Development of a noninvasive ultramicrofluorometric method for measuring net uptake of glutamine by single preimplantation mouse embryos

Abstract

A noninvasive ultramicrofluorometric method for measuring net uptake of glutamine by single preimplantation mouse embryos is described. A linear relationship was found between fluorescence intensity of NADH produced and glutamine concentration (R2 = 0.985). Single embryos were placed in 20 nl drops of medium containing 0.5 mM glutamine, and the medium was sampled after 2 hr incubation at 37°C. Changes in net glutamine uptake were determined in one‐cell, two‐cell, and eight‐cell embryos and blastocysts incubated in medium containing no energy substrates (glucose, pyruvate, and lactate). The median glutamine uptake increased significantly from 0.480 and 0.270 pmoles/embryo/2 hr at the one‐cell..