Peripheral sympathetic neurons are thought to provide trophic regulatory signals for development of their target tissues. In the current study, the authors investigated the role of sympathetic tone in the functional development of the kidney in the rat, using intracisternal administration of 6-hydroxydopamine (6-OHDA). The treatment destroys central catecholaminergic pathways and permanently reduces sympathetic activity without ablating peripheral nerves terminals. Renal function was evaluated over the first two postnatal weeks, a period of rapid glomerular and tubular maturation, by tests of basal renal clearance, urinary concentrating ability in response to fluid deprivation, and the response to a vasopressin analog (DDAVP). Although basal renal clearance and the homeostatic response to fluid deprivation developed normally in the lesioned rats, the response to a maximally-effective dose of DDAVP was attenuated at the end of the second postnatal week, a time during which the normal response increased dramatically.