Just put these up in another thread (also started by Sandra) but I keep thinking how much Vicc would have enjoyed them. So here goes:
(1)
Cutaneous tactile allodynia associated with microvascular dysfunction in muscle, Laferrière A, Millecamps M, Xanthos DN, Xiao WH, Siau C, de Mos M, Sachot C, Ragavendran JV, Huygen FJ, Bennett GJ, Coderre TJ,
Molecular Pain, 2008 Oct 28;4:49, free full text at
http://www.ncbi.nlm.nih.gov/entrez/u.../content/4//49
ABSTRACT:
BACKGROUND: Cutaneous tactile allodynia, or painful hypersensitivity to mechanical stimulation of the skin, is typically associated with neuropathic pain, although also present in chronic pain patients who do not have evidence of nerve injury. We examine whether deep tissue microvascular dysfunction, a feature common in chronic non-neuropathic pain, contributes to allodynia.
RESULTS: Persistent cutaneous allodynia is produced in rats following a hind paw ischemia-reperfusion injury that induces microvascular dysfunction, including arterial vasospasms and capillary slow flow/no-reflow, in muscle. Microvascular dysfunction leads to persistent muscle ischemia, a reduction of intraepidermal nerve fibers, and allodynia correlated with muscle ischemia, but not with skin nerve loss. The affected hind paw muscle shows lipid peroxidation, an upregulation of nuclear factor kappa B, and enhanced pro-inflammatory cytokines, while allodynia is relieved by agents that inhibit these alterations. Allodynia is increased, along with hind paw muscle lactate, when these rats exercise, and is reduced by an acid sensing ion channel antagonist.
CONCLUSION: Our results demonstrate how microvascular dysfunction and ischemia in muscle can play a critical role in the development of cutaneous allodynia, and encourage the study of how these mechanisms contribute to chronic pain. We anticipate that focus on the pain mechanisms associated with microvascular dysfunction in muscle will provide new effective treatments for chronic pain patients with cutaneous tactile allodynia. [Emphasis added.]
PMID: 18957097 [PubMed - indexed for MEDLINE]
PMCID: PMC2584041
http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum
and
(2)
Effect of tadalafil [
Cialis®]
on blood flow, pain, and function in chronic cold complex regional pain syndrome: a randomized controlled trial, Groeneweg G, Huygen FJ, Niehof SP, Wesseldijk F, Bussmann JB, Schasfoort FC, Stronks DL, Zijlstra FJ, BMC Musculoskeletal Disorder 2008 Oct 20;9:143, free full text at
http://www.ncbi.nlm.nih.gov/entrez/u...471-2474/9/143
ABSTRACT:
BACKGROUND: This double-blind, randomized, controlled trial investigated the effect of the phosphodiesterase-5 inhibitor tadalafil on the microcirculation in patients with cold Complex Regional Pain Syndrome (CRPS) in one lower extremity.
METHODS: Twenty-four patients received 20 mg tadalafil or placebo daily for 12 weeks. The patients also participated in a physical therapy program. The primary outcome measure was temperature difference between the CRPS side and the contralateral side, determined by measuring the skin temperature with videothermography. Secondary outcomes were: pain measured on a Visual Analogue Scale, muscle force measured with a MicroFet 2 dynamometer, and level of activity measured with an Activity Monitor (AM) and walking tests.
RESULTS: At the end of the study period, the temperature asymmetry was not significantly reduced in the tadalafil group compared with the placebo group, but there was a significant and clinically relevant reduction of pain in the tadalafil group. Muscle force improved in both treatment groups and the AM revealed small, non-significant improvements in time spent standing, walking, and the number of short walking periods. CONCLUSION: Tadalafil may be a promising new treatment for patients that have chronic cold CRPS due to endothelial dysfunction, and deserves further investigation.
PMID: 18937830 [PubMed - indexed for MEDLINE] PMCID: PMC2575214
http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum
regards,
Mike