Pyruvate and glucose uptake by mouse ova and preimplantation embryos

TLDR

A method was devised to measure nutrient uptake in small numbers of mouse ova and preimplantation embryos. Embryos were incubated in small volumes on siliconized slides under mineral oil, and serial 4 nl samples were collected every 30 min for 3 h and assayed for glucose and pyruvate by ultramicrofluorometry. Pyruvate uptake surpassed glucose uptake in unfertilized and fertilized ova and early embryos, but glucose became predominant at the blastocyst stage, and a carrier‑mediated component likely contributed to pyruvate uptake in unfertilized ova. Summary.

Abstract

Summary. A method has been devised to measure the uptake of nutrients by small numbers of mouse ova and preimplantation embryos. The 1–5 embryos were incubated as a group at 37°C in a small volume (at least 20 nl/embryo) of culture medium on siliconized microscope slides under mineral oil. Serial 4 nl samples were taken at 30min intervals for 3 h and assayed for their content of glucose and pyruvate using an ultramicrofluorometric technique. Pyruvate uptake exceeded that of glucose in unfertilized and fertilized ova and in the developmental stages up to the blastocyst, when glucose became the predominant substrate. A component of the uptake of pyruvate by unfertilized ova was probably mediated by a carrier.