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)

The principal site of action of intravenous regional anesthesia was studied using both prilocaine HC1 0.5% and technetium pertechnetate to define their distribution in the upper limb during this method of anesthesia. Using a single upper arm tourniquet and injecting technetium pertechnetate into a cubital fossa vein, the isotope spread to the finger tips. When a double tourniquet system was used to isolate the hand from the forearm, the following results were obtained: for up to 20 min after injection of the 40 ml of normal saline and radioisotope there was no leakage into the general circulation nor into the hand; after injection of 40 ml prilocaine HCl 0.5% into a cubital fossa vein, there was no anesthesia in the hand except for a small area on the dorsum corresponding to the area of sensory distribution of the radial nerve; while the tourniquets were inflated there was cramping pain in the hand. The results indicate that the initial analgesia obtained with the intravenous regional technique was due to blockade of small nerves or possibly nerve endings and not of the major nerve trunks at the elbow as has been suggested previously.
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PMID:Site of action of intravenous regional anesthesia. 609 34

Stereospecific [3H]sufentanil binding, inhibited by dextromoramide, represents 90% of the total binding in membrane preparations of rat brain and spinal cord. Scatchard plots of the binding in the forebrain, at 37 degrees C in Tris-HCl buffer without and with 120 mM NaCl, were rectilinear; KD = 0.13 nM and 0.31 nM, Bmax = 13 fmol/mg tissue and 9.9 fmol/mg tissue in the absence and the presence of sodium ions respectively. The reduction in binding affinity in the presence of sodium ions was found to be due to a 9.7 fold enhancement of the initial dissociation rate from t1/2 = 2.1 min in the absence to 13 s in the presence of sodium ions. The [3H]sufentanil binding properties were superior to those of [3H]fentanyl, [3H]dihydromorphine and [3H]naloxone; [3H]sufentanil showed an unmatched favourable ratio of stereospecific versus non-specific binding; it had a 7.7, 20 and 40 fold binding affinity than the above ligands respectively. Due to its relatively slow dissociation rate, a more accurate estimation of the Bmax value was obtained with [3H]sufentanil than with the other, fast dissociating 3H-ligands (t1/2 less than 10 s). A total of 37 narcotic analgesic agonists and antagonists belonging to 5 different major structural classes all inhibited stereospecific [3H]sufentanil binding in a competitive way. There was no relationship between binding affinities and lipophilicity and degree of ionization of the compounds. Binding affinities correlated highly significantly with the analgesic potency measured in vivo, demonstrating that [3H]sufentanil labels mu-opiate receptor sites which mediate narcotic analgesia. Moreover, the binding affinity of sufentanil for delta-type binding sites labelled by [3H] [D-Ala2,D-Leu5]enkephalin was found to be 100 times lower than its binding affinity for the mu-receptor sites. [3H]Sufentanil was used for a detailed investigation of the regional distribution of mu-opiate receptor sites in the brain; Bmax and KD values were measured in the dorsal and ventral spinal cord.
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PMID:[3H]Sufentanil, a superior ligand for mu-opiate receptors: binding properties and regional distribution in rat brain and spinal cord. 613 25

The analgesic activity of the kappa opioid agonist, U-50,488H, was markedly antagonized by pretreatment with reserpine, p-chlorophenylalanine, and ketanserin. Likewise, analgesic doses of U-50,488H enhance serotonin metabolism. These results suggest that kappa analgesia requires serotonin acting through 5-HT2 receptors. The non-opioid analgesic, nefopam HCl, though a blocker of biogenic amine uptake, displays an analgesic spectrum of action more similar to that of amphetamine than that of the tricyclic antidepressants or serotonin uptake blockers. Likewise p-chlorophenylalanine and ketanserin do not block nefopam analgesia nor do naloxone, atropine, yohimbine, propranolol or haloperidol. However, as reserpine does block nefopam analgesia, biogenic amines acting at other receptors may be involved. The observation that m-tyrosine causes behavioral effects similar to high doses of nefopam suggested that they might be acting through similar mechanisms. However, although m-tyrosine causes analgesia, it is blocked by yohimbine. This suggests that alpha2-adrenoreceptors are involved in m-tyrosine analgesia and that it differs in mechanism from nefopam analgesia.
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PMID:Involvement of biogenic amines with the mechanisms of novel analgesics. 614 8

Morphine HCl (10 micrograms/0.5 microliter) was injected into the right striatum, the caudal aqueduct and the region of the nucleus raphe magnus of the rat. Turnover of 5-hydroxytryptamine (5-HT) in the brain was assessed by fluorimetric estimation of 5-hydroxyindol-3-ylacetic acid following the administration of probenecid. Injection into the right striatum (a region containing 5-HT terminals) increased 5-HT turnover in the right, but not in the left striatum or in the anterior medulla. The pain threshold was unaltered. Injection into the aqueduct accelerated 5-HT turnover in the anterior medulla, but the striata and spinal cord showed no such change. Analgesia was pronounced. Injection of morphine into the region of the nucleus raphe magnus analgesia and increased 5-HT turnover in the posterior medulla and the spinal cord. The action on the cord must have been the result of the stimulation of cells in the raphe. The effects of the local injections of morphine on 5-HT turnover were antagonized by systemic naloxone (1-2 mg/kg) in all the regions studied. When morphine was administered subcutaneously three times a day for five days, tolerance developed to the analgesic effect of morphine (7mg/kg). However, tolerance to its acceleration of 5-HT turnover was only seen in the spinal cord, not in striatum or anterior and posterior medulla. When morphine was withdrawn, its effects on analgesia and 5-HT turnover in the spinal cord recovered simultaneously. The results emphasize the likely part played by the descending serotoninergic pathway in the analgesic effect of morphine.
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PMID:Analgesia, development of tolerance, and 5-hydroxytryptamine turnover in the rat after cerebral and systemic administration of morphine. 618 Mar 53

A serum fraction from schizophrenic patients has been investigated for its effect on opiate receptor sites and on behaviour in rats. Serum from schizophrenic patients was ultrafiltered and fractionated on DEAE-Sephadex A-25. The concentration of peptide material eluting under 0.1 M HCl (fraction I) was further purified on Sephadex-G10 and four major peaks were identified (fractions II to V). When injected intracerebroventricularly in rats, fraction II produced a characteristic behavioural syndrome, which included hyperactivity associated with hyperemotionality. The effects were long lasting, bouts of hyperemotionality accompanied by analgesia were recorded over a two-week period. The same fraction from control non-patients produced a transient and much reduced, but qualitatively similar response. There was evidence that fraction III was also active. An in vitro opiate receptor binding test showed that fraction II from schizophrenic patients inhibited [3H]naloxone binding.
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PMID:A peptide-containing fraction of plasma from schizophrenic patients which binds to opiate receptors and induces hyper-reactivity in rats. 628 75

Rats with unilaterally sectioned sciatic nerves were continuously administered naloxone HCl (80 or 800 micrograms/h) or equivalent volumes of saline (1 or 10 microliters/h) subcutaneously via osmotic minipumps over a 2 or 5 week period. Rats receiving 80 micrograms/h naloxone for 5 weeks exhibited significantly less self-mutilation (autotomy) of the denervated foot than saline controls or rats receiving 80 micrograms/h naloxone for 2 weeks. The nociceptive threshold of intact rats infused with the same dose of naloxone was tested on a hot plate. In these animals there was no influence on the nociceptive threshold during naloxone administration for 1 week. Autotomy was also reduced in rats infused with 800 micrograms/h naloxone. The nociceptive threshold of intact rats infused with this dose of naloxone or an equivalent volume of saline (10 microliters/h) was increased, suggesting that the presence of the larger osmotic pump caused analgesia.
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PMID:Continuous naloxone administration via osmotic minipump decreases autotomy but has no effect on nociceptive threshold in the rat. 630 41

Anesthetic (120 and 160 mg/kg. i.p.) and subanesthetic (80 mg/kg) doses of ketamine HCl were found to prevent completely the depletion of whole brain serotonin (5-HT) by p-chloramphetamine (PCA). Furthermore, ketamine HCl (160 mg/kg) completely blocked the depletion of 5-HT by PCA in every individual brain region studied (Midbrain-thalamus, hypothalamus, striatum, hippocampus and cortex). Administration of ketamine alone had no effect on brain 5-HT levels. Nialamide (a monoamine oxidase (MAO) inhibitor) and fluoxetine (a selective 5-HT uptake inhibitor) also prevented the depletion of 5-HT by PCA. However, of these three agents, only nialamide prevented the depletion of 5-HT by reserpine. These results suggest that ketamine blocks PCA-induced 5-HT depletion by inhibiting 5-HT uptake and not by inhibiting MAO. Ketamine only weakly affected either [3H]5-HT or [3H]spiroperidol binding to 5-HT1 and 5-HT2 receptors respectively even at concentrations as high as 1 mM. These data support the contention that the primary direct effect of ketamine on serotonergic systems is the blockade of 5-HT uptake and that blockade of 5-HT uptake may mediate some of the behavioral effects of ketamine, such as analgesia.
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PMID:Ketamine inhibits serotonin uptake in vivo. 646 Sep 44

The application of acetic acid to the hind leg of a frog will induce a spinally mediated wiping reflex only if the acetic acid concentration is above a certain threshold. By using this reflex as the basis of a test for nociception, we show that morphine sulfate is a potent analgesic in the frog when injected into the lumbar area of the spinal cord. Significant analgesia is induced within 5 min after injection of as little as 0.0316 microgram of morphine sulfate. Low doses of morphine sulfate (0.0316 or 0.1 microgram) induce analgesia which dissipates within 1 h while for higher doses (0.316, 1.0 or 3.16 micrograms) the analgesia persists for at least 3 h. The analgesic effect of 0.316 micrograms of morphine sulfate is completely blocked by naloxone HCl at either 0.158 or 0.316 micrograms. Animals receiving naloxone alone (0.316 micrograms) appear to be slightly hyperalgesic compared to saline injected controls but this effect is not significant.
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PMID:A spinal site mediates opiate analgesia in frogs. 660

Changes in responsiveness for the stinging reaction of honeybees fixed in a holder after receiving 3 electrical shocks delivered with 1 min interval, was registered and used as measurement for the effect of 2 microliter of different solutions injected. Every shock consisted of a train of pulses of 1 msec each, delivered for 2 sec at a frequency of 100 Hz. Injection of morphine-HCl (50 to 200 n-moles/bee) produced a dose dependent reduction of the honeybee stinging response to the electrical shocks. The morphine dose that produced a 50% inhibition of the response (D50) was 148 n-moles/bee (927 micrograms/g), i.e., a value far greater than that reported for vertebrates in behavioral test of analgesia. Naloxone 1.1 micrograms/g produces a significant reduction of morphine D50 effect and at 4-5 micrograms/g, a full disinhibition. Thus, whereas the D50 of morphine for honeybees is far greater than that for vertebrates, the doses of naloxone that antagonize morphine are similar for bees and vertebrates. Possible explanations of this difference are mentioned. Injections of met-enkephalin, leu-enkephalin, kyotorphin and (D-Ala2) methionine-enkephalinamide, given in doses of 200 n-moles/bee, an amount greater than that of the morphine D50, exhibited no effect on the stinging response.
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PMID:The stinging response of the honeybee: effects of morphine, naloxone and some opioid peptides. 665 18

A new technique for producing continuous caudal epidural analgesia (CEA) and caudal subarachnoid analgesia (CSA) in adult horses (mares) without causing loss of pelvic limb function is described. A modified 17-gauge Huber-point directional needle was used to place a catheter with stylet into either the epidural or subarachnoid space at the lumbosacral intervertebral junction. The catheter was positioned at either the midsacral (S2-3) subarachnoid space or caudal portion of the sacral (S-3 to S-5) epidural space in 7 mares. The position of the catheter was confirmed radiographically. A 2% solution of mepivacaine HCl was used at an average dose of 0.061 +/- 0.013 mg/kg (1.3 +/- 0.3 ml) to produce CSA and 0.196 +/- 0.034 mg/kg (4.1 +/- 0.7 ml) to produce CEA. Onset of analgesia to superficial and deep muscular pinprick stimulation was faster with CSA than it was with CEA (8.2 +/- 2.4 minutes vs 21.4 +/- 3.8 minutes). Maximal caudal analgesia extended from spinal cord segments S-1 to coccyx during CSA and CEA. Periods of analgesia were shorter with CSA than with CEA (70.0 +/- 21.8 minutes vs 102.1 +/- 13.2 minutes). Perineal (S-4 to S-5) dermatome subcutaneous temperature was increased after epidural and subarachnoid injections of mepivacaine HCl solution. Heart rate, respiratory rate, systolic, diastolic, and mean arterial blood pressures, pulse pressure, rectal temperature, arterial blood gas tensions (PaCO2, PaO2), pHa, hematocrit, and total solid concentrations did not change significantly (P greater than 0.05) from base-line values after injection. The benefits and potential complications of CSA and CEA in horses are discussed.
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PMID:Continuous caudal epidural and subarachnoid anesthesia in mares: a comparative study. 666 Jun 18


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