Water adulteration with citric acid: effects on drinking and responsivity to regulatory challenges.

Rats with permanent access to a water supply adulterated with citric acid (CA) displayed persistent reductions in fluid intake and fluid/food ratios; and at appropriate concentrations of CA, they also exhibited lowered body weights and drinking deficits after fluid deprivation and after hypertonic NaCl injections. Unlike rats in previous investigations that were forced to consume quinine adulterated water, CA drinkers exhibited less disruption in their ingestive behavior following regulatory challenges, diminished short-term but greater long-term abilities in responding to hypovolemia, and an ability to increase fluid intake after fluid deprivation plus hypertonic NaCl. These data reveal that substances which degrade the taste quality of water do not exert a unitary influence on fluid intake, and they further underscore the complexity of ecological factors involved in controlling drinking behavior.