Cachexia is characterised by a progressive weight loss due to depletion of both skeletal muscle and adipose tissue. The loss of adipose tissue is due to the production of a tumour-derived lipid mobilising factor (LMF), which has been shown to directly induce lipolysis in isolated epididymal murine white adipocytes. The administration of LMF to a non-tumour bearing mice produced a rapid weight loss, with a specific reduction in carcass lipid with also some redistribution of lipid with the accumulation of lipid in the liver. There was also up-regulation of uncoupling protein-1 and -2 mRNA and protein expression in brown adipose tissue, suggesting that an adaptive process occurs due to increased energy mobilisation. There was also up-regulation of UCP-2 in the livers of LMF treated mice, suggesting a protective mechanism to the build up of lipid in the livers, which would produce free radical by-products. LMF was also shown to stimulate cyclic AMP production in CHO-K1 cells transfected with human -3 adrenergic receptors and inhibited by the -3 antagonist SR59230A. LMF binding was also inhibited by SR59230A in isolated receptors. This suggests that LMF mediates its effects through a 3 adrenergic receptor. There were also changes in glucose and fatty acid uptake in LMF treated mice, which suggests metabolic changes are occurring. The study suggests that a tumour derived lipolytic factor acts through the 3 adrenoceptor producing effects on lipid mobilisation, energy expenditure and glucose metabolism.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:393298 |
| Date | January 2002 |
| Creators | Russell, Steven T. |
| Publisher | Aston University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://publications.aston.ac.uk/10996/ |
Page generated in 0.0058 seconds