[Urea feeding of sheep on a diet rich in proteins: effects on urinary secretion]

Ten ewes kept on a high protein level diet were fed water solutions of urea (0.25 g/kg). Blood urea, urine volume and renal urea excretion were determined thereafter. A long lasting increment of blood urea level was observed as well as an increased urine volume with a lowered urinary osmotic pressure. Moreover, urea clearance was significantly decreased in spite of the increased amount of urea excreted by the kidney. A negative correlation between urea clearance and blood urea level could be demonstrated when the latter was higher than 0.5 g/l.