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

The latency to tail-flick response in the rat was significantly prolonged by cerebroventricular infusion of 1.0 microgram of somatostatin (SRIF) and more so with 10.0 microgram. The D-tryptophan analog was less effective than native SRIF. Pretreatment with naloxone eliminated analgesia but not seizures induced by SRIF. Recording of the EEG activity enabled determination of the specific state of the sleep-waking cycle in which the repeated tail-flick responses were tested: latency was generally longer in both control and test animals when tail immersion was performed during the state of sleep or drowsiness rather than during the awake state. Although animals receiving SRIF were less likely to fall asleep between subsequent test trails, the average latency was actually longer than after control saline infusion when the animals slept more. SRIF, unlike other releasing factors and peptides tested, showed significant activity in an opiate radioreceptor assay. The blockade of SRIF action by naloxone pretreatment, along with binding of SRIF to opiate receptors in vitro, suggest opiate receptors to be involved in the mediation of analgesia observed in present study.
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PMID:Opiate-like naloxone-reversible actions of somatostatin given intracerebrally. 63 75

Nucleus Raphe Magnus (NRM) is a complex cell group. 5-HT, SP and ENK neurons in the NRM were identified by immunocytochemistry method. The afferent fibers containing 5-HT, SP, M-ENK, L-ENK, B-EP and SRIF were observed in NRM, the efferent fibers containing 5-HT, SP, ENK and TRH from NRM to spinal cord were studied. Two neurotransmitters (such as 5-HT with SP, ENK or TRH) were found in same neuron, fiber or vesicle. The neurons and axo-dendritic synapses of the NRM were analysed during Electroacupuncture (EA). The NRM increased their synaptic releases and the neurons were in active functional state during EA "Zusnanli". Studies show that NRM is one of important positions in EA analgesia.
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PMID:[Relationship between acupuncture analgesia and neurotransmitters in nucleus raphe magnus]. 752 92

Somatostatin is distributed in the substantia gelatinosa in the dorsal horn of the spinal cord, and its application has been found to produce an inhibitory effect on nociceptive neurons. Although intraspinal administration of somatostatin-14 produces pain relief in patients with cancer and in postoperative patients, its short half-life limits its clinical usefulness. Octreotide, a synthetic analog of somatostatin, is more stable and not been associated with neurodegenerative changes when administered intrathecally in dogs. Intrathecal octreotide provides analgesia without adverse drug effects when administered chronically for cancer pain; however, treatment periods have been limited. This article describes the 5-year clinical course of two patients receiving intrathecal octreotide for severe, intractable nonmalignant pain. Included in this description are the results of blinded, randomized "N of 1" trials conducted in each of these patients.
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PMID:Intrathecal octreotide for relief of intractable nonmalignant pain: 5-year experience with two cases. 874 73

Intrathecal administration of octreotide, a stable somatostatin analogue, provides pain relief in patients, and locally applied somatostatin inhibits firing of nociceptive dorsal horn neurons. In the present study, we have raised polyclonal antibodies that specifically detect the somatostatin receptor sst2A and used these antisera for immunocytochemical localization of the receptor protein in the rat spinal cord and dorsal root ganglia. In the superficial layers of the dorsal horn, sst2A-like immunoreactivity (Li) formed a dense network consisting of neuronal perikarya and dendrites which were often closely apposed by, but not co-contained within, somatostatin-14-immunoreactive nerve fibres and terminals. sst2A-Li was resistant to dorsal rhizotomy and did not colocalize with either substance P or calcitonin gene-related peptide suggesting that sst2A-Li was not located to primary afferents, but rather confined to second-order spinal neurons. The position of sst2A-Li perikarya and dendrites in the dorsal horn appeared to be similar to those containing mu-opioid receptor-Li; however, double labelling experiments revealed no instances of coexistence of these two receptors. sst2A-Li was also observed in the dorsal root ganglia predominantly targeted to the somatic plasmalemma of medium size neurons distinct from those expressing somatostatin-14 or delta-opioid receptors. Thus, the present results not only provide a morphological substrate for spinal octreotide analgesia but also show that somatostatin and opioids are poised to modulate nociceptive transmission by distinct anatomical systems.
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PMID:Immunocytochemical localization of somatostatin receptor sst2A in the rat spinal cord and dorsal root ganglia. 987 49

Our hypothesis is that peripheral somatostatin (SRIF) has a role in counter-irritation-induced analgesia. Our paradigm involves the reduction of nociceptive behaviors produced by primary noxious stimuli (formalin or complete Freund's adjuvant [CFA] in the rat hind paw) by a counter-irritating stimulus (capsaicin [CAP] in the tail or muzzle). Activation of peripheral SRIF receptors is key since an SRIF receptor antagonist cyclo-somatostatin (c-SOM) and SRIF antibodies in the hind paw attenuate the counter-irritation-induced analgesia of both formalin and more persistent CFA nociception. Specificity of c-SOM is shown by reversal of its effects with octreotide, a SRIF analog. Injection of formalin in one hind paw and c-SOM in the other does not reduce the counter-irritation analgesia demonstrating local action of the c-SOM. Approximately 33% of peripheral sensory axons contain SRIF, which could release the peptide to activate SRIF receptors on cutaneous axons. Intraplantar naloxone has no effect on the counter-irritation analgesia indicating that SRIF is not activating opioid receptors. These results indicate that in addition to the classic central descending noxious inhibitory control systems that underlie counter-irritation-induced analgesia, there is a peripheral contribution arising from activation of SRIF receptors. Identifying a peripheral contribution of SRIF to mechanisms of counter-irritation analgesia offers opportunities for peripheral therapy.
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PMID:A role for peripheral somatostatin receptors in counter-irritation-induced analgesia. 1289 May 19