钠摄入量的增加同时出现。在本实验中，当通过预先垂体切除来阻止PEG给药后醛固酮的过度分泌时，缺钠饮食预处理就不再增强钠食欲。相反，由于全身性给予卡托普利，导致大脑中异常大量产生血管紧张素II（AII），PEG处理的大鼠的钠食欲增强。即使禁水且血浆钠浓度显著升高，后一种效应仍会出现。这些以及其他发现增加了一种可能性，即PEG处理后大鼠醛固酮的正常分泌可能使生理量的AII有效刺激钠食欲。这样的作用将补充肾素 - 血管紧张素 - 醛固酮系统在维持血压和钠平衡方面公认的生理作用。
