Pteroylglutamic Acid Malabsorption in

Pteroylglutamic acid (PGA) absorption days. A statistically significant difference was assessed in ten untreated tropical in PGA absorption between TS and consprue (TS) and eight control subjects trol subjects was obtained only when gluutilizing a marker perfusion technique. cose was present in the perfusate. Thus, Physiologic concentrations of the vitamin unequivocal malabsorption of PGA is (25 ng/ml) dissolved in iso-osmotic soludemonstrable in all subjects with TS when tions containing either mannitol or glucose more refined techniques than the ones apat a concentration of 55.6 mM were perplied heretofore are utilized. fused on each subject on two consecutive F OLATE DEFICIENCY IS almost invariably present in subjects with tropical sprue (TS) studied in Puerto Rico. Although the most important single factor responsible for such deficiency is probably folate malabsorption, the resuIts obtained utilizing the conventional techniques available for the assessment ofabsorption ofthis vitamin have yielded erratic results.’ The development of more sensitive marker perfusion techniques2 have allowed us to study the transport of pteroylglutamic acid (PGA) across the jejunum of subjects with this syndrome. The results reported herein demonstrate PGA malabsorption in all the TS subjects studied when physiologic concentrations of the vitamin3 were perfused with a glucose-containing solution. MATERIALS AND METHODS