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Intracerebroventricular injection of renin in the neonatal rat reveals a precocious sodium appetite that is dissociated from renin‐aroused thirst
Author(s) -
Leshem Micah,
Canho Sonia Del,
Epstein Alan N.
Publication year - 1994
Publication title -
developmental psychobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 93
eISSN - 1098-2302
pISSN - 0012-1630
DOI - 10.1002/dev.420270305
Subject(s) - thirst , appetite , endocrinology , renin–angiotensin system , medicine , sodium , sed , chemistry , stimulation , blood pressure , organic chemistry
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.© 1994 John Wiley & Sons, Inc.