| Sumario: | 1. Toads maintained in fresh water and submitted periodically to careful manipulation showed higher urine production than water uptake, and body weight loss. 2. After complete removal of the ADH (antidiuretic hormone) secreting system, animals developed polyuria without changes in water uptake, and extreme body weight loss. 3. Small lesions of the midbrain midtegmental area caused a stable and copious intake of water across the skin, polyuria, negative water balance and body weight loss. A similar but temporary increase in water uptake, combined with oliguria, and a gain of body weight was observed during the reversible coma induced by blocking the same region of the midbrain with a microinjection of 3 M KCl, in both normal and hypophysectomized toads. 4. General anesthesia with urethan reproduced closely the picture of polyuria and high water intake due to midbrain lesion in normal as well as in hypophysectomized animals. 5. We postulate an extrahypophyseal nervous mechanism that controls the influx of water across the skin and urine production in the toad, with its focus in the midbrain midtegmental area. © 1982 Springer-Verlag.
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