Talk:Uncoupler

Which meaning of 'uncoupling'?

I was getting increasingly worried about the fact that students have difficulties to understanding uncoupling or coupling in bioenergetics and mitochondrial physiology. In this context we should realize that conventional terminology is not particularly helpful. In fact, the meaning of 'uncoupling' (in the current literature and bioenergetics textbooks) must usually be deduced from the specific context, but this can be achieved only after the concept and context are clear. Are intact mitochondria partially uncoupled, or partially coupled?

Exaggerating, we may be used to phrases such as:

• Uncoupling was studied in stressed cells by measurement of coupled respiration, evaluation of uncoupled respiration after inhibition with oligomycin, and FCCP titration to quantify uncoupled respiration.

Perhaps this is intuitively more clear:

• Dyscoupling was studied in stressed cells by measurement of partially coupled ROUTINE respiration, evaluation of LEAK respiration after inhibition with oligomycin, and FCCP titration to quantify ETS capacity in the non-coupled state.

I am even still worried about the different meanings of (1) intrinsic and (2) experimental uncoupling, but have not found a solution. The distinction between dyscoupling versus intrinsic (adaptive?) uncoupling is a fundamental challenge, not of terminology, but of understanding the physiological functions of intrinsic uncoupling.

--Gnaiger Erich 09:01, 31 May 2011 (CEST)

Uncoupler titrations cause small jumps in oxygen concentration

• Q: When adding FCCP, the O2 concentration rises a bit. Does this mean that the cells are consuming or releasing oxygen?
• A: You add FCCP dissolved in ethanol. Ethanol has a high oxygen solubility, hence your titration is the cause of the increase in oxygen concentration.