Abrupt glucose and oxygen consumption, termed respiratory burst, is known to occur and is associated with the formation of several oxygen containing compounds via the activation of nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase ( Forman and Torres, 2002). Phagocytic cells, such as neutrophils and monocytes, produce reactive oxygen species (ROS) during phagocytosis ( Forman and Torres, 2002). Living organisms bear defense mechanisms in which immune cells, such as neutrophils and monocytes, play pivotal roles in responding to and killing foreign bodies that invade the living system ( Forman and Torres, 2002 Halliwell and Gutteridge, 2007).
SECM imaging is thus claimed to be a highly sensitive and appropriate technique compared to other existing techniques available for evaluating oxidative stress in human cells, making it potentially useful for widespread applications in biomedical research and clinical trials. The results obtained show higher consumption of oxygen in cells undergoing respiratory burst. In addition, the quantitative evaluation of oxygen consumption in THP-1 cells was performed using a Z-scan. Two-dimensional respiratory activity imaging was performed using XY-scan. SECM imaging composed of a microelectrode was used to compare oxygen consumption between normal cellular respiration and during respiratory burst in THP-1 cells. The respiratory burst was measured in a human monocytic cell line (THP-1 cells) derived from an acute monocytic leukemia patient under the effect of the exogenous addition of phorbol 12-myristate 13-acetate, which acts as a differentiation inducer. In the current study, we attempt to evaluate the respiratory burst by monitoring the rapid consumption of oxygen by using scanning electrochemical microscopy (SECM) imaging. Among the various ROS, the superoxide anion radical is known to be primarily produced by nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase. Phagocytic cells, such as neutrophils and monocytes, consume oxygen and generate reactive oxygen species (ROS) in response to external stimuli.
4Graduate School of Environmental Studies, School of Engineering, Advanced Institute for Materials Research, Tohoku University, Sendai, Japan.3Hokuto Denko Corporation, Atsugi, Japan.2Biomedical Engineering Research Center, Tohoku Institute of Technology, Sendai, Japan.1Graduate Department of Environmental Information Engineering, Tohoku Institute of Technology, Sendai, Japan.
Hiroyuki Kikuchi 1 †, Ankush Prasad 2 †, Ryo Matsuoka 3, Shigeo Aoyagi 3, Tomokazu Matsue 4 and Shigenobu Kasai 1,2 *