[Diurnal variations evidence of glomerular filtration in the rat (author's transl)].

Parallel variations in plasma and urine variations of endogenous urea and creatinine level in the rat during 4 consecutive 6-h-long periods permit to evidence urea and creatinine clearance diurnal variations with very significant increase in the 2 nightly periods. The signification of this very large nightly glomerular filtration increase is discussed.