Brennan 2006 Biochim Biophys Acta

Brennan CM, Breen EP, Porter RK (2006) Cold acclimation and oxygen consumption in the thymus. Biochim Biophys Acta 1757:1463-8.

» PMID: 17022934

Brennan CM, Breen EP, Porter RK (2006) Biochim Biophys Acta

Abstract: Mitochondrial uncoupling protein 1 is usually associated with brown adipose tissue but has recently been discovered in rat and mouse thymus. We wished to establish whether there was a thermogenic role for UCP 1 in thymus and thus examined the effect of 5 weeks cold-acclimation on rat thymus tissue abundance, thymocyte oxygen consumption, thymus mitochondrial abundance, uncoupling protein 1 expression and function. We found that thymocytes from cold-acclimated rats had oxygen consumption rates 8 times less than those from rats held at room temperature and that thymocytes from cold-acclimated rats or rats kept at room temperature were noradrenaline insensitive. In addition, we found that thymus tissue or mitochondrial abundance was not increased after cold-acclimation. However uncoupling protein 1 expression per unit mass of mitochondria was increased after cold-acclimation, as determined by immunoblotting (not, vert, similar 1.7-fold) and GDP binding (not, vert, similar 1.5-fold). Consistent with our protein expression data, we also observed an increased, state 4 (not, vert, similar 1.5-fold), GDP-inhibitable (not, vert, similar 1.3-fold) and palmitate activatable (not, vert, similar 1.6-fold) oxygen consumption rates in isolated thymus mitochondria. However, extrapolation of our data showed that cold-acclimation only increased the amount of UCP 1 per gram of thymus tissue not, vert, similar 1.2-fold. Taken together, we conclude that UCP 1 does not have a thermogenic role in thymus. • Keywords: Uncoupling protein-1, Thymus, Thymocyte, Mitochondria, Purine nucleotide, Oxygen consumption

• O2k-Network Lab: IE Dublin Porter RK

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Organism: Mouse, Rat  Tissue;cell: Islet cell;pancreas;thymus, Fat  Preparation: Intact cells 

HRR: Oxygraph-2k