The uncoupling proteins: Some Physiological, others non-physiological; Some increase the body heat (temperature), others help decrease it.
(ATP synthesis is coupled to oxidative phosphorylation in mitochondria. If it is ‘uncoupled’, energy will be converted to heat instead of ATP.)
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Uncoupling protein (UCP):- It is located in the inner mitochondrial membrane. It uncouples the oxidative phosphorylation from ATP generation; thus, converting the energy into heat. It has the physiological role of maintaining body temperature during exposure to cold. UCP-1 (thermogenin) is found in the brown adipose tissue (BAT).
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Salicylic acid, Dinitrophenol (DNP) -
Salicylate poisoning is known to increase the body temperature. DNP is a poison with the similar effect. They too are known to be the ‘uncouplers’. -
Dantrolene sodium -
This is a different type of ‘uncoupler’.
Electrical excitation of nerve is coupled to mechanical process of contraction; the coupling agent is Ca++. In malignant hyperthermia, excessive release of Ca++ through RyR generates excessive muscle contraction (metabolism) and thereby excess heat is liberated. Dantrolene uncouples the excitation from contraction, thereby reducing the contraction and consequent heat.