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)

Possible involvement of cerebral delta opioid receptors in antinociceptive processes was studied in a test utilizing heat as the noxious thermal stimulus. The investigation focused on selective agonists and antagonists for mu and delta opioid receptors. Morphine and [D-Ala2,NMPhe4, Gly-ol]enkephalin (DAGO) were used as agonists for the mu receptor while [D-Pen2,D-Pen5]enkephalin (DPDPE) was the agonist for the delta receptor. Two approaches were employed: first, the intracerebroventricular (i.c.v.) analgesic activity of the agonists was determined in the absence, and in the presence of graded i.c.v. doses of the selective delta antagonist, ICI 174,864 (N,N diallyl-Tyr-Aib-Aib-Phe-Leu-OH) (where Aib is alpha-aminoisobutyric acid); second, acute tolerance to morphine was produced and the possible presence of acute cross-tolerance between subcutaneous (s.c.) morphine and the delta agonist investigated. ICI 174,864 antagonized the analgesia produced by DPDPE, but not that resulting from morphine or DAGO. Morphine pretreatment resulted in the development of acute tolerance to i.c.v. morphine, and acute cross-tolerance to i.c.v. DAGO, but not to i.c.v. DPDPE. These results provide evidence that both cerebral delta and mu opioid receptors are responsible for the mediation of analgesia in tests utilizing heat as the nociceptive stimulus.
NIDA Res Monogr 1986
PMID:Evidence for delta receptor mediation of [D-Pen2,D-Pen5]-enkephalin (DPDPE) analgesia in mice. 282 89

The icv administration of potassium chloride a few min before the icv injection of opioids, antagonized the supraspinal analgesia induced by these substances in the mouse. The antagonistic effect of a single injection of KCl lasted for 3 to 4 days and was accompanied by opposite changes in 3H-DADLE binding to mesencephalic (decrease) and spinal cord (increase) membranes.
NIDA Res Monogr 1986
PMID:A single icv injection of KCl induces a selective and long-lasting inhibition of opioid analgesia in mice. 282 91

The icv injection of morphine or DADLE ED50 a few min before the alkylating agent beta-FNA resulted in complete protection of their respective analgesic effects when evaluated 24h later, although a little cross-protection could be observed. The analgesia evoked by DADLE was partially protected using higher doses of morphine before beta-FNA. However, higher doses of DADLE did not protect the analgesia induced by morphine. On the other hand, the antagonistic action of KCl on opioid analgesia was found to be dependent on the opioid utilized to protect the opioid receptor against the effect of beta-FNA. These results are discussed in terms of multiple receptors mediating opioid analgesia at supraspinal level in the mouse.
NIDA Res Monogr 1986
PMID:Opioid analgesia in the mouse: evidence for multiple receptors using beta-FNA. 282 93

Intrathecal injection of subanalgesic doses of morphine (7.5 nmol) and dynorphin-A-(1-13) (1.25 nmol) in combination resulted in a marked analgesic effect as assessed by tail flick latency in the rat. The analgesic effect of the composite of dynorphin/morphine was dose-dependent in serial dilutions and not accompanied by any signs of motor dysfunction. Synergism between dynorphin and morphine can also be demonstrated without motor dysfunction, when dynorphin is injected together intrathecally with a serial increasing dosages of morphine. Metenkephalin showed an analogous synergistic effect with dynorphin and also morphine in the spinal cord, although dynorphin (and also metenkephalin) antagonized morphine analgesia by the intraventricular route. The underlying mechanism of the interactions among different classes of opioid ligands at different levels of the central nervous system deserves further study.
NIDA Res Monogr 1986
PMID:Modulators of pain in the spinal cord. 289 78

The hyperphagia and obesity induced by ventromedial hypothalamic (VMH) electrolytic lesions in female rats were associated with a 70-94% decrease in the level of beta-endorphin (beta-E) in the hypothalamus and other regions of brain, but not in the pituitary. Dynorphin (Dyn) and methionine-enkephalin (ME) levels were also decreased. Rats with VMH lesions were less sensitive to the inhibitory effect of naloxone on their food-intake. Mice injected with gold thioglucose (GTG) also showed a decrease in the hypothalamic content of beta-E and Dyn and exhibited 30% less analgesia compared to control mice after cold swim stress.
NIDA Res Monogr 1986
PMID:Effect of electrolytic and chemical ventromedial hypothalamic lesions on food intake, body weight, analgesia and the CNS opioid peptides in rats and mice. 289 79

Rats were given a daily opportunity to consume a sweetened ethanol solution (ES) or water until they took about 2.0 g/kg of pure ethanol (E) during 1.5 hr/day. Then, rats were given one of a number of opioids before an opportunity to drink. Some opioids, e.g., morphine (MOR), methadone, and fentanyl, at small doses, increase ES-intake; some decrease intakes, e.g., naloxone (NX) and MR 2266. Diprenorphine, a mixed agonist-antagonist having no analgesic potential and blocking other opioids' analgesia, increases ES-intake across a wide range of doses beginning with 0.003 mg/kg.
NIDA Res Monogr 1986
PMID:Opioids and intake of alcoholic beverages. 312 50

BAM-18, a new endogenous opioid containing 18 amino acid residues, was tested in 3 behavioral paradigms. Tail-flick analgesia, a spinally mediated response, hot-plate analgesia, a centrally mediated response, and open-field locomotor activity. Rats were stereotaxically implanted with a unilateral cannula aimed at the lateral ventricle. Following recovery, each animal was tested in one of the paradigms after receiving an intraventricular injection of BAM-18, morphine or the Ringer's vehicle. BAM-18 produced significant tail-flick analgesia only at doses (50 micrograms) 50 times higher than those needed with morphine (1 microgram). BAM-18 produced an extended hyperalgesia at lower doses (5 micrograms) that was also seen transiently at the high dose. The analgesia but not the hyperalgesia was reversed by naloxone (10 mg/kg, s.c.). BAM-18 produced significant naloxone-reversible hot-plate analgesia, but again it was less potent than morphine (50 micrograms for BAM-18 vs. 5 micrograms for morphine). There was no evidence of hyperalgesia in this paradigm. Locomotor activity, following 50 micrograms of BAM-18, resembled control injections for the first 18 minutes, then became reduced in a manner similar to morphine (5 micrograms). This reduction in activity was completely reversed by naloxone. These data suggest that BAM-18 is indeed an opioid molecule but is at least 10 times less potent at altering behavior than morphine.
NIDA Res Monogr 1986
PMID:Intraventricular administration of BAM-18: antinociceptive and locomotor activity in the rat. 312 62

Ten term parturients with moderate-severe preeclampsia received intrathecal morphine for labor analgesia. Significant reductions in blood pressure and heart rate, which were unrelated to analgesia, were observed.
NIDA Res Monogr 1986
PMID:Intrathecal morphine and blood pressure in preeclampsia. 312 69

Heroin hydrochloride is approximately twice as potent as morphine sulfate, and acts slightly faster but for a shorter duration than morphine. Although patients with chronic pain due to advanced cancer differ from cancer patients with postoperative pain in terms of their degree of tolerance to the analgesic effects of morphine and heroin and their reports of various elements of mood, there is, thus far, no indication that heroin has any unique advantage over morphine in terms of side effect occurrence or effects on mood at equianalgesic doses. Both drugs improve mood provided they are administered in doses which result in analgesia. While there appears to be some slight difference in the spectrum of side effects observed after heroin as compared to morphine, heroin and morphine share the most common side effects. The incidence of side effects following both drugs appear to be highest among those effects which are primarily somatic and undesirable. The use of visual analog scales concurrent with categorical pain and pain relief scores provides a means for the finer estimation of relative analgesic potency and time action. The results of these studies are in general agreement with those of other investigators. Where apparent differences exist they can usually be explained on the bases of differences in methods and subject populations.
NIDA Res Monogr 1981 Feb
PMID:Relative analgesic potency of intramuscular heroin and morphine in cancer patients with postoperative pain and chronic pain due to cancer. 678 35

In the screening and selection of candidate long-acting narcotic antagonist preparations, careful consideration must be given to the choice of animal evaluation models. A simple, rapid method, using analgesia suppression in the mouse tail-flick test, was chosen for preliminary screening. Suitable candidates were then evaluated by following urinary excretion rates and blood levels in the monkey. Afterwards, the most promising preparations were rigorously tested in their ability to interfere with morphine self-administration in monkeys. Final evaluation involved toxicological studies in injection sites and on the whole animal.
NIDA Res Monogr 1981
PMID:Background on animal testing in the drug delivery systems program. 679 Oct 14


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