Search results for "Morphine"
showing 10 items of 145 documents
Ethological analysis of morphine withdrawal with different dependence programs in male mice.
2002
Abstract This work was performed to clarify the differences between a long or short development of morphine dependence as well as between a recently installed or a long-term dependence. Morphine withdrawal in rats is a well-characterized phenomenon but this is not so in mice. A study of the principal withdrawal signs have been performed in mice, evaluating their specificity and particular profile of appearance in each type of dependence. Mice were divided into two groups that received increasing doses of morphine every 24 h, three groups that received increasing doses of morphine twice a day for 3 days, and a control group that received saline. Naloxone-induced opiate withdrawal was evaluat…
New dopamine D2 receptor polymorphisms in rats and association with apomorphine-induced stereotypies.
2002
Adult Wistar rats injected with the dopamine receptor agonist apomorphine display different types of motility patterns with respect to oral stereotypes and locomotor activities. It was tested whether phenotypes exhibiting either ‘sniffing’ or ‘non-sniffing’ behaviour differed in gene structures of dopamine receptors D1 or D2. Forty-five Wistar rats of both genders were tested after a single dose of apomorphine (2 mg/kg s.c.) for stereotyped behaviour. Sequence analysis of the 5′ flanking region, the 5′ untranslated region and the coding region of the two genes revealed a new sequence for the 5′ flanking region of the D1 receptor gene and two polymorphisms in the promoter region of the D2 re…
The 5-HT and alpha-adrenoceptor antagonist effect of four benzylisoquinoline alkaloids on rat aorta.
1998
Abstract The action of four benzylisoquinoline alkaloids (two aporphines—glaucine and apomorphine, a benzylisoquinoline—papaverine and a bisbenzyltetrahydroisoquinoline—antioquine) on 5-HT-induced contraction in rat thoracic aorta has been examined and compared with that of the control drugs: ketanserin, nifedipine, prazosin and phentolamine. The relaxant action on 5-HT-induced contraction was contrasted with that on the contraction induced by noradrenaline and KCl. The results obtained with control drugs show that ketanserin has clear selectivity for 5-HT receptors, whereas prazosin and phentolamine have high selectivity for the α1-adrenoceptor and nifedipine seems to have a more potent ef…
Effects of caffeine as an adjuvant to morphine in advanced cancer Patients: A randomized, double-blind, placebo-controlled, crossover study
2001
Psychomotor abnormalities are one of the complications of opioid therapy in advanced cancer patients. Caffeine has potential properties to counteract the central effects of morphine. Twelve patients receiving stable doses of slow release morphine with adequate pain relief were scheduled for this double-blind placebo-controlled crossover trial. The treatment consisted of an intravenous dose of 1/6 of the daily morphine dose, using an intravenous/oral conversion ratio of 1:3. The dose calculated was administered in 5 minutes. Patients were randomly divided to received in a double-blind manner an infusion of 200 mg of caffeine or saline solution intravenously over one hour. A crossover took pl…
Opposite vascular activity of (R)-apomorphine and its oxidised derivatives. Endothelium-dependent vasoconstriction induced by the auto-oxidation meta…
2003
We have synthetised a series of oxidised apomorphine derivatives (orto and para quinones 2-5), in order to analyse their vascular activity. We have performed radioligand binding assays on rat cortical membranes and functional studies on rat aortic rings. Instead the relaxant activity exhibited by (R)-apomorphine, o-quinones 2, 4, show contractile activity dependent on endothelium in rat aortic rings. Compound 2, the main metabolite of (R)-apomorphine auto-oxidation, was the product which showed enhanced contractile activity by a complex mechanism related to activation of Ca(2+) channels through release and/or inhibition of endothelial factors. Moreover, this compound disrupts the endothelia…
A Methanol Extract ofBrugmansia arboreaAffects the Reinforcing and Motor Effects of Morphine and Cocaine in Mice
2013
Previous reports have shown that several of the effects of morphine, including the development of tolerance and physical withdrawal symptoms, are reduced by extracts ofBrugmansia arborea(L.) Lagerheim (Solanaceae) (B. arborea). In the present study we evaluate the action of the methanol extract ofB. arborea(7.5–60 mg/kg) on the motor and reinforcing effects of morphine (20 and 40 mg/kg) and cocaine (25 mg/kg) using the conditioned place preference (CPP) procedure. At the doses employed,B. arboreadid not affect motor activity or induce any effect on CPP. The extract partially counteracted morphine-induced motor activity and completely blocked the CPP induced by 20 mg/kg morphine. On the othe…
On the opioid receptor subtype inhibiting the evoked release of 3H-noradrenaline from guinea-pig atria in vitro
1986
1. Guinea-pig isolated atria were incubated and loaded with 3H-(−)-noradrenaline. The intrinsic nerves were stimulated with trains of 5 or 35 field pulses (4 Hz), and the evoked efflux of 3H-noradrenaline and of total tritium was determined in the presence of atropine, corticosterone, desipramine, and phentolamine by liquid scintillation spectrometry. 2. Ethylketocyclazocine (1.4 nmol/l, IC50), MR 2033 (9.1 nmol/l), dynorphin A (1–13) (25 nmol/l, peptidase inhibitors present), etorphine (71 nmol/l), and [d-Ala2, d-Leu5]-enkephalin (>10 μmol/l, peptidase inhibitors present) inhibited the stimulation-evoked efflux of 3H-noradrenaline in a concentration-dependent manner, but not morphine up to…
ESRA19-0543 Analgesic effects of dexamethasone when given perineurally or intravenously in the upper arm bone fracture and shoulder joint surgery
2019
Background and aims Shoulder surgery is associated with severe pain. Pain delays rehabilitation and lowers quality of life. Finding adjuvants to the LA to improve analgesia and facilitate mobilization has been the focus of researchers recently. The aim of this work was to investigate which administration methods—dexamethasone perineural or intravenously—prevents pain more effectively. Methods Prospective, randomized study conducted at Hospital of Traumatology and Orthopaedics after ethics committee approval. Study involved 75 patients with upper limb fracture or shoulder joint surgery in RA and GA. Group I: Bupivacaine 0.25% 70 mg + Dexamethasone 8 mg perineurally Group II: Bupivacaine 0.25…
A randomised controlled study on the use of anti-inflammatory drugs in patients with cancer pain on morphine therapy
2002
The role of non-steroidal anti-inflammatory drugs (NSAIDs) in cancer pain has been well established in the treatment of mild pain and in association with opioids in the treatment of moderate to severe pain. The aim of this study was to verify the effects of NSAIDs on morphine escalation in advanced cancer patients with pain followed-up at home and to assess the pharmacoeconomic implications. A prospective randomised controlled study was carried out in 156 consecutive advanced cancer patients with pain followed-up at home in the period December 1999–December 2000. In this group of patients, 47 were selected with pain progression after 1 week of opioid stabilisation. Patients were randomly as…
The prevalence and characteristics of breakthrough cancer pain in patients receiving low doses of opioids for background pain
2021
Simple Summary The aim of this study was to assess the prevalence and characteristics of breakthrough cancer pain (BTcP) in patients receiving low doses of opioids for background pain. This prospective study showed that in this population, BTcP prevalence was 69.8%. Many patients did not achieve a sufficient level of satisfaction with BTcP medications, particularly with oral morphine. Data also suggest that better optimization of background analgesia, though apparently acceptable, may limit the number of BTcP episodes. Abstract The aim of this study was to assess the prevalence and characteristics of breakthrough cancer pain (BTcP) in patients receiving low doses of opioids for background p…