Plasma amino acid levels in cataract.

Fasting plasma amino-acid profiles were determined in 32 subjects with either cataractous lenses (24 subjects) or normal lenses (eight subjects). The findings were compared with established laboratory normal values. The amino-acid levels of all subjects with normal lenses were within the normal range for the subjects' age groups. In contrast, subjects with presenile or senile cataracts had markedly elevated levels of glutamine, with similar elevations of alanine in presenile cataract and of histidine in senile cataract. To the best of our knowledge, this is the first report of such a plasma amino-acid pattern in subjects with presenile and senile cataracts.