INFANTS IN TRINIDAD EXCRETE MORE 5-L-OXOPROLINE (L-PYROGLUTAMIC ACID)IN URINE THAN INFANTS IN ENGLAND - AN ENVIRONMENTAL NOT ETHNIC DIFFERENCE

The demand for glycine to satisfy normal growth during early life is c onsiderable and most has to be made endogenously. The extent to which adequate glycine is available can be assessed by measuring the urinary excretion of 5-L-oxoproline. The excretion of 5-L-oxoproline at 6 wee ks of age for infants in Trinidad of African, Indian or mixed parentag e (398 mu mol/mmol creatinine) was significantly greater than for infa nts born in England of Caucasian parentage (194 mu mol/mmol creatinine ). There was no relationship between 5-L-oxoproline excretion and eith er sex or pattern of feeding. There were significant inverse relations hips between 5-L-oxoproline/creatinine and birth weight, and head circ umference either at birth or 6 weeks of age, suggesting that limited a vailability of glycine is associated with poorer growth before and aft er birth. For a group of infants born in England of Indian parentage, excretion of 5-L-oxoproline (155 mu mol/mmol creatinine) was not diffe rent to infants of Caucasian parentage, but significantly less than in fants born in Trinidad. The demonstration that 5-L-oxoproline/creatini ne was similar in infants born in England, regardless of parentage, sh ows that the differences between England and Trinidad are related to e nvironment and are unlikely to be accounted for by genetic differences or ethnicity.