Publication Date:
2008-01-19
Description:
Inflammatory diseases and neuropathic insults are frequently accompanied by severe and debilitating pain, which can become chronic and often unresponsive to conventional analgesic treatment. A loss of synaptic inhibition in the spinal dorsal horn is considered to contribute significantly to this pain pathology. Facilitation of spinal gamma-aminobutyric acid (GABA)ergic neurotransmission through modulation of GABA(A) receptors should be able to compensate for this loss. With the use of GABA(A)-receptor point-mutated knock-in mice in which specific GABA(A) receptor subtypes have been selectively rendered insensitive to benzodiazepine-site ligands, we show here that pronounced analgesia can be achieved by specifically targeting spinal GABA(A) receptors containing the alpha2 and/or alpha3 subunits. We show that their selective activation by the non-sedative ('alpha1-sparing') benzodiazepine-site ligand L-838,417 (ref. 13) is highly effective against inflammatory and neuropathic pain yet devoid of unwanted sedation, motor impairment and tolerance development. L-838,417 not only diminished the nociceptive input to the brain but also reduced the activity of brain areas related to the associative-emotional components of pain, as shown by functional magnetic resonance imaging in rats. These results provide a rational basis for the development of subtype-selective GABAergic drugs for the treatment of chronic pain, which is often refractory to classical analgesics.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Knabl, Julia -- Witschi, Robert -- Hosl, Katharina -- Reinold, Heiko -- Zeilhofer, Ulrike B -- Ahmadi, Seifollah -- Brockhaus, Johannes -- Sergejeva, Marina -- Hess, Andreas -- Brune, Kay -- Fritschy, Jean-Marc -- Rudolph, Uwe -- Mohler, Hanns -- Zeilhofer, Hanns Ulrich -- England -- Nature. 2008 Jan 17;451(7176):330-4. doi: 10.1038/nature06493.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Experimental and Clinical Pharmacology and Toxicology, University of Erlangen-Nurnberg, D-91054 Erlangen, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18202657" target="_blank"〉PubMed〈/a〉
Keywords:
Analgesics/administration & dosage/metabolism/pharmacology/therapeutic use
;
Animals
;
Brain/drug effects/physiology
;
Capsaicin/pharmacology
;
Chronic Disease/drug therapy
;
Diazepam/administration & dosage/metabolism/pharmacology
;
Disease Models, Animal
;
Fluorobenzenes/metabolism/pharmacology
;
Formaldehyde
;
Ganglia, Spinal/cytology/metabolism
;
Hot Temperature
;
Inflammation/chemically induced/drug therapy
;
Male
;
Mice
;
Neurons/drug effects/metabolism
;
Organ Specificity
;
Pain/chemically induced/*drug therapy/*metabolism/prevention & control
;
Protein Isoforms/chemistry/metabolism
;
Protein Subunits/chemistry/metabolism
;
Rats
;
Rats, Wistar
;
Receptors, GABA-A/chemistry/genetics/*metabolism
;
Spinal Cord/cytology/drug effects/*metabolism/physiopathology
;
Triazoles/metabolism/pharmacology
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
Permalink
