Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0278080 (physical dependence)
 1,658 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The (+)-amphetamine circling rate of rats with unilateral 6-OHDA lesions in the striatum was recorded. Morphine tablets were implanted subcutaneously for chronic treatment. In the morphine-dependent animal the circling rate to amphetamine given 4 days after morphine was first implanted was depressed but after withdrawal with naloxone a day later the rate increased, returning to normal after 21 days. Barbiturate physical dependence was induced by adding increasing amounts of barbitone to the drinking water of lesioned rats over four weeks after which the amphetamine circling response was depressed and remained so after the barbituate was withdrawn. Ethanol tolerance was induced by adding ethanol to the drinking water of lesioned rats for four weeks. Neither the induction of tolerance over this period nor ethanol withdrawal had any effect on the circling response to amphetamine. The change in the response of striatal dopamine neurons to amphetamine that occurs after chronic morphine treatment, cannot be produced by chronic treatment with either barbitone or ethanol. The neurochemical bases of barbiturate and ethanol tolerance are different from morphine tolerance.
 ...
PMID:Effect of tolerance to morphine, ethanol and barbiturate on amphetamine circling in rats with a striatal dopamine lesion. 2 10

A method for the chronical administration of morphine by the oral route is discussed and compared with the production of physical dependence to morphine by injection. The method recommends the administration of Morphine HCl dissolved in a 45% sucrose syrup and given orally for 4 weeks. The initial concentration of morphine in the syrup was 1 mg/ml and was increased weekly up to 4 mg/ml at the end of the experiment. This procedure rendered the animals physically dependent on morphine as observed by drug withdrawal, when abstinence symptoms were easily identified.
 ...
PMID:The production of morphine tolerance and physical dependence by the oral route in the rat. A comparative study. 10 Aug 15

Morphine withdrawal was precipitated by injection of 3H-naloxone into restricted parts of the ventricular system of rats made tolerant to and dependent on morphine by repeated pellet implantation. The spread of the drug was evaluated by autoradiography and compared with the withdrawal signs precipitated in the same experiment. When the antagonist could spread into the tissue surrounding the 4th ventricle and the caudal parts of the aqueduct (penetration depth about 1.5 mm), a strong withdrawal syndrome was displayed. In contrast, only weak or no withdrawal signs were observed when the spread of naloxone was restricted to the surroundings of the lateral ventricles, the 3rd ventricle, and the rostromedial parts of the aqueduct. The same was true when the spread of the antagonist was limited to the ventral surface of the brain stem. It is concluded that structures located in the anterior part of the fossa Rhomboidea, and possibly also in the caudal part of the periaqueductal grey matter, are sites for the development of physical dependence on morphine giving rise to the withdrawal signs studied in these experiments.
 ...
PMID:Sites of action of morphine involved in the development of physical dependence in rats. III. Autoradiographic studies. 19 6

A series of morphine-like and nalorphine-like drugs were studied in the nondependent, morphine-dependent and cyclazocine-dependent chronic spinal dog. In the nondependent dog, three profiles of activity were found which could be utilized to distinguish between morphine, WIN 35, 197-2 and cyclazocine. Propiram, a prototypic partial agonist of the morphine type, produced morphine-like effects in nondependent dogs and both precipitated and suppressed abstinence in cyclazocine-dependent dogs as was needed to precipitate abstinence in morphine-dependent dogs. WIN 35, 197-2, a strong agonist in the guinea-pig ileum which has been shown to be resistant to antagonism by naloxone, neither precipitated nor suppressed morphine abstinence but suppressed cyclazocine abstinence. In the nondependent dog, it depressed the flexor reflex but not skin twitch reflex. Cyclazocine altered reflex activity much like WIN 35, 197-2 but produced tachycardia, tachypnea, mydriasis and canine delirum. The morphine and cyclazocine precipitated and withdrawal abstinence syndromes were qualitatively different. Twenty times as much naltrexone was needed to precipitate abstinence in morphine-dependent dogs. Nalorphine both precipitated and suppressed cyclazocine abstinence and appeared to be a partial agonist of the nalorphine-type. Morphine suppressed the cyclazocine abstinence syndrome. Cross-tolerance was not observed in ketocyclazocine-dependent dogs. These data are consistent with the hypothesis that there are strong and partial agonists of the mu and kappa types, and further, that physical dependence on morphine and cyclazocine is mediated through different receptors. WIN 35, 197-2 appears to be a pure strong agonist of the kappa type. Cyclazocine is a mu antagonist and mixed kappa and sigma agonist.
 ...
PMID:The effects of morphine and nalorphine-like drugs in the nondependent, morphine-dependent and cyclazocine-dependent chronic spinal dog. 94 50

Morphine withdrawal was precipitated by injection of various morphine antagonists into restricted parts of the ventricular system or by microinjection of levallorphan into specific brain areas of rats made dependent on morphine by repeated pellet implantation. When the antagonists could spread only within the lateral ventricles and the 3rd ventricle, a weak withdrawal syndrome was induced; by antagonist administration into the restricted 4th ventricle, however, strong withdrawal signs like jumping were elicited even at small dosages. In microinjection experiments, structures in the midbrain and the lower brain stem proved to be the most sensitive to antagonist action. Although microinjections into thalamic nuclei also had some effect, it could not be excluded that the effects were due to uncontrolled spreading of the drug. This became especially clear from experiments with tritium-labeled levallorphan. It is concluded that brain structures located in the anterior parts of the floor of the 4th ventricle and/or caudal parts of the periaqueductal gray matter are important sites of action for the development of physical dependence on morphine.
 ...
PMID:Sites of action of morphine involved in the development of physical dependence in rats. II. Morphine withdrawal precipitated by application of morphine antagonists into restricted parts of the ventricular system and by microinjection into various brain areas. 98 52

The effects of single and repeated pargyline administration on morphine antinociception in both naive and morphine-tolerant mice and on naloxone-precipitated withdrawal in morphine tolerant-dependent animals were investigated. Adult, male Swiss-Webster mice were rendered tolerant to and dependent on morphine by the s.c. pellet implantion technique. Morphine analgesia, as assessed by the tail-flick antinociceptive test, was potentiated in tolerant animals by acute adminstration of pargyline but antagonized by repeated pargyline administration; pargyline produced similar effects in non-tolerant mice and to the same relative degree. Repeated pargyline treatment during morphine pellet implantation enhanced the withdrawal jumping response precipitated by naloxone in dependent mice. Pargyline also, after a single injection, exacerbated jumping in mice undergoing abrupt withdrawal. Neither acute nor chronic pargyline administration altered the brain distribution of injected morphine in non-tolerant mice. It was concluded that pargyline may modify acute morphine actions and withdrawal without materially altering the process(es) involved in the development of tolerance and physical dependence.
 ...
PMID:Effect of pargyline on morphine tolerance and physical dependence development in mice. 98 7

1 Morphine (1-200 mg/kg s.c.) reduced the incidence and prolonged the latency of priming-induced audiogenic siezures in a dose-dependent manner. 2 This effect was reversed by naloxone (1 and 2 mg/kg) although naloxone was itself inactive. 3 This priming-induces seizure model may be useful in the study of tolerance and physical dependence.
 ...
PMID:Effect of morphine and naloxone on priming-induced audiogenic seizures in BALB/c mice. 100 Jan 29

Changes in growth rate and the development of tolerance and physical dependence during repeated morphine administration were compared in different age groups of rats. Chronic treatment of rats for 3 weeks with increasing doses of morphine resulted in an inhibition of the growth rate of older rats but not of younger rats. The magnitude and time course of the loss of body weight upon morphine withdrawal in morphine-treated rats were independent of the age of the animal. Morphine increased the "pain" threshold in rats as monitored by the electric foot-shock technique. These analgesic effects were greater in 12-week-old rats than in 4- or 7-week-old rats. Repeated administration of morphine resulted in a gradual loss of the analgesic response to morphine in all age groups. However, the rate of development of tolerance to morphine was faster in younger rats than in older rats when these animals were injected repeatedly either with a fixed dose or with equipotent doses of morphine. These investigations indicate that the rate of the development of tolerance to morphine is significantly affected by the age of the subject.
 ...
PMID:The effects of age on the development of tolerance to and physical dependence on morphine in rats. 116 53

The effects of several drugs on the kinetics of 14C-dopamine were studied in slices of rat striata in vitro. While morphine (35 muM) did not affect the uptake of 14C-dopamine into the slices, d-amphetamine (50muM) and imipramine (100 muM) strongly inhibited it. Morphine significantly slowed the K+ -induced release of the labelled dopamine; imipramine almost completely blocked it, while amphetamine h had no clear effect. The effect of morphine was dose-dependent and could be inhibited by the narcotic antagonist naloxone. The results demonstrate that each of the drug had a characteristic pattern of effects in our system studied. The inhibitory action of morphine on the dopamine release in vitro probably reflects in vivo symptoms of a central dopamine deficiency in rats (catalepsy, akinesia, muscular rigidity) after morphine application. In further series of experiments, it was studied if the sensitivity of brain dopamine receptors increased after repeated applications of morphine, which induced clear signs of physical dependence. Since chronic morphine treatment did not increase the potency of apomorphine (which directly stimulates dopamine receptors) in inducing stereotyped behavior, it is concluded that an increased sensitivity of dopamine receptors is not necessarily involved in morphine tolerance and dependence.
 ...
PMID:Studies on dopamine kinetics in rat brain tissue under the influence of morphine. 117 89

Effects of dietary proteins such as casein and egg albumin on analgesic activity of, tolerance to and physical dependence on morphine in rats were examined. There was no difference in analgesic activity after acute administration of morphine 10 mg/kg, s.c. between rats treated with casein food or egg albumin food and normal food for 5 or 21 days. The development of tolerance to morphine analgesia in rats treated with albumin food but not with casein food was suppressed during daily morphine 10 mg/kg, s.c. on 5 consecutive days. Rats were treated with casein or albumin food mixed with morphine (0.5 mg/g of food) for 5 days. Morphine intake in rats treated with albumin food was significantly decreased as compared to that with morphine admixed casein or normal food. Body weight loss by naloxone in morphine-dependent rats was significantly less in both casein food and albumin food groups than in the normal food group. These results suggest that chronic dietary treatment with albumin may produce a partial inhibition of development of tolerance to morphine analgesia and that with casein may attenuate morphine withdrawal manifestation in rats.
 ...
PMID:[Effects of dietary proteins on analgesic activity of tolerance and physical dependence on morphine in rats]. 135 65


1 2 3 4 5 6 7 8 9 10 Next >>