Distinction between urinary acids originating from nutrition and those produced in the human body

Production of antiserum for sensitive enzyme-linked immunosorbent assay of 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid by chemiluminescence

To obtain a specific antiserum for use in enzyme-linked immunosorbent assay (ELISA) of 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF), we prepared a hapten-carrier conjugate in which the CMPF hapten was linked to a carrier protein through the 5-(1-hydrazopropyl) group. The antisera raised against this antigen in guinea pigs had excellent specificity for CMPF, showing little cross-reactivity with closely related compounds and no significant cross-reactivities with other furan compounds. The results indicated that a specific antiserum to CMPF could be produced by an antigen whose CMPF moiety is linked to a carrier protein through a position remote from the inherent functional groups. A standard curve of CMPF by ELISA using a chemiluminescence system showed a high sensitivity and a linearity in the range of 5-100 ng/mL.

Changes in the excretion of organic acids in human urine after physical exertion

The excretion of some acids in urine is subject to a circadian rhythm, if diversified nutrition is offered to the body sufficiently. The effect of physical exertion upon the excretion rates of acids in urine is very similar to that of a zero diet, resulting in an increase of final degradation products and a decrease of metabolic intermediates.