Renal clearance definition

Dent s classification is the basis of most classifications of abnormal types of amino aciduria. He divides the pathological conditions into three categories (D9) (A) Overflow amino aciduriain which the blood level of the amino acid concerned is definitely raised above normal [example Section 4.2.1.L (a)] (B) Renal amino aciduria, in which case the blood level is either normal or below normal, and yet the urinary excretion is above normal [tubular reabsorption deficiency example Section 4.2.I.I. (e)] (C) No threshold amino aciduria, in which Dent attributes the condition to an extrarenal disturbance of the metabolism of an amino acid with a high blood clearance, and in which, on account of this latter circumstance, the corresponding blood level may stay normal or is hardly increased. 

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