The primary site for the metabolism of morphine has been the subject of controversy for some time. We studied morphine metabolism during the anhepatic phase of orthotopic liver transplantation in seven adult patients. After injection of morphine 10 mg at the beginning of this phase, the plasma and urinary concentrations of unchanged morphine, morphine-3-glucuronide, morphine-6-glucuronide and n...

Morphine has been widely accepted as the opioid agonist that sustains signaling because it does not cause receptor desensitization or internalization. This notion has led to the hypothesis that long-term morphine treatment initiates downstream adaptations that underlie tolerance and dependence. This study uses whole-cell recordings from neurons in the locus ceruleus to measure the potassium cur...

objective: in the present study, the effects of aqueous saffron extract (crocus sativus l.) on the acquisition and reinstatement of morphine-induced conditioned place preference (cpp) in mice were investigated. materials and methods: subcutaneous administration of morphine (40 mg/kg for four days) produced place preference. intraperitoneal administration of aqueous extract (40 and 80 mg/kg for ...

The aim of this study was to test whether morphine prevents the mitochondrial permeability transition pore (mPTP) opening through Zn(2+) and glycogen synthase kinase 3beta (GSK-3beta). Fluorescence dyes including Newport Green Dichlorofluorescein (DCF), 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM), and tetramethylrhodamine ethyl ester (TMRE) were used to image free Zn(2+), nitric ox...

Ingestion of placenta and amniotic fluid has been shown to enhance opioid-mediated analgesia in rats produced by morphine injection, footshock, vaginal/cervical stimulation, and during late pregnancy. The present study was designed to investigate the effects of amniotic fluid ingestion on the characteristics of morphine dependency and withdrawal. Tail-flick latencies in Long-Evans rats were det...

Sustained-release oral morphine sulphate (MST) 20 mg was administered to 11 healthy volunteers. Mean peak plasma morphine concentration was 14.8 ng ml-1, and occurred at a mean time of 142.5 min after ingestion. Analgesia assessed by an ischaemic forearm pain test increased to a maximum approximately 40 min after the calculated peak plasma concentration of morphine had been achieved, and remain...

BACKGROUND Morphine and its derivatives are key drugs in pain control. Despite its well-known analgesic properties morphine at high concentrations may be proalgesic. Particularly, short-lasting painful sensations have been reported upon dermal application of morphine. To study a possible involvement of TRP receptors in the pro-nociceptive effects of morphine (0.3 - 10 mM), two models of nocicep...

in the present study the effects of both cck receptor agonists and antagonists on antinociception induced by morphine in the tail-flick test have been evaluated. m orphine induced dose-dependent antinociception in mice. the response of morphine was potentiated by sulfated cholecystokinin-8 (cck-8s) but not by unsulfated cholecystokinin-8 (cck-8u). the cck receptor antagonists mk-329 and l-365, ...

The aim of this study was to evaluate the effect of curcumin on morphine tolerance and the corresponding cytokine/chemokine changes. Male ICR mice were made tolerant to morphine by daily subcutaneous injection for 7 days. Intraperitoneal injections of vehicle, low-dose or high-dose curcumin were administered 15 min after morphine injection, either acutely or chronically for 7 days to test the e...

INTRODUCTION Calcium/calmodulin-dependent protein kinase II (CaMKII) which is highly expressed in the hippocampus is known to play a pivotal role in reward-related memories and morphine dependence. METHODS In the present study, repeated morphine injections once daily for 7 days was done to induce morphine tolerance in male Wistar rats, after which gene expression profile of α-isoform of CaMKI...