Spontaneous ultraweak light emission from respiring spinach leaf mitochondria

Author: Èva Hideg 1, Masaki Kobayashi1, Humio Inaba 1, 2
a Biophoton Project, Research Development Corporation of Japan (JRDC), Sendai Japan b Research Institute of Electrical Communication, Tohoku University, Sendai Japan
Conference/Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics
Date published: 1991 Dec 3
Other: Volume ID: 1098 , Pages: 27-31 , Special Notes: doi:10.1016/0005-2728(91)90005-9 , Word Count: 141

Mitochondria isolated from spinach leaves showed spontaneous ultraweak light emission depending on the respiration with succinate. This emission was sensitive to respiratory inhibitors, such as, antimycin-A and potassium cyanide. Mitochondrial photoemission was inhibited by azide and salicylhyrdoxamic acid and enhanced in the presence of 1,4-diazabicyclo[2,2,2]-octane (DABCO), implying a role of singlet oxygen in the process. Ultraweak light emission and singlet oxygen production, the latter determined spectroscopically in experiments parallel to light measurements, exhibited similar changes upon various chemical treatments. The emission spectrum of ultraweak light closely resembles that of chemiluminescence from an in vitro (linoleic acid + peroxidase) lipid peroxidation. We suggest that the observed phenomenon is a result of the peroxidation of mitochondrial membrane lipids initiated by the activity of the respiratory electron transport, probably at the cytochrome c site.

Ultraweak light emission; Emission spectrum; Lipid peroxidation; Mitochondrion; Spinach