Leshem M, Del Canho S, Epstein A N
Department of Psychology, University of Haifa, Israel.
Dev Psychobiol. 1994 Apr;27(3):185-93. doi: 10.1002/dev.420270305.
Previous research on the ontogeny of sodium appetite in the rat has shown that sodium deficit first engenders sodium intake at 12 days of age, whereas direct stimulation of the brain renin--angiotensin system by intracranial injection of renin increases intake of NaCl solution as early as 3 days postnatally. Similar activation of brain angiotensin also increases thirst, so that the specificity of the precocious sodium intake remains undetermined. In this article we report experiments that dissociate neonatal renin-evoked sodium appetite and thirst, and establish the specificity of the appetite. Our findings confirm that sodium appetite can first be discerned at 3 days of age, and show that it rapidly develops until 12 days of age. During this developmental window, renin-evoked sodium appetite is dissociated from thirst because (a) NaCl is preferred to water, (b) the appetite develops faster than thirst, and (c) 3-day-old renin-stimulated pups will avidly lick dry NaCl. These results show that activation of brain angiotensin in the 3-day-old rat pup evokes a precocious and specific sodium appetite.
先前对大鼠钠食欲个体发生的研究表明，钠缺乏在12日龄时首次引发钠摄入，而通过颅内注射肾素直接刺激脑肾素 - 血管紧张素系统早在出生后3天就会增加氯化钠溶液的摄入量。脑内血管紧张素的类似激活也会增加口渴感，因此早熟钠摄入的特异性仍未确定。在本文中，我们报告了一些实验，这些实验区分了新生大鼠肾素诱发的钠食欲和口渴，并确定了这种食欲的特异性。我们的研究结果证实，钠食欲在3日龄时首次可被察觉，并表明它在12日龄前迅速发展。在这个发育窗口期，肾素诱发的钠食欲与口渴是分开的，因为（a）比起水，幼鼠更偏好氯化钠；（b）这种食欲比口渴发展得更快；（c）3日龄经肾素刺激的幼鼠会热切地舔舐干燥的氯化钠。这些结果表明，3日龄大鼠幼崽脑内血管紧张素的激活会引发早熟且特异的钠食欲。
