Parallel effects of DOCA on salt appetite, thirst, and blood pressure in sheep

Salt appetite was quantified in sheep by measuring the relative amounts of high-salt (266 meq/kg) and low-salt (6 meq/kg) pelleted alfalfa that they ate. Given a choice of these two foods, normal sheep ate twice as much low-salt as high-salt pellets. Following DOCA administration the sheep rapidly developed an increased salt appetite, and after 10 days they ate approximately three times as much high-salt as low-salt pellets. Their choice rapidly reverted to control values after the end of the DOCA treatment. The changes in salt appetite were accompanied by changes in thirst and mean arterial pressure. We hypothesize that these effects of DOCA reflect changes that parallel those this mineralocorticoid causes in the hypothalamic regulatory centers for salt appetite, thirst, and blood pressure.