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Chronic opioid antagonist treatment selectively regulates trafficking and signaling proteins in mouse spinal cord


, : Chronic opioid antagonist treatment selectively regulates trafficking and signaling proteins in mouse spinal cord. Synapse 50(1): 67-76

Chronic opioid antagonist treatment produces functional supersensitivity and mu-opioid receptor (muOR) upregulation. Studies suggest a role for G-protein receptor kinases (GRKs) and dynamin (DYN), but not signaling proteins (e.g., G(ialpha2)), in regulation of muOR density following opioid treatment. Therefore, this study examined muOR density, agonist potency, and the abundance and gene expression of GRK-2, DYN-2, and G(ialpha2) in mouse spinal cord after opioid antagonist treatment. Mice were implanted with a 15 mg naltrexone (NTX) or placebo pellet and 8 days later pellets were removed. At 24 and 192 h following NTX treatment, mice were tested for spinal DAMGO analgesia. Other mice were sacrificed at 0 or 192 h following NTX treatment and G(ialpha2), GRK-2, and DYN-2 protein and mRNA levels determined. [(3)H] DAMGO binding studies were also conducted. Immediately following NTX treatment (0 h), muOR density was increased (+ approximately 135%), while 192 h following NTX treatment muOR density was unchanged. NTX increased DAMGO analgesic potency (3.1-fold) 24 h following NTX treatment, while there was no effect at 192 h. NTX decreased protein and mRNA abundance of GRK-2 (-32%; -48%) and DYN-2 (-25%; -29%) in spinal cord at 0 h. At 192 h following 8-day NTX treatment, GRK-2 protein and mRNA were at control levels, while DYN-2 protein remained decreased (-31%) even though DYN-2 mRNA had returned to control levels. G(ialpha2) was unaffected by NTX treatment. These data suggest that opioid antagonist-induced mu-receptor upregulation is mediated by changes in abundance and gene expression of proteins implicated in receptor trafficking, which may decrease constitutive receptor cycling.

US$19.90

PMID: 12872295

DOI: 10.1002/syn.10246


Other references

Anonymous, 2000: Liver from bone. Nature Biotechnology 18(2): 135-135

Graf, M.; Simon, D.; Lemke, A.; Grünberg, K.; Mang, S., 2013: Toward a non-invasive screening tool for differentiation of pancreatic lesions based on intra-voxel incoherent motion derived parameters. Early recognition of and differential diagnosis between pancreatic cancer and chronic pancreatitis is an important step in successful therapy. Parameters of the IVIM (intra-voxel incoherent motion) theory can be used to differentiate between those...

Cwikla, J.B.; Buscombe, J.R.; Parbhoo, S.P.; Thakrar, D.S.; Hilson, A.J.W., 1998: Prediction of the utility of combined mammography and scintimammography in suspected primary breast cancer using ROC curves. Journal of Nuclear Medicine 39(5 SUPPL ): 138P, May

Hosty, T.S.; McDurmont, C.I., 1975: Isolation of acid-fast organisms from milk and oysters. Acid-fast organisms were isolated from 35 of 57 raw milk and 0 of 43 pasteurized milk samples submitted routinely to central and branch laboratories in 9 different areas of Alabama, USA. 64 mycobacterial isolates from raw milk were identified as 1...

Gasser, S.M.; Ohashi, A.; Daum, G.; Böhni, P.C.; Gibson, J.; Reid, G.A.; Yonetani, T.; Schatz, G., 1982: Imported mitochondrial proteins cytochrome b2 and cytochrome c1 are processed in two steps. Cytochrome b2 of yeast is located in the space between the inner and outer mitochondrial membranes whereas cytochrome c1 is bound to the outer face of the mitochondrial inner membrane. Both proteins are made outside the mitochondria as larger prec...

Nord, M.; Hooper, M.D.; Hopwood, H., 2008: Household-level income-related food insecurity is less prevalent in Canada than in the United States. Journal of Hunger & Environmental Nutrition 3(1): 17-35

Alkozai, E.M.; Nijsten, M.W.; de Jong, K.P.; de Boer, M.T.; Peeters, P.M.J.G.; Slooff, M.J.; Porte, R.J.; Lisman, T., 2010: Immediate postoperative low platelet count is associated with delayed liver function recovery after partial liver resection. To evaluate whether a low postoperative platelet count is associated with a poor recovery of liver function in patients after partial liver resection. Experimental studies in rodents have recently suggested that blood platelets play a critical rol...

Taylor, R., 1991: Insulin action 1991. Clinical Endocrinology 34(2): 159-171

Schmid, P.; Gujer, E.; Degen, S.; Zennegg, M.; Kuchen, A.; Wuthrich, C., 2001: Polychlorierte Dibenzo-p-dioxine und Dibenzofurane (PCDD/F) in Lebensmitteln tierischer Herkunft - Dioxinuntersuchungen in der Schweiz. After the occurrence of feed with high dioxin levels the Swiss authorities started a programme for the monitoring of dioxins in foodstuffs of animal origin. Determination of the dioxin levels in 128 samples of cows milk, eggs, chickens, pork, and...

Pallas, J.E., Jr.; Michel, B.E., 1971: Infrared energy as a factor in controlled environments. The possibility that variations in the visible: infra-red radiation ratio in different growth chambers might affect leaf temperature and plant growth was investigated in chambers with equal visible radiation but which was either (a) 50%, or (b) 75...