A method for measuring the oxygen consumption of intact cell monolayers

Abstract

This report describes an open-air method for measuring the O2 consumption (Q˙o 2) of intact monolayers of cultured cells. This method is based on Fick's second law of diffusion. It requires only a micromanipulator and a miniature O2 electrode to measure the[Formula: see text] gradient in the culture medium in the well. It was compared with the conventional oxygraph chamber method. Both methods gave the same value forQ˙o 2 in freshly isolated rat type II cells: 166 ± 15.3 nmol ⋅ h−1 ⋅ 106cells−1 for the open-air method and 151 ± 11.6 nmol ⋅ h−1 ⋅ 106cells−1 for the oxygraph chamber method ( n = 11 experiments). But the open-air method gave significantly larger values for Q˙o 2 in cells cultured for 2 days (236 ± 8.8 nmol ⋅ h−1 ⋅ 106cells−1) than the oxygraph method (71 ± 15.2 nmol ⋅ h−1 ⋅ 106cells−1; P < 0.001; n = 12 experiments). This suggests that the way cells are detached from their substratum to be placed in the oxygraph chamber affects theirQ˙o 2. The open-air method may be useful for studies on the metabolic properties of monolayers because the cells do not risk being damaged.