Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344307 (analgesia)
 28,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In 79 Sprague-Dawley rats, we determined the effect of either intrathecal or subepineural capsaicin injection on: latency of withdrawal of the hind foot to a nociceptive thermal stimulus (50 +/- 1 degree C hot plate) and the onset and severity of putative behavioral evidence of chronic pain in the rat (autotomy) which commonly appears following sciatic nerve section. Capsaicin (50 micrograms) was suspended in 5 microliters of vehicle (10% Tween-80 in 0.9% saline) then injected either intrathecally at the level of the L4-5 vertebral interspace or subepineurally in the sciatic nerve at the level of the midfemur. Subepineural capsaicin consistently and efficiently produced thermal analgesia in the rat, while intrathecal capsaicin had no significant analgesic effect. In chronically denervated rats, both subepineural and intrathecal capsaicin decreased the latency to onset of first autotomy, and intrathecal capsaicin increased the severity of this behavior significantly. These data are consistent with the hypothesis that autotomy is the rat's response to abnormal sensations perceived in the denervated hind limb. Deafferentation of dorsal horn neurons appears to be of paramount importance in the production of autotomy while the relevance of peripherally originating spontaneous neuroma discharges to autotomy behavior is questioned.
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PMID:Effect of intrathecal and subepineural capsaicin on thermal sensitivity and autotomy in rats. 301 41

Deafferentation syndromes have in common the existence of a physical injury and/or of a functional impairment of a nerve, either somatosensory afferent (Phantom Limb Pain) and/or sympathetic efferent (Reflex Sympathetic Dystrophy). These progressively debilitating syndromes are the witness of the absence of self-limitation of neuronal sensitization, which is normally the evolution of any painful stimulation of spinal cord neurons. To some extent deafferentation syndromes could be defined as a maladaptive neuronal plasticity. The lack of complete understanding of underlying pathophysiological mechanisms gives account of the wide variety of proposed treatments and of their unpredictable and variable efficacy. This fact is also due in part to the lack of controlled studies of most of the therapeutic propositions, whose purported efficacy is usually based on anecdotal reports. Finally, the role of prevention must be strongly emphasized, focusing, if those syndromes are likely to occur following surgery, on the importance of pre- and postoperative efficient analgesia, and also, possibly, on the preemptive role of regional anaesthetic techniques.
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PMID:[Reflex sympathetic algodystrophies. Preventive and therapeutic aspects]. 874 49