Failure of (+)-naloxone to antagonise responses to opioid peptides

Gayton, R.J.; Lambert, Lynn; Bradley, P B

doi:10.1016/0028-3908(78)90063-1

Cited by 24 publications

(5 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Predetermined behaviorally noneffective pretreatment doses of naloxone (1.0-3.2 mg/kg) and equimolar naltrexone doses (1.16-3.7 mg/kg) were administered 10-15 min prior to DMT or LSD. *P< 0.05, **P< 0.01, ***P< 0.001 narcotic antagonist is the (-)-naloxone isomer (Pert and Snyder 1973;Gayton et al 1978;Iijima et al 1978;Jacquet 1980;Herz et al 1979). Thus, it is of special interest that in the present study (+)-naloxone was inactive in potentiating the effects of DMT, confirming stereospecificity.…”

Section: Discussionsupporting

confidence: 64%

Effects of selected opioid agonists and antagonists on DMT-and LSD-25-induced disruption of food-rewarded bar pressing behavior in the rat

Ruffing¹,

Domino

1981

Psychopharmacology

View full text Add to dashboard Cite

Several opioid agonists and antagonists interact with N,N-dimethyltryptamine (DMT) and lysergic acid diethylamide-25 (LSD) in adult male Holtzman rats trained on a positive reinforcement, fixed ratio 4 (FR4) behavioral schedule, i.e., a reward of 0.01 ml sugar-sweetened milk was earned on every fourth bar press. DMT (3.2 and 10.0 mg/kg) and LSD (0.1 mg/kg) given IP with 0.9% NaCl pretreatment, disrupted food-rewarded FR4 bar pressing. Animals were pretreated IP (10--15 min) with predetermined, behaviorally noneffective doses of morphine, methadone, naltrexone, and the (+)- and (-)-enantiomers of naloxone prior to receiving DMT or LSD. Dose-dependent effects were shown with opioid agonist pretreatment. Morphine (0.32--1.0 mg/kg) and methadone (0.32 mg/kg) significantly antagonized the bar pressing disruption induced by DMT and LSD. Larger doses of morphine (3.2 mg/kg) and methadone (1.0--3.2 mg/kg) potentiated only LSD-induced effects, with no effect on DMT-treated groups. The opioid antagonists (-)-naloxone and naltrexone potentiated the disruption of bar pressing induced by DMT and LSD. Failure of (+)-naloxone to potentiate the DMT effects was attributed to a stereo-specific opioid antagonist effect of (-)-naloxone.

show abstract

Section: Discussionsupporting

confidence: 64%

Effects of selected opioid agonists and antagonists on DMT-and LSD-25-induced disruption of food-rewarded bar pressing behavior in the rat

Ruffing¹,

Domino

1981

Psychopharmacology

View full text Add to dashboard Cite

show abstract

“…However, an increase of the AP duration induced by naloxone has not been reported before. Most likely, the drug effects in atria and papillary muscles are not caused by a blocking of opioid receptors because (+ )-naloxone, which does not bind to opioid receptors (Gayton et al, 1978;Arndt & Freye, 1979), was nearly as effective as the (-)-isomer. A similar, though less prominent, lengthening of the AP duration in papillary muscles was seen with the ;A-opioid receptor agonist, morphine.…”

Section: Discussionmentioning

confidence: 99%

Influence of the optical isomers (+)‐ and (−)−naloxone on beating frequency, contractile force and action potentials of guinea‐pig isolated cardiac preparations

Brasch

1986

British J Pharmacology

View full text Add to dashboard Cite

1 Naloxone in concentrations ranging from 7.5 to 120 Amol I1 reduced the beating frequency of guinea-pig isolated atria. The ED50 was 7.9 gLmol 1-P' for the (-) 4 The influence ofmorphine (120 ;Lmol I') on papillary muscle AP was small. AP duration and FRP showed a marginal prolongation while V,,.l was slightly decreased. (-)-Naloxone 60 pmol I`had no effect on slow-response APs of K+-depolarized papillary muscles. Slow-response APs were abolished by verapamil (I pmol I').6 In left atrial strips the prolongation of the AP duration produced by 120 1tmol 1-of either (-)-or (+ )-naloxone resembled the drug effect in papillary muscles. 7 Most of the observed changes can be explained by an inhibition of the time-dependent membrane K+ outward current, an effect of naloxone that may be classified as a Class III antiarrhythmic action.Apparently this effect is not mediated by stereospecific opioid receptors.

show abstract

“…Depressant effects of naloxone on neurones in the frontal cortex and the striatum of the naive rat brain appeared to be non-specific, occurring more frequently during application of the (+ )than the (-)-isomer, as has also been observed in the rat brain stem (Gayton, Lambert & Bradley, 1978). Both (+)and (--naloxone, moreover, induced a higher incidence of inhibitory effects in the brains of morphinetolerant/dependent animals.…”

Section: Discussionmentioning

confidence: 61%

A Demonstration of Naloxone‐precipitated Opiate Withdrawal on Single Neurones in the Morphine‐tolerant/Dependent Rat Brain

Fry

Herz

Zieglgänsberger

1980

British J Pharmacology

View full text Add to dashboard Cite

A comparison has been made between the effects of microelectrophoretically applied naloxone on single neurones in the frontal cerebral cortex and the striatum of naive and of morphine-tolerant/ dependent rats, anaesthetized with a mixture of a-chloralose and urethane. 2 Specificity of the results obtained was evaluated by contrasting the effects of alternate applications of the (+)-and (-)-isomers of naloxone to the same neurones. 3 In naive rats naloxone had predominantly no effect, only a few cells revealing non-specific depressant responses to the drug. 4 In morphine-tolerant/dependent rats a higher proportion of neurones responded to naloxone; either with stereospecific excitatory responses, in which the activity evoked by L-glutamate or acetylcholine was increased, or with a non-specific inhibition, similar to that observed in naive animals. 5 It is suggested that these excitatory responses to microelectrophoretically applied (--naloxone represent opiate withdrawal responses at the single neurone level and that they reflect a latent hyperexcitability of the postsynaptic membrane in the morphine-tolerant/dependent state.

show abstract

Failure of (+)-naloxone to antagonise responses to opioid peptides

Cited by 24 publications

References 5 publications

Effects of selected opioid agonists and antagonists on DMT-and LSD-25-induced disruption of food-rewarded bar pressing behavior in the rat

Effects of selected opioid agonists and antagonists on DMT-and LSD-25-induced disruption of food-rewarded bar pressing behavior in the rat

Influence of the optical isomers (+)‐ and (−)−naloxone on beating frequency, contractile force and action potentials of guinea‐pig isolated cardiac preparations

A Demonstration of Naloxone‐precipitated Opiate Withdrawal on Single Neurones in the Morphine‐tolerant/Dependent Rat Brain

Contact Info

Product

Resources

About