Interaction of hydration and subfornical organ lesions in sodium-depletion induced salt appetite.
The authors tested whether the level of hydration after furosemide diuresis and 22 hr of sodium depletion affects the amount of water or 0.3 M NaCl solution consumed by rats with intact brains or with lesions of the subfornical organ (SFO). Rats received 2 (underhydrated) or 10 (euhydrated) ml/kg water by gavage as the only fluid input 2, 4, and 20 hr after 10 mg/kg furosemide. These hydration treatments had little or no effect on the amount of saline consumed in 2 hr by intact rats. SFO lesions reduced water intake regardless of hydration condition. Euhydrated, SFO-lesioned rats drank a normal amount of saline, but underhydrated, lesioned rats drank less saline than any other group. Thus, euhydration may facilitate salt appetite in SFO-lesioned rats, and the deficits in salt appetite noted in SFO-lesioned rats may result from deficits in water ingestion rather than from a destruction of angiotensin II receptor sites that directly provoke salt appetite.
Starbuck
E M
EM
Department of Psychology, University of Washington, Seattle 98195-1525, USA.
Lane
J R
JR
Fitts
D A
DA
D000818:Animals; D001066:Appetite / Q000502:physiology*; D001931:Brain Mapping; D006706:Homeostasis / Q000502:physiology; D008297:Male; D009042:Motivation; D051381:Rats; D012462:Saline Solution, Hypertonic / Q000008:administration & dosage*; D013356:Subfornical Organ / Q000502:physiology*; D014868:Water Deprivation / Q000502:physiology*; D014882:Water-Electrolyte Balance / Q000502:physiology*
D012462:Saline Solution, Hypertonic