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Query: UMLS:C0344307 (analgesia)
 28,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of taurine on the analgesic response to morphine, on the intensity of tolerance and on physical dependence were examined. Taurine induced a hyperalgesic state and attenuated morphine analgesia in mice. The hyperalgesia was maximal at a dose level of 1.5 mg/kg i.p., while the effects of higher doses (6.0 and 10.0 mg/kg) were masked by a depression of the animals' gross behavior. Taurine induced a dose related antagonism of morphine tolerance. The amino acid administered 30 min before naloxone, produced a partial reduction in the abstinence signs in the chronically treated mice. Taurine also attenuated the abstinence behavior when administered during the course of dependence. The results are consistent with taurine antagonism to the known effects of morphine on intracellular calcium disposition in nervous tissue.
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PMID:Effects of taurine on tolerance to and dependence on morphine in mice. 653 78

The calcium entry blocker, verapamil, enhanced morphine analgesia, but neither methadone nor propoxyphene analgesia was affected by verapamil in the mouse hot-plate test. To explain this, it was hypothesized that methadione and propoxyphene differ from morphine because they, like verapamil, block calcium channels and subsequent studies were done to confirm this. Verapamil, methadone and propoxyphene all depressed barium-induced bovine adrenal catecholamine release and KCl-induced contractions of guinea pig ileum, which are known to be calcium-dependent events. Calcium reversed opioid-induced inhibition in both tissues. Morphine did not affect either catecholamine release or ileal contractions. Procaine also did not influence catecholamine release or ileal contraction. Therefore, local anesthesia was eliminated as a mechanism for the inhibitory action of methadone and propoxyphene in these tissues. Opioids which block calcium channels should, like verapamil, produce bradycardia and hypotension. In the spinal vagotomized rat, methadone, propoxyphene, and verapamil produced bradycardia and hypotension, whereas, morphine produced tachycardia and (at low doses) hypertension. The results of this work suggest that methadone and propoxyphene, in contrast to morphine, block calcium channels in a manner similar to verapamil, and that some pharmacological and especially toxicological differences between these drugs are due to different degrees of verapamil-like calcium channel blockade.
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PMID:Calcium channel blockade by certain opioids. 666 95

Using a modified tail-flick procedure we have found a highly significant hyperalgesic response in narcotic dependent mice peaking 12 hr following the removal of chronically implanted morphine pellets. Withdrawal-induced hyperalgesia correlated well with other signs of opiate withdrawal behavior. Intracerebroventricular injections of CaCl2, MnCl2 further enhanced the hyperalgesic response in morphine-dependent mice; morphine-dependent mice were more than twice as sensitive to calcium-induced hyperalgesia as placebo-treated controls. On the other hand, i.c.v. injections of the calcium-specific chelator EGTA produced highly significant, dose-dependent antinociceptive responses in both morphine-dependent and control mice, but morphine dependent mice were only half as sensitive to EGTA-induced analgesia as controls. Withdrawal hyperalgesia and EGTA analgesia may be directly related to changes in brain localization of calcium that have been reported previously; it is concluded that morphine and EGTA-induced analgesia may be associated with a calcium depleted state within a relatively small calcium pool of the nerve cell and that opiate withdrawal hyperalgesia is a sensitive measure of narcotic dependency that is likely associated with an increased Ca++ content in the same region.
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PMID:Hyperalgesic effects of divalent cations and antinociceptive effects of a calcium chelator in naive and morphine-dependent mice. 676 87

The analgesic effect of morphine was antagonized in mice by intracerebroventricular pretreatment with taurine, gamma-aminobutyric acid (GABA) or glycine and was potentiated by ethylene glycol tetra-acetic acid (EGTA) but not altered by L-glutamate or L-aspartate. The potentiation of morphine analgesia by EGTA was reversed by a concentration of taurine that did not alter the tail-flick response. The selective depletion of 45Ca2+ from synaptic vesicles observed with morphine administration was significantly inhibited by taurine injection (1.2 mumol/brain, i.vt.) but was not altered by the same dose of GABA. Inhibition of ATP-dependent 45Ca2+ uptake in synaptosomes by morphine was also completely reversed by taurine (10(-2)M which by itself did not alter 45Ca2+ uptake. These results suggest that antagonism of morphine analgesia by taurine may be caused by blockade of the morphine-induced inhibition of both ATP-dependent synaptosomal 45Ca2+ uptake and changes in synaptic vesicular 45Ca2+ localization, while the antagonism by GABA was not associated with synaptosomal Ca2+.
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PMID:Effects of amino acids, especially taurine and gamma-aminobutyric acid (GABA), on analgesia and calcium depletion induced by morphine in mice. 678 72

The possibility that divalent cations may antagonize opiate peptide analgesia and stress-induced analgesia was examined. Intracerebroventricular injection of low doses of Ca2+, Mn2+ and Mg2+ antagonized beta-endorphin and methionine-enkephalin analgesia. Ba2+ and Cd2+ were without effect. The ionophore, A23187, significantly antagonized beta-endorphin analgesia and the effect was increased when a low dose of Ca2+ was injected at the same time as the ionophore. Ethylene glycol tetraacetic acid (but not ethylenediamine tetraacetic acid) significantly potentiated endorphin analgesia. Stress-induced analgesia, as determined by increased tail-flick latencies following intraperitoneal injection of acetic acid, was effectively antagonized by naloxone, Ca2+ and Mn2+. The frequency of writhing following acetic acid injection was increased by both naloxone and divalent metal ions, again suggesting antagonism of endogenous opiates. These results confirm previous findings indicating that divalent metal ions (and especially Ca2+) may be involved in the actions of opiates.
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PMID:Modification of endorphin/enkephalin analgesia and stress-induced analgesia by divalent cations, a cation chelator and an ionophore. 682 Nov 93

By means of the coloured indicator transport test (phenol red 3% in calcium-hydrogen-phosphate), mucociliary function in nose and pharynx was studied in 50 patients who underwent general or ocular surgery and in 10 healthy adult subjects. Patients were anesthetized with halothane, enflurane, NLA, and epidural analgesia. At the end of surgery, mucociliary function was significantly depressed (p less than 0.001) after halothane or enflurane anesthesia, but not after NLA or epidural analgesia. Six hours following enflurane anesthesia we still found a significant depression (p less than 0.001) of mucociliary function. No difference between halothane or enflurane was noted.
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PMID:Mucociliary flow in the nose during general and epidural anesthesia. 684 56

The effect of intracellular modulators and ions on the analgetic action of the two tetrapeptide analogs, Tyr-D-Ala-Gly-Phe-NH2 and Tyr-D-Ala-Gly-Phe (NO) NH2, was studied in rat experiments. The threshold of pain reaction to electrical stimulation of the tail, evidenced by vocalization, was measured. PGE1, PGE2, PGE2 alpha, cAMP, and dibutyryl cAMP were shown to diminish the effect of the above-mentioned enkephalin analogs. In contrast to cAMP, cGMP was not active in this respect. Among the ions under study (calcium, lithium, rubidium, and cesium), cesium was shown to be the most active. It prevented the increase of the pain reaction threshold and shortened the duration of analgesia. Lithium had no antagonistic effect as regards the enkephalin-induced analgesia. Comparison of these findings with the previously obtained data on the antagonism of the substances under consideration with morphine suggests similarities in the mechanisms of modulation of the effects of opiates and opioids. At the same time the failure of lithium to antagonize the enkephalin analogs and the presence of morphine antagonism point out that the similarities in the mechanisms of ion regulation of exogenous analgetics and enkephalins cannot be regarded as complete enough.
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PMID:[Effect of prostaglandins, cyclic nucleotides and ions on the analgesic effect of enkephalin analogs]. 715 Jul 67

1,4-Dihydro-2,6-dimethyl-4(3-nitrophenyl)-3,5-pyridine carboxylic acid, 3-ethyl-5-methyl ester (nitrendipine, Bay e 5009) is a new vasodilatory calcium antagonist with pronounced hypertensive efficacy. Doses of 0.3-31.5 mg/kg p.o. lower the blood pressure of rats with spontaneous, renal and desoxycorticosterone acetate (DOCA)-hypertension. Doses of 0.03-10.0 mg/kg p.o. lower the blood pressure of dogs with renal hypertension. The hypotensive effect is about 10 times less in normotensive rats. No increase in tolerance occurred during therapeutic studies lasting 5 weeks in hypertensive rats and several days in hypertensive dogs. There were no signs either of acquired tolerance developing during these studies. Dogs in fentanyl analgesia respond to i.v. administration of 0.001-0.03 mg/kg with a reduction in peripheral vascular resistance and an increase in cardiac output and heart rate. The stroke volume remains unchanged. The vasodilatory effect occurs at different degrees in different vascular beds. The most pronounced increases in vascular flow were measured in the muscular vessels of the hind quarters and in the coronary vessels. The mesenterical, skin and brain blood flows were much less affected.
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PMID:Pharmacological studies of the antihypertensive effect of nitrendipine. 719 97

The characteristics of kyotorphin (Tyr-Arg)-induced release of Met-enkephalin from the striatum and the spinal cord of guinea pig were determined by superfusing the slices in vitro and then carrying out radioimmunoassays. Depolarization by 50 mM K+ induced a marked release of Met-enkephalin-like immunoreactivity. The potassium-induced release of Met-enkephalin was calcium-dependent. In preparations from a striatum, the addition of kyotorphin to the superfusion medium produced a concentration-dependent increase in Met-enkephalin. The kyotorphin-induced release of Met-enkephalin was calcium-dependent and was abolished by tetrodotoxin. Similar effects of kyotorphin were seen in the spinal cord preparations. Electrical field stimulation of the striatal slices at a frequency of 10 Hz also evoked significant and calcium-dependent increases in the release of Met-enkephalin and markedly enhanced the kyotorphin-induced release of Met-enkephalin, as compared to the controls not given field stimulation. These results suggest that kyotorphin depolarizes the so-called enkephalinergic neurons and releases Met-enkephalin from nerve terminals. This effect of kyotorphin may be a possible mechanism related to the manifestation of analgesia.
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PMID:Mechanism of kyotorphin-induced release of Met-enkephalin from guinea pig striatum and spinal cord. 727 59

Osseous deposits secondary to advanced carcinoma of the prostate are a common feature of the disease. These deposits are most often seen in the lumbar spine and pelvis and cause severe and intractable pain, often requiring large quantities of strong analgesia for alleviation of pain. Relief of pain can be achieved by external irradiation of these deposits, but this relief may not be permanent and the disease may be so widespread that it is impracticable to treat all the deposits by irradiation. Deposits from carcinoma of the prostrate are usually multiple and all may cause pain at the same time. A method of delivering the radiation to all the deposits at the same time has been sought. Previous studies have shown that radioactive phosphorus (P32) can be used to obtain this localisation of radioactivity at sites of osseous activity. In this study 24 patients with bone metastases from carcinoma of the prostate were treated with radiophosphorus and methyl testosterone, or radiophosphorus with parathormone and calcium. An overall response rate of 58% shows this to be an effective palliative treatment. The results suggest there is a greater response when P32 is used in conjunction with parathormone and calcium, than with methyl testosterone.
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PMID:Carcinoma of the prostate: the treatment of bone metastases by radiophosphorus. 730 44


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