Opioid use disorder (OUD) has become a considerable global public health challenge; however, potential medications for the management of OUD that are effective, safe, and nonaddictive are not available. Accumulating preclinical evidence indicates that antagonists of the dopamine D₃ receptor (D₃R) have effects on addiction in different animal models. We have previously reported that YQA14, a D₃R antagonist, exhibits very high affinity and selectivity for D₃Rs over D₂Rs, and is able to inhibit cocaine- or methamphetamine-induced reinforcement and reinstatement in self-administration tests. In the present study, our results illustrated that YQA14 dose-dependently reduced infusions under the fixed-ratio 2 procedure and lowered the breakpoint under the progressive-ratio procedure in heroin self-administered rats, also attenuated heroin-induced reinstatement of drug-seeking behavior. On the other hand, YQA14 not only reduced morphine-induced expression of conditioned place preference but also facilitated the extinguishing process in mice. Moreover, we elucidated that YQA14 attenuated opioid-induced reward or reinforcement mainly by inhibiting morphine-induced up-regulation of dopaminergic neuron activity in the ventral tegmental area and decreasing dopamine release in the nucleus accumbens with a fiber photometry recording system. These findings suggest that D₃R might play a very important role in opioid addiction, and YQA14 may have pharmacotherapeutic potential in attenuating opioid-induced addictive behaviors dependent on the dopamine system.
Rats ; Mice ; Animals ; Analgesics, Opioid ; Dopamine ; Heroin/pharmacology* ; Dopamine Antagonists/pharmacology* ; Receptors, Dopamine D3/metabolism* ; Morphine/pharmacology* ; Behavior, Addictive/drug therapy* ; Self Administration

OBJECTIVE: To observe the expression of discs large homolog 4 (DLG4) protein in hippocampus, amygdala and frontal cortex of rats and evaluate postsynaptic density in heroin dependence. METHODS: The rat heroin dependent model was established by increasing intraperitoneal injection of heroin. DLG4 proteins in hippocampus, amygdala and frontal cortex of heroin dependent 9, 18, 36 days rats were detected with immunohistochemical staining and compared with that in the control group. RESULTS: DLG4 proteins in hippocampus, amygdala and frontal cortex were gradually reduced with extension of heroin dependent time. CONCLUSION Heroin dependence can affect postsynaptic density of hippocampus, amygdala and frontal cortex. The changes become more apparent with extension of heroin dependence time.
Amygdala/metabolism* ; Animals ; Disks Large Homolog 4 Protein ; Frontal Lobe/metabolism* ; Heroin/pharmacology* ; Heroin Dependence ; Hippocampus/metabolism* ; Injections, Intraperitoneal ; Intracellular Signaling Peptides and Proteins/metabolism* ; Membrane Proteins/metabolism* ; Rats

OBJECTIVETo investigate the effects of catecholamine hormone on the blood and brain of heroin addicts.

METHODSRats were divided into three groups and treated with the glucose (control group), the heroin (im) (heroin group), and the combination of the intramuscular injection of reserpine and heroin (reserpine group). Changes in the levels of the dopamine (DA), cAMP, and cGMP were detected by the radioimmunoassay (RIA) method in the blood and brain tissue.

RESULTSNo significant withdrawal symptoms were observed in the reserpine group. Compared with the control and heroin groups, the blood cAMP levels were increased by 35.36% and 15.53% in the reserpine group, respectively; the cAMP levels in the midbrain ventral tegmental area (VTA), prefrontal cortex (PFC), and hippocampus (Hipp) were increased by 24.08% & 8.53%, 15.66% & 8.13%, and 21.95% & 8.40%, respectively. While compared to the control and heroin groups, the DA levels of the PFC, Hipp, striatum, and nucleus accumbens (NAc) were significantly reduced in the reserpine group, decreasing by 74.09% & 82.86%, 81.06% & 82.23%, 91.62% & 86.55% and 84.35% & 90.63%, respectively. The concentrations of cGMP of the brain tissues in the reserpine group were lower than those in the control group. In addition, the neural electrophysiological testing showed that the electroencephalogram (EEG), electrocardiogram (ECG), and muscle spindle discharge diagram of rats in both the reserpine and heroin groups were apparently changed.

CONCLUSIONCatecholamine hormone plays an important role in heroin addiction.

Animals ; Brain ; drug effects ; metabolism ; Catecholamines ; physiology ; Cyclic AMP ; blood ; metabolism ; Cyclic GMP ; blood ; metabolism ; Dopamine ; blood ; metabolism ; Heroin Dependence ; metabolism ; physiopathology ; Male ; Rats ; Rats, Wistar

OBJECTIVETo investigate the relationship between heroin spongiform leucoencephalopathy and respiratory chain complex I deficiency.

METHODSThe activity of respiratory chain complex I in peripheral white blood cell mitochondria was compared between 36 cases of heroin spongiform leucoencephalopathy and 36 healthy subjects using enzyme-linked immunosorbent assay (ELISA).

RESULTSThe activity of respiratory chain complex I was 5.6∓2.4 U/ml in patients with heroin spongiform leucoencephalopathy, significantly higher than that in the normal subjects (4.2∓2.1 U/ml, t=2.634, P<0.05).

CONCLUSIONIn patients with heroin spongiform leucoencephalopathy, mitochondrial dysfunction results in energy metabolism disorder to cause extensive demyelination of the cerebral white matter. Respiratory chain complex I deficiency of the mitochondria plays a significant role in the pathogenesis of heroin spongiform leucoencephalopathy.

Adult ; Canavan Disease ; etiology ; metabolism ; pathology ; Case-Control Studies ; Electron Transport ; Female ; Heroin Dependence ; complications ; metabolism ; pathology ; Humans ; Male ; Middle Aged ; Mitochondrial Diseases ; metabolism ; Young Adult

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

OBJECTIVETo examine the effects of Han's acupoint and nerve stimulator (HANS) electroacupuncture on the expression of NPY in periaqueductal grey (PAG) of heroin addicted rats.

METHODSHeroin was injected subcutaneously according to the principle of daily increasing dose in rats of experimented group. The ability of special learning and memory were tested by Morris water maze; The expression of NPY in PAG of rat were detected by immunohistochemistry.

RESULTS(1) Escape latency and searching distance in heroin-addiction group were significantly increased compared with those of normal group during the place navigation test (P < 0.05). However, in acupuncture group, escape latency and searching distance was obviously shortened compared with those of heroin-addiction group (P < 0.05). The exploring time and distance of original platform area in proportion to the total distance in heroin-addiction group significantly decreased compared with those of normal group during spatial probe test (P < 0.05). The exploring time and distance of original platform area in proportion to the total distance in acupuncture group was increased compared with those in heroin-addiction group (P < 0.01). (2) The expression of NPY of heroin-addiction group was lower than that in normal group in PAG, while those of acupuncture group was higher than that in the heroin-addiction group (P < 0.05).

CONCLUSIONThe learning and memory induced by heroin-addiction could be reversed and the expression of NPY in PAG was increased by HANS in rats.

Animals ; Electroacupuncture ; Heroin Dependence ; metabolism ; Male ; Maze Learning ; Memory ; Neuropeptide Y ; metabolism ; Periaqueductal Gray ; metabolism ; Rats ; Rats, Wistar

OBJECTIVE: To explore the changes of c-fos in apoptosis of cerebellar granular neuron of neonatal SD rats induced by heroin and the mechanisms of neuronal injury caused by heroin. METHODS: Primary cerebellar granular neuron were cultured in vitro, the model of apoptosis induced by heroin was established. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were adopted to investigate the changes of c-fos in cell models. RESULTS: Ten microg/mL of heroin was the optimal dose to induce the apoptosis of cerebellar granular neuron at 48 h. Both Western blotting and RT-PCR showed down regulation of c-fos expression. CONCLUSION Heroin could induce apoptosis of cerebellar granular neuron and down regulation of c-fos, which may be one of the apoptosis mechanisms.
Animals ; Animals, Newborn ; Apoptosis/drug effects* ; Blotting, Western ; Cells, Cultured ; Cerebellum/metabolism* ; Dose-Response Relationship, Drug ; Down-Regulation ; Gene Expression Regulation/drug effects* ; Heroin/pharmacology* ; Male ; Neurons/metabolism* ; Proto-Oncogene Proteins c-fos/metabolism* ; RNA, Messenger/metabolism* ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo study the changes of neutral alpha-glucoside activity in the epididymis of heroin-dependent and heroin-withdrawal rats, and to investigate the effects of intervention with purine nucleotide (AMP and GMP).

METHODSEighty Wistar rats were randomly divided into 8 groups of equal number, control, nucleotide, heroin, heroin + nucleotide, 3 d withdrawal, 9 d withdrawal, 3 d nucleotide (nucleotide administrated for 3 days after heroin withdrawal) and 9 d nucleotide (nucleotide administrated for 9 days after heroin withdrawal). Neutral alpha-glucosidase activity in the epididymis was detected in each group of rats.

RESULTSCompared with the control group, neutral alpha-glucoside activity was markedly decreased in the heroin group (P < 0.05), and also in the 3 d and 9 d withdrawal groups, although with no significant differences (P > 0.05).

CONCLUSIONHeroin reduces neutral alpha-glucoside activity in the epididymis of rats, and this effect may continue for some time after drug withdrawal, while purine nucleotide can keep neutral alpha-glucosidase activity in a relatively stable state.

Animals ; Epididymis ; chemistry ; Heroin ; adverse effects ; Heroin Dependence ; metabolism ; Male ; Purine Nucleotides ; pharmacology ; Rats ; Rats, Wistar ; alpha-Glucosidases ; metabolism

OBJECTIVE: To explore the effect of electroacupuncture on heroin seeking behavior and FosB expression in relevant brain regions. METHODS: Rat model of heroin relapse behaviors was developed with progressive fixed ratio program,and model rats were randomly divided into 3 groups: a restraint group, a needle retention group, and a electroacupuncture group. The heroin seeking behavior was elicited by a small dose of heroin. FosB expression in relevnt brain region was assessed with immunohistochemical technique. RESULTS: Tests on reinstatement of drug seeking behavior induced by heroin priming showed that compared with the restraint group, active pokes in the electroacupuncture group decreased significantly(P<0.05). Compared with the restraint group, the expression of FosB positive nuclei in Acd, Pcg and CeA of rats brain both in the electroacupuncture group and the needle retention group (P<0.05) decreased significantly. In LC, the expression of FosB positive nuclei in the needle retention group decreased significantly compared with the restraint group (P<0.05). CONCLUSION Continuous acupuncture and needle retention attentuate the reinstatement of heroin-seeking behaviors induced by heroin priming, and the inhibitory effect may be mediated partially by the expression of FosB in relevant regions which are involved in the process of heroin addiction.
Amygdala ; metabolism ; Animals ; Behavior, Animal ; Brain ; metabolism ; Electroacupuncture ; methods ; Heroin Dependence ; metabolism ; psychology ; therapy ; Male ; Nucleus Accumbens ; metabolism ; Proto-Oncogene Proteins c-fos ; biosynthesis ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the effect of M(5) muscarinic receptor subtype on the locomotor sensitization induced by heroin priming, and it's effect on the FosB expression in the nucleus accumbens (NAc) and the hippocampus in the heroin sensitized rats.

METHODSLocomotor activity was measured every 10 min for 1 h after subcutaneous injection of heroin. FosB expression was assayed by immunohistochemistry, and the antisense oligonucleotides (AS-ONs) targeting M(5) muscarinic receptor was transferred with the lipofectin.

RESULTSMicroinjection of AS-ONs targeting M(5) muscarinic receptor in the ventral tegmental area (VTA) blocked the expression of behavioral sensitization induced by heroin priming in rats. Meanwhile, the expression of FosB-positive neurons in either the NAc or the dentate gyrus (DG) of the hippocampus increased in heroin-induced locomotor sensitized rats. The enhancement of FosB-positive neurons in the NAc or DG could be inhibited by microinjection of M(5) muscarinic receptor AS-ONs into the VTA before the heroin-induced locomotor sensitization was performed. In contrast, microinjection of M(5) muscarinic receptor sense oligonucleotide (S-ONs) into the VTA did not block the expression of behavioral sensitization or the expression of FosB in the NAc or DG in the heroin sensitized rats.

CONCLUSIONBlocking M(5) muscarinic receptor in the VTA inhibits the expression of heroin-induced locomotor sensitization, which is associated with the regulation of FosB expression in the NAc and hippocampus neurons. M(5) muscarinic receptor may be a useful pharmacological target for the treatment of heroin addiction.

Acetylcholine ; metabolism ; Animals ; Brain ; drug effects ; metabolism ; physiopathology ; Heroin ; adverse effects ; Heroin Dependence ; drug therapy ; metabolism ; physiopathology ; Hippocampus ; drug effects ; metabolism ; Immunohistochemistry ; Male ; Microinjections ; Motor Activity ; drug effects ; physiology ; Narcotics ; adverse effects ; Neural Pathways ; drug effects ; metabolism ; physiopathology ; Neurons ; drug effects ; metabolism ; Nucleus Accumbens ; drug effects ; metabolism ; physiopathology ; Oligonucleotides, Antisense ; pharmacology ; Proto-Oncogene Proteins c-fos ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor, Muscarinic M5 ; antagonists & inhibitors ; genetics ; metabolism ; Synaptic Transmission ; drug effects ; physiology ; Ventral Tegmental Area ; drug effects ; metabolism ; physiopathology