摘要：

1. 1. Brush border membrane vesicles (BBMV) were prepared from midguts of Pieris brassicae larvae by Mg/EGTA precipitation and differential centrifugation. 2. 2. Their morphology, polypeptide composition, and marker enzyme enrichment was similar to BBMV from other larval lepidopteran midguts. 3. 3. In the presence of an inwardly directed KSCN gradient, these BBMV transiently accumulated alanine, phenylalanine, histidine, lysine, or gultamic acid. 4. 4. Initial uptake rates for neutral and basic amino acids were similar in the presence of either a potassium or a sodium gradient. 5. 5. Initial uptake of glutamic acid was much more efficient in the presence of a sodium gradient.

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