Actins ; metabolism ; Animals ; Male ; Morphine ; adverse effects ; Morphine Dependence ; metabolism ; Prefrontal Cortex ; metabolism ; Proteome ; metabolism ; Rats ; Rats, Sprague-Dawley ; Substance Withdrawal Syndrome ; metabolism ; Synaptosomal-Associated Protein 25 ; metabolism

The mechanism of morphine dependent is a complex Procedure. It involves in many complex mechanisms such as the ultra-structure of synapse of special brain areas, neurotransmitter, enzymology, and so on. These mechanisms have closely correlation. In this paper we reveiwed the development in enzymological mechanism of morphine dependent enzymes including protein kinase (PK), nitric oxide synthase (NOS), superoxide dismutase (SOD), adenylate cyclase (AC), Succinate dehydrogenase (SDH)and 3beta-Hydroxy steroid dehydrogenase (3beta-HSD).
Adenylyl Cyclases/metabolism* ; Animals ; Brain/enzymology* ; Morphine Dependence/pathology* ; Nitric Oxide Synthase/metabolism* ; Protein Kinases/metabolism* ; Substance Withdrawal Syndrome/metabolism* ; Succinate Dehydrogenase/metabolism* ; Superoxide Dismutase/metabolism* ; Synapses/enzymology*

OBJECTIVETo explore if induced nitric oxide in the spinal cord mediates withdrawal syndrome in morphine-dependent rats.

METHODSMale SD rats weighing 200-250 g were employed in the present study. To set up morphine dependence model, rats were subcutaneously injected with morphine (twice a day, for 5 d). The dose of morphine was 10 mg/kg in the first day and was increased by 10 mg/kg each day. On day 6, 4 h after the injection of morphine (50 mg/kg), morphine withdrawal syndrome was precipitated by an injection of naloxone (4 mg/kg, ip). Inducible nitric oxide synthase (iNOS) inhibitors aminoguanidine (AG) was intrathecally injected 30 min before the administration of naloxone. All the rats were divided into four groups: control group, dependence group, withdrawal group, AG group. Morphine withdrawal score, touch evoked agitation scores (TEA scores), immunohistochemical and Western blot technique were used to evaluate morphine withdrawal response and the expression of iNOS in the spinal cord.

RESULTSIntrathecal injection of iNOS inhibitors AG could alleviate morphine withdrawal symptoms. Morphine withdrawal scores and touch evoked agitation scores in AG group were significantly lower than that of withdrawal group (P < 0.05). iNOS positive neurons in dorsal horn of AG group were significantly lower than that of withdrawal group (P < 0.05). Level of iNOS protein in spinal cord of AG group was significantly lower than that of withdrawal group (P < 0.05).

CONCLUSIONInduced nitric oxide in the spinal cord may mediate withdrawal syndrome in morphine-dependent rats.

Animals ; Male ; Morphine Dependence ; metabolism ; Naloxone ; pharmacology ; Nitric Oxide Synthase Type II ; metabolism ; Rats ; Rats, Sprague-Dawley ; Spinal Cord ; metabolism ; Substance Withdrawal Syndrome ; metabolism

Adult rats were implanted with sleep-wake recording electrodes in our experiments. Polygraphic signs of undisturbed sleep-wake activities were recorded for 24 h before cocaine administration, cocaine withdrawal day 1 (acute), day 8 (subacute), and day 14 (subchronic). Western blot method was performed to examine the expression levels of adenosine receptor subtypes in hypothalamus and cerebellum. Non rapid eye movement (NREM) sleep was significantly increased during nighttime (P < 0.01) and daytime (P < 0.05) on withdrawal day 8. The increase of NREM sleep was significant during nighttime (P < 0.01) and slight during daytime on withdrawal day 14, whereas both daytime and nighttime rapid eye movement (REM) sleeps were reduced markedly (P < 0.01) on withdrawal day 8 and 14. In addition, A2A receptor level was significantly enhanced on cocaine withdrawal day 8 and day 14 (P < 0.05), whereas A1 receptor level reduced markedly on withdrawal day 14 (P < 0.05). However, compared with that in the control group, no significant changes existed among adenosine A1, A2A and A2B receptors in rat cerebellum on cocaine withdrawal day 1, day 8 and day 14. Our findings suggest that sleep disorder caused by subacute and subchronic cocaine abstinence may be associated with over-expression of adenosine A2A receptor in rat hypothalamus to some extent.
Animals ; Cocaine ; adverse effects ; Dyssomnias ; chemically induced ; Electroencephalography ; Hypothalamus ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Receptor, Adenosine A2A ; metabolism ; Substance Withdrawal Syndrome

To define the molecular basis of ethanol dependence, changes in the phosphorylation of cAMP response element binding protein (CREB) in the nucleus accumbens of rats after acute and chronic ethanol administration were detected using immunohistochemistry. The results demonstrate that the expression of phospho-CREB (p-CREB) protein in the rat nucleus accumbens significantly increased after 15 min of acute ethanol exposure, reaching a peak at 30 min after ethanol administration. The increment remained after 1 or 6 h of ethanol exposure compared to the control rats. In contrast, chronic intake of ethanol solution obviously decreased the expression of p-CREB protein compared to the control rats. The decrement remained 24 h or 72 h after ethanol withdrawal, and returned to the control levels after 7 d of ethanol withdrawal. The results suggest that an acute ethanol administration led to an increase in the phosphorylation of CREB in the nucleus accumbens, but chronic ethanol administration produced a decrement, which is possibly one of the molecular mechanisms of alcohol dependence.
Alcoholism ; metabolism ; physiopathology ; Animals ; Cyclic AMP Response Element-Binding Protein ; chemistry ; metabolism ; Ethanol ; pharmacology ; Male ; Nucleus Accumbens ; metabolism ; Phosphorylation ; Rats ; Rats, Sprague-Dawley ; Substance Withdrawal Syndrome ; metabolism ; physiopathology ; Substance-Related Disorders ; metabolism ; physiopathology

AIMTo observe the effect of melatonin (MT) on morphine withdrawal syndromes and determine the content of NO in plasma and brain tissue in morphine dependent mice.

METHODSA physical dependent model in mice was established by subcutaneous injection of morphine. MT (15 mg.kg-1, qd x 3) was given by intragastric infusion (ig) for three days. Withdrawal syndromes were induced by intraperitoneal injection of naloxon (5 mg.kg-1). The intensity of withdrawal syndromes was evaluated according to the jumping latency, the jumping times and the body weight loss. The content of NO was detected with Griess method.

RESULTSThe jumping latency of morphine withdrawal reaction was prolonged and the jumping times were reduced obviously by ig MT. The increased NO content in plasma and brain tissue in morphine dependent mice was reduced by ig MT.

CONCLUSIONThe physical withdrawal syndromes and the content of NO in plasma and brain tissue in morphine dependent mice are inhibited by MT.

Animals ; Brain ; drug effects ; metabolism ; Disease Models, Animal ; Male ; Melatonin ; therapeutic use ; Mice ; Morphine Dependence ; blood ; Nitric Oxide ; blood ; Substance Withdrawal Syndrome ; blood ; prevention & control

Extracellular signal-regulated kinase (ERK), a mitogen-activated protein kinase (MAPK), transduces a broad range of extracellular stimuli into diverse intracellular responses. It has been reported that ERK is involved in the modulation of nociceptive information and central sensitization produced by intense noxious stimuli or peripheral tissue inflammation. Our previous studies showed that the spinal neurons sensitization was involved in morphine withdrawal response. This study was to investigate the role of the spinal ERK in morphine dependence and naloxone-precipitated withdrawal response. To set up morphine-dependent model, rats were subcutaneously injected with morphine (twice a day, for 5 d). The dose of morphine was 10 mg/kg on the first day and was increased by 10 mg/kg each day. On day 6, 4 h after the injection of morphine (50 mg/kg), morphine withdrawal syndrome was precipitated by an injection of naloxone (4 mg/kg, i.p.). Using anti-phospho-ERK (pERK) antibody, the time course of pERK expression was detected by Western blot. U0126, a mitogen-activated protein kinase kinase (MEK) inhibitor, or phosphorothioate-modified antisense oligonucleotides (ODN) was intrathecally injected 30 min or 36, 24 and 12 h before naloxone-precipitated withdrawal. The scores of morphine withdrawal symptom and morphine withdrawal-induced allodynia were observed. One hour after naloxone-precipitated withdrawal, pERK expression in the spinal dorsal horn was assessed by immunohistochemical analysis and Western blot was used to detect the expression of cytosolic and nuclear fraction of pERK in the rat spinal cord. The results showed that the expression of cytosolic and nuclear fraction of pERK, not non-phospho-ERK, in the spinal cord was gradually increased following the injection of morphine. When morphine withdrawal was precipitated with naloxone, the expression of the spinal pERK further increased. Intrathecal administration of U0126 or antisense ODN against ERK decreased the scores of morphine withdrawal, attenuated morphine withdrawal-induced allodynia and also inhibited the increase of pERK expression in the spinal cord of morphine withdrawal rats. These results suggest that activation of the spinal ERK is involved in morphine-dependent and naloxone-precipitated withdrawal response.
Animals ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Male ; Morphine Dependence ; enzymology ; physiopathology ; Naloxone ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Spinal Cord ; enzymology ; Substance Withdrawal Syndrome ; enzymology ; physiopathology

The study was conducted to investigate the effect of melatonin (MEL) on the expression of β-endorphin (β-EP) in the hypothalamic arcuate nucleus (ARH) of morphine-dependent mice. For a period of 8 consecutive days, male Kunming strain mice were injected subcutaneously (s.c.) with normal saline or increasing doses (10-80 mg/kg) of morphine, and intraperitoneally (i.p.) with MEL (10, 20 or 40 mg/kg) or vehicle (5% ethanol saline) simultaneously. Withdrawal response was induced by naloxone (3 mg/kg, s.c.) at 2 h after final morphine injection on the 8th day. The potency of withdrawal response was evaluated according to the jumping times and the body weight loss. After that, the expressions of β-EP and proopiomelanocortin (POMC) mRNA in ARH were examined by immunohistochemistry and RT-PCR, respectively. The results showed that MEL (i.p., 20 mg/kg) decreased the naloxone-precipitated withdrawal responses in morphine-dependent mice significantly (P<0.05). Meanwhile, MEL increased the intensity of β-EP-like immunoreactivity and enhanced the expression of POMC mRNA in ARH (P<0.05). These results suggest that MEL increases the expression of β-EP in ARH of morphine-dependent mice, which may partly contribute to the action of MEL to inhibit the development of morphine dependence.
Animals ; Arcuate Nucleus of Hypothalamus ; drug effects ; metabolism ; Male ; Melatonin ; pharmacology ; Mice ; Morphine ; pharmacology ; Morphine Dependence ; metabolism ; Naloxone ; pharmacology ; Pro-Opiomelanocortin ; metabolism ; RNA, Messenger ; metabolism ; Substance Withdrawal Syndrome ; metabolism ; beta-Endorphin ; metabolism

OBJECTIVETo investigate the effect of Cedemex on cAMP and cGMP contents in different brain regions in morphine withdrawal rats precipitated by naloxone.

METHODA physical morphine dependent model of rats was established by subcutaneous injection of morphine in gradually increasing dosage within 7 days. cAMP and cGMP contents of VTA, cortex and hippocampus of the rat brains were determined by radioimmunoassay.

RESULTThe morphine withdrawal symptoms of rats were relieved significantly by ig Cedemex. Compared with the controls, cAMP content in the region of VTA, cortex and hippocampus of the morphine dependent rats were significantly higher (P < 0.05), while cGMP contents in those regions were significantly lower (P < 0.05). cAMP contents in the area of VTA, cortex and hippocampus of the morphine dependent rats were significantly reduced, while cGMP contents were significantly increased by ig Cedemex.

CONCLUSIONCedemex may significantly attenuate the morphine withdrawal symptoms in rats. The mechanism of this effect may be related to adjusting the contents of cAMP and cGMP in some brain regions.

Animals ; Brain ; drug effects ; metabolism ; pathology ; Cerebral Cortex ; drug effects ; metabolism ; Cyclic AMP ; metabolism ; Cyclic GMP ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Hippocampus ; drug effects ; metabolism ; Morphine ; adverse effects ; Rats ; Substance Withdrawal Syndrome ; metabolism

OBJECTIVETo investigate the effects of purine nucleotide on the expressions of follicle-stimulating hormone (FSH) and luteotrophic hormone (LH) and the ultrastructures of the distal somatotrophic and gonadotrophic cells in the pituitary gland of heroin-addicted and -withdrawal rats.

METHODSNinety-two male Wistar rats were randomly divided into a control group (ip saline for 14 d), a nucleotide group (ip AMP and GMP for 10 d), a heroin group (ip heroin for 10 d), a heroin + nucleotide group (ip AMP and GMP + heroin for 10 d), a 3 d withdrawal group (ip heroin for 10 d and killed at 14 d), a 9 d withdrawal group (ip heroin for 10 d and killed at 20 d), a 3 d nucleotide group (ip nucleotide for 3 d after 10 d heroin administration and killed at 14 d), and a 9 d nucleotide group (ip nucleotide for 9 d after 10 d heroin administration and killed at 20 d). Changes in the mRNA expressions of FSH and LH in the pituitary gland of the rats were analyzed by semi-quantitative RT-PCR, and alterations in the ultrastructures of the distal somatotrophic and gonadotrophic cells were observed under the microscope.

RESULTSThe expression of FSH mRNA was significantly increased in the nucleotide, heroin + nucleotide, 3 d nucleotide and 9 d nucleotide groups (0.099 +/- 0.018, 0.177 +/- 0.046, 0.151 +/- 0.030 and 0.184 +/- 0.028) as compared with the control group (0.045 +/- 0.009) (P < 0.01); and so was that of LH mRNA in the heroin + nucleotide, 3 d nucleotide and 9 d nucleotide groups (0.950 +/- 0.169, 0.990 +/- 0.171 and 0.960 +/- 0.147) in comparison with the control group (0.700 +/- 0.099) (P < 0.01). In the heroin group, the nuclei of the distal somatotrophic and gonadotrophic cells exhibited morphological abnormality, unclear membrane, slightly pyknotic matrix, marginal and agglutinated heterochromatin, dilated rough endoplasmic reticula, swollen mitochondria, broken and vacuolated cristae in the cytoplasm, obviously decreased number of secretory granules, and myelin bodies in some cells. However, the heroin + nucleotide group showed no significant changes in the ultrastructures of somatotrophic and gonadotrophic cells compared with the control group.

CONCLUSIONShort-term use of heroin does not obviously affect the expressions of FSH and LH mRNA in the pituitary gland of rats, while heroin + nucleotide, or nucleotide following heroin withdrawal can enhance their expressions significantly. Heroin damages the ultrastructures of the distal somatotrophic and gonadotrophic cells in the pituitary gland of male rats, and purine nucleotide can diminish or inhibit this damage.

Animals ; Follicle Stimulating Hormone ; genetics ; metabolism ; Gene Expression ; drug effects ; Heroin ; adverse effects ; Heroin Dependence ; genetics ; metabolism ; Luteinizing Hormone ; genetics ; metabolism ; Male ; Pituitary Gland ; drug effects ; metabolism ; ultrastructure ; Purine Nucleotides ; pharmacology ; Rats ; Rats, Wistar ; Substance Withdrawal Syndrome ; genetics ; metabolism