[Existence of an antidiuretic reflex in the sheep during food intake]

The effect of eating on glomerular filtration and urine flow was studied in the sheep. Glomerular filtration rate was reduced during eating but the effect disappeared when food was removed. Urine flow showed the same evolution but, after ingestion was stopped, it returned later than glomerular filtration to control values. During the early phases of feed ingestion, an anticipatory anti-diuretic reflex therefore exists. The anti-diuretic response is probably dependent on a simultaneous decrease in glomerular filtration. But the temporary delay between the recovery of glomerular filtration and urine flow after feed is removed suggests the existence of a second factor responsible for the lowered urine flow.