RESUMEN
Objective We aimed to investigate whether antagonism of the cannabinoid CB1 receptor (CB1R) could affect novel object recognition (NOR) memory in chronically rapid eye movement sleep-deprived (RSD) rats.Methods The animals were examined for recognition memory following a 7-day chronic partial RSD paradigm using the multiple platform technique. The CB1R antagonist rimonabant (1 or 3 mg/kg, i.p.) was administered either at one hour prior to the sample phase for acquisition, or immediately after the sample phase for consolidation, or at one hour before the test phase for retrieval of NOR memory. For the reconsolidation task, rimonabant was administered immediately after the second sample phase.Results The RSD episode impaired acquisition, consolidation, and retrieval, but it did not affect the reconsolidation of NOR memory. Rimonabant administration did not affect acquisition, consolidation, and reconsolidation; however, it attenuated impairment of the retrieval of NOR memory induced by chronic RSD.Conclusions These findings, along with our previous report, would seem to suggest that RSD may affect different phases of recognition memory based on its duration. Importantly, it seems that the CB1R may, at least in part, be involved in the adverse effects of chronic RSD on the retrieval, but not in the acquisition, consolidation, and reconsolidation, of NOR memory.
Asunto(s)
Ratas , Animales , Rimonabant/farmacología , Memoria , Sueño REM , Receptores de Cannabinoides , Cannabinoides/farmacologíaRESUMEN
ABSTRACT Objective To verify the involvement of the endocannabinoid system in the immunomodulatory profile of stem cells from human exfoliated deciduous teeth, in the presence or absence of TNF-α, and agonist and antagonists of CB1 and CB2. Methods Stem cells from human exfoliated deciduous teeth were cultured in the presence or absence of an agonist, anandamide, and two antagonists, AM251 and SR144528, of CB1 and CB2 receptors, with or without TNF-α stimulation. For analysis of immunomodulation, surface molecules linked to immunomodulation, namely human leukocyte antigen-DR isotype (HLA-DR), and programmed death ligands 1 (PD-L1) and 2 (PD-L2) were measured using flow cytometry. Results The inhibition of endocannabinoid receptors together with the proinflammatory effect of TNF-α resulted in increased HLA-DR expression in stem cells from human exfoliated deciduous teeth, as well as, in these cells acquiring an anti-inflammatory profile by enhancing the expression of PD-L1 and PD-L2. Conclusion Stem cells from human exfoliated deciduous teeth respond to the endocannabinoid system and TNF-α by altering key immune response molecules.
RESUMEN
Objective:To evaluate the role of cannabinoid type 2 receptor (CB2R) in sevoflurane postconditioning-induced reduction of intestinal ischemia-reperfusion (I/R) injury in rats.Methods:Twenty-four clean-grade healthy male Sprague-Dawley rats, aged 8-10 weeks, weighing 220-270 g, were divided into 4 groups ( n=6 each) using a random number table method: sham operation group (group Sham), intestinal I/R group (group I/R), intestinal I/R+ sevoflurane postconditioning group (group Sevo) and intestinal I/R+ sevoflurane postconditioning+ CB2R antagonist AM630 group (group AM). The model of intestinal I/R injury was established by occluding the superior mesenteric artery for 45 min followed by 2 h reperfusion.In the group Sevo, 2% sevoflurane was inhaled immediately at the beginning of reperfusion for 30 min.In the group AM, CB2R antagonist AM630 3 mg/kg was intraperitoneally injected at 1 h before ischemia, and the other treatments were similar to those previously described in group Sevo.At 2 h of reperfusion, the animals were sacrificed after anesthesia, and small intestinal tissues were obtained for microscopic examination of the pathologic changes which was scored according to Chiu and for determination of wet/dry weight ratio (W/D ratio), for detection of malondialdehyde (MDA) content (by thiobarbituric acid colorimetry), for determination of myeloperoxidase (MPO) activity (by MPO assay) and cleaved caspase-3 protein expression (by Western blot). Results:Compared with group Sham, the Chui score, W/D ratio, MDA content and MPO activity in the intestinal tissues were significantly increased, cleaved caspase-3 expression was up-regulated in group I/R ( P<0.05). Compared with group I/R, the Chui score, W/D ratio, MDA content and MPO activity in the intestinal tissues were significantly decreased, cleaved caspase-3 expression was down-regulated in group Sevo ( P<0.05). Compared with group Sevo, the Chui score, W/D ratio, MDA content and MPO activity were significantly increased, cleaved caspase-3 expression was up-regulated in group AM ( P<0.05). Conclusion:CB2R is involved in the process of sevoflurane postconditioning-induced reduction of intestinal I/R injury in rats.
RESUMEN
Objective:To evaluate the relationship between the over-expression of endocannabinoid receptor 2 (CB2R) and macrophage pyroptosis in mice.Methods:Bone marrow-derived macrophages of mice were transfected by lentivirus vector and successfully screened out two stable cell lines: lentivirus LV5 negative control cells (LV5-NC) and lentivirus LV5CB2R overexpressing cells (OE). Two cell lines were respectively divided into 3 groups ( n=18 each) using a random number table method: control group (LV5-NC-C group, OE-C group), LPS/ATP group (LV5-NC-LPS/ATP group, OE-LPS/ATP group) and CB2R specific agonist HU308 group (LV5-NC-HU308 group, OE-HU308 group). Cells in group C were commonly cultured.In LPS/ATP group, cells were incubated with LPS at a final concentration of 0.5 μg/ml for 5 h, and then incubated with ATP at the final concentration of 5 mmol/L for 1 h. In group LPS/ATP+ HU308, cells were incubated for 5 h with LPS at the final concentration of 0.5 μg/ml and HU308 at the final concentration of 10 μmol/L and then with ATP at the final concentration of 5 mmol/L for 1 h. The expression of CB2R, nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3), caspase-1, and gasdermin D (GSDMD) mRNA was detected by real-time polymerase chain reaction, the expression of caspase-1 was detected by Western blot, and the concentrations of interleukin-18 (IL-18) and IL-1β in the culture medium were determined by enzyme-linked immunosorbent assay. Results:In each cell line, compared with group C, the expression of NLRP3, caspase-1 and GSDMD was significantly up-regulated, and the concentrations of IL-18 and IL-1β were increased in group LPS/ATP ( P<0.05). Compared with group LPS/ATP, the expression of NLRP3, caspase-1 and GSDMD was significantly down-regulated, the concentrations of IL-18 and IL-lβ were decreased in group HU308 ( P<0.05). There was no significant differences in the indicators mentioned above between group V5-NC-C and group OE-C, between group LV5-NC-LPS/ATP and group OE-LPS/ATP, and between group LV5-NC-HU308 and OE-HU308 ( P>0.05). Conclusion:Over-expression of CB2R gene cannot effectively inhibit the occurrence of macrophage pyroptosis, and only activation of CB2R can inhibit it in mice.
RESUMEN
Epilepsy,a group of chronic neurological disorders characterized by spontaneous and recurrent seizures and learning and memory impairments,results in transient brain dysfunction due to sudden abnormal discharge of brain neurons.The pathogenesis of epilepsy is very complicated and has not yet been fully elucidated.The imbalance between excitatory glutamate and inhibitory gamma-aminobutyric acid (GABA) neurotransmitters in the central nervous system and changes in ionic functions of N-methyl-D-aspartate receptors directly induce epileptic seizures.The endocannabinoid system plays an important role in retrograde synaptic transmission and exerts the anti-epileptic effect in cannabinoid receptor 1 (CBR1) dependent manner by regulating the synaptic transmission of glutamatergic and GABAergic neurons and homeostatsis of ionic channel function.Elucidating the specific mechanism of action of CBR1 signaling pathway in epilepsy,can provide an effective theoretical basis and novel drug's target for clinical treatment of epilepsy.
RESUMEN
Objective To investigate the role of hippocampal cannabinoid receptor 2 (CB2R) in postoperative cognitive dysfunction (POCD) in mice.Methods Fifty-four healthy male C57BL/6 mice,aged 12-16 weeks,weighing 20-30 g,were divided into 3 groups (n=18 each) using a random number table:control group (group C),group POCD and POCD plus CB2R agonist JWH133 group (group POCD+J).The mice were subjected to an intramedullary fixation for tibial fracture under 1.5％ isoflurane anesthesia to establish POCD model.In group POCD+J,2 mg/kg JWH133 was injected intraperitoneally at a total volume of 10 ml/kg after emergence from anesthesia and then the injection was repeated once a day until the 7th day after surgery.Open field test was carried out on 1 day before surgery and 1,3 and 7 days after surgery to evaluate the locomotor activity.Fear conditioning test was carried out at 15 min after completion of open field test.Mice were sacrificed at 2 h after the end of behavioral test,and the hippocampus was harvested for determination of the expression of tumor necrosis factor-alpha (TNF-α),interleukin-1beta (IL-1β),monocyte chemotactic protein-1 (MCP-1) and CB2R (by Western blot) and expression of CD11b in hippocampal tissues (by immunofluorescence).Results There was no significant difference in the total exploring distance in open field test,percentage of freezing time in contextual fear conditioning test or percentage of freezing time in tone-fear conditioning text at each time point among the three groups (P＞0.05).Compared with group C,the percentage of freezing time in contextual fear conditioning test was significantly decreased,and the expression of TNF-α,IL-1β,MCP-1,CD11b and CB2R was up-regulated after surgery in group S (P＜0.05).Compared with group S,the percentage of freezing time in contextual fear conditioning test was significantly increased,and the expression of TNF-α,IL-1β,MCP-1,CD11band CB2R was down-regulated after surgery in group S+J (P＜ 0.05).Conclusion Activation of hippocampal CB2R may be involved in the endogenous protective mechanism of POCD in mice,and the mechanism is related to inhibiting activation of hippocampal microglia and attenuating central inflammatory responses.
RESUMEN
Objective To evaluate the role of excitatory amino acid transporter 2 ( EAAT2) in can-nabinoid receptor 2 ( CB2 receptor) activation-induced attenuation of microglial injury caused by glutamate. Methods N9 microglial cells were divided into 4 groups ( n=26 each) using a random number table meth-od: control group ( group Con) , glutamate group ( group Glu) , CB2 receptor agonist AM1241 plus gluta-mate group (group AM1241+Glu) and AM1241 plus EAAT inhibitor TBOA plus glutamate group (group AM1241+TBOA+Glu) . The cells were routinely cultured for 30 h in group Con. In group Glu, the cells were routinely cultured for 6 h, and then were incubated for 24 h in the culture medium containing gluta-mate 10 mmol∕L. In group AM1241+Glu, the cells were incubated for 4 h in the culture medium containing AM12412 μmol∕L, and then were routinely cultured for 2 h, and then were incubated for 24 h in the cul-ture medium containing glutamate 10 mmol∕L. In group AM1241+TBOA+Glu, the cells were incubated for 4 h in the culture medium containing AM12412 μmol∕L and TBOA 100 μmol∕L, and then were routinely cultured for 2 h, and then were incubated for 24 h in the culture medium containing glutamate 10 mmol∕L. The cell viability was measured by MTT assay, the activity of lactic dehydrogenase ( LDH) in supernatant was determined using colorimetric method, and the expression of EAAT2 was determined by Western blot. Results Compared with group Con, the cell viability was significantly decreased and LDH activity was in-creased in Glu, AM1241+Glu and AM1241+TBOA+Glu groups, and the expression of EAAT2 was signifi-cantly up-regulated in Glu and AM1241+Glu groups ( P<0. 05) . Compared with group Glu, the cell viabil-ity was significantly increased, LDH activity was decreased, and the expression of EAAT2 was up-regulated in group AM1241+Glu ( P<0. 05) , and no significant change was found in the parameters mentioned above in group AM1241+TBOA+Glu ( P>0. 05) . Compared with group AM1241+Glu, the cell viability was sig-nificantly decreased, LDH activity was increased, and the expression of EAAT2 was down-regulated in group AM1241+TBOA+Glu ( P<0. 05) . Conclusion The mechanism by which the activation of CB2 re-ceptor attenuates microglial injury caused by glutamate is related to up-regulating the expression of EAAT2.
RESUMEN
Objective To evaluate the effect of activating cannabinoid receptor 2 (CB2R) on sepsis-induced acute lung injury and the role of autophagy in mice.Methods Twenty-four SPF male C57BL/6 mice,aged 8-10 weeks,weighing 20-25 g,were divided into 4 groups (n=6 each) using a random number table method:sham operation group (group Sham),sepsis group (group Sep),sepsis plus CB2R agonist HU308 group (group Sep+HU308) and sepsis plus HU308 plus autophagy inhibitor 3-methyladenine group (group Sep+HU308+3-MA).Sepsis was induced by cecal ligation and puncture in anesthetized mice.HU308 2.5 mg/kg was intraperitoneally injected at 15 min after surgery in Sep+HU308 and Sep+ HU308+3-MA groups,and 15 min later 3-MA 10 mg/kg was intraperitoneally injected in group Sep+ HU308+3-MA.Lung tissues were obtained at 12 h after surgery and stained with haematoxylin and eosin for examination of the pathological changes which were scored and for determination of the expression of tumornecrosis factor-alpha (TNF-α),interleukin-18 (IL-18) and IL-1β mRNA (by real-time polymerase chain reaction),expression of autophagy-related protein 5 (Atg5) (by immuno-histochemistry),and expression of microtubule-associated protein 1 light chain 3 (LC3),Beclin-1 and p62 (by Western blot).The ratio of LC3Ⅱ to LC3Ⅰ (LC3Ⅱ/LC3Ⅰ ratio) was calculated.Results Compared with group Sham,the expression of TNF-α,IL-18 and IL-1β mRNA was significantly up-regulated,and LC3 Ⅱ/LC3 Ⅰ ratio and lung injury score were increased in the other three groups,the expression of Beclin-1 was up-regulated,and the expression of p62 was down-regulated in group Sep and group Sep+HU308,and the expression of p62 was significantly up-regulated in group Sep+HU308+3-MA (P＜0.05).Compared with group Sep,the expression of TNF-α,IL-18 and IL-1β mRNA was significantly down-regulated,the expression of Atg5 was up-regulated,and lung injury score was decreased in group Sep+ HU308 and group Sep+ HU308 + 3-MA,LC3Ⅱ/LC3Ⅰ ratio was increased,the expression of Beclin-1 was up-regulated,and the expression of p62 was down-regulated in group Sep+HU308,and the expression of Beclin-1 was down-regulated,and the expression of p62 was up-regulated in group Sep + HU308 + 3-MA (P ＜ 0.05).Compared with group Sep+ HU308,the expression of TNF-α,IL-18 and IL-1β mRNA was significantly up-regulated,the expression of Atg5 and Beclin-1 was down-regulated,LC3Ⅱ/LC3Ⅰ ratio was decreased,the expression of p62 was up-regulated,and lung injury scores were increased in group Sep+HU308+3-MA (P＜0.05).Conclusion Activating CB2R can alleviate acute lung injury in septic mice,and the mechanism may be partially related to enhancing autophagy and reducing inflammatory responses.
RESUMEN
Objective@#To investigate the action and antioxidant effects of CB2 agonist AM-1241 on rat hepatic stellate cell line (HSC-T6).@*Methods@#HSC-T6 was randomly divided into four groups: control group, oxidative stress group, AM-1241 intervention group and AM-1241+AM-630 antagonist group. Survival rate of HSC-T6 was detected by thiazolyl blue assay under 24 h interventions with 0, 20, 50, 80 μmol/L AM-1241 and 0, 10, 20, 30, 40 μmol/L AM-630, respectively. Besides control group, the remaining groups were well cultured in low-glucose DMEM containing 100 mU/L glucose oxidase (GO) for 12 h to prepare the oxidative stress model. Then, AM-1241 intervention group was treated with 50 μmol/L low-glucose DMEM medium. After incubation for 12 h, the AM-1241+AM-630 antagonist group was treated with CB2 antagonist AM-630 (20 μmol/L) for 2 h, and cultured with 50 μmol/L AM-1241 in complete low-glucose medium for 12 h. The optimal drug concentration was selected according to the cell viability considered by the experiment results. Type III collagen (C III) content in the HSC-T6 supernatant was detected by enzyme-linked immunosorbent assay. Glutathione (GSH) content in HSC-T6 was detected by spectrophotometry. CB2 and heme oxygenase-1(HO-1) in each group of HSC-T6 were detected by western blotting.@*Results@#HSC-T6 proliferation was inhibited in each group of AM-1241 in a concentration-dependent manner (P < 0.05). The inhibition was highest at 80μmol/L, and the cell survival rate was (41.61% ± 3.13%) (P < 0.05). AM-630 concentration group had no significant inhibitory effect on the proliferation of HSC-T6 (P > 0.05). HSC-T6 expressed CB2 receptor in each group. The expression level of CB2 in the AM-1241 intervention group was higher compare with control group (P < 0.05).The expression of Col III were significantly higher in oxidative stress group (P < 0.05) than in control group, and the expression of Col III of AM-1241 intervention group was significantly lower than that in oxidative stress group (P < 0.05). Col III level in AM-1241+AM-630 antagonistic group was significantly higher than that in AM-1241 intervention group (P < 0.05). There was no significant difference between AM-1241+AM-630 antagonistic group and oxidative stress group (P > 0.05). The content of GSH and HO-1 in oxidative stress group was higher (P < 0.05) than control group. The content of GSH and HO-1 in the AM-1241 intervention group was higher compared with oxidative stress group, while content of AM-1241 + AM-630 antagonist group was lower compared to AM-1241 intervention group (P < 0.05), and the differences were not statistically significant for oxidative stress group.@*Conclusion@#CB2 agonist AM-1241 can inhibit the proliferation and activation of HSC-T6 and its mechanism may activate the nuclear translocation of Nrf2 binding to HSC-T6, initiating the up-regulation of antioxidant enzymes HO-1 and GSH protein expression, and thus increase the antioxidant effect of HSC-T6.
RESUMEN
Objective To study the effect of rimonabant, cannabinoid receptor 1(CB1) antagonist, on the expressions of CB1 andα-smooth muscle actin (α-SMA) in C57 mice with experimental hepatic fibrosis, and their mechanisms in liver fibrosis progression thereof. Methods Thirty C57 mice were randomly divided into three groups, normal control group, mod-el control group and model+rimonabant group, 10 mice for each group. The mouse model of experimental hepatic fibrosis was induced by intraperitoneal injection with 10%CCl4 for two weeks. The normal saline was delivered by gavage daily in normal control group and model control group. Rimonabant was given to mice in model+rimonabant group. Mice were sacri-ficed at the end of eight weeks. Samples of liver tissue were collected. The expressions of CB1 andα-SMA in liver tissue of mice were observed by immunohistochemical staining. The score of fibrosis stage (S) in liver tissue was also analyzed. Re-sults The positive expressions of CB1 andα-SMA and the score S were significantly higher in model control group and model+rimonabant group than those in normal control group (P<0.05). The positive expressions of CB1 andα-SMA and the score S were significantly lower in rimonabant group than those in model control group (P<0.05). There were positive corre-lations in CB1,α-SMA and S scores between normal control group, model control group and model+rimonabant group (P<0.05). Conclusion The activation of CB1 can promote the formation of liver fibrosis. The anti-fibrotic effect of rimonabant, CB1 antagonist, related with the inhibiting of the proliferation and activation of hepatic stellate cells (HSC), and the inhibit-ing of the expression of CB1.
RESUMEN
ObjectlveTo evaluate the role of cannabinoid receptor 2 (CB2 receptor) in microglial injury induced by glutamate.MethodsMicroglia cells were randomly divided into 4 grups:control group (group C),microglial injury group ( group Ⅰ),specific CB2 receptor agonist AM 1241 group ( group AM1241 ) and specific CB2 receptor antagonist AM630 group (group AM630).In group C,the cells were cultured routinely for 26 h.In group Ⅰ,the cells were incubated in the culture medium containing glutamate 10 mmol/L for 24 h.In group AM1241,the cells were incubated in the culture medium containing AM1241 2 μmol/L for 2 h,and then in the culture medium containing glutamate 10 mmol/L for 24 h.In group AM630,the cells were incubated in the culture medium containing AM630 2 μmol/L for 2 h,and then in the culture medium containing glutamate 10 mmol/L for 24 h.The cell viability and release of LDH were measured.Microglial morphology was observed under microscope.Results Compared with group C,the cell viability was significantly decreased,and the release of LDH was significantly increased in groups Ⅰ,AM1241 and AM630 (P ＜ 0.05).Compared with group Ⅰ,the cell viability was significantly increased,and the release of LDH was significantly decreased in group AM1241 ( P ＜ 0.05).There was no significant difference in the cell viability and the release of LDH between groups 1 and AM630 ( P ＞ 0.05).Conclusion Glutamate induces microglial injury through inhibiting the function of CB2 receptor.
RESUMEN
Objective To investigate the effect of curcumin on the expression of cannabinoid receptor 1 (CBR1) and NR2B subunit-containing NMDA receptor in spinal cord dorsal horn and dorsal root ganglion (DRG) neurons in a rat model of neuropathic pain.Methods Seventy-two male Sprague-Dawley rats,weighing 200-230 g,were randomly divided into 4 groups ( n =18 each):sham operation group (S group),chronic constrictive injury (CCI) group,curcumin group (Cur group) and solvent control group (SC group).Neuropathic pain was induced by CCI.The sciatic nerve was exposed and 4 loose ligatures were placed on the sciatic nerve at 1 mm intervals in groups CCI,Cur and SC.Curcumin was injected intraperitoneally at 100 mg· kg- 1· d-1 for 14 consecutive days after operation in Cur group,while the equal volume of dimethyl sulfoxide was given instead of curcumin in SC group.Mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were measured on 2 days before operation and on 1,3,7,10 and 14 days after operation.Six rats in each group were sacrificed on 3,7 and 14 days after operation and the lumbar segments of the spinal cord ( L4,5 ) and DRGs were removed to determine the expression of CBR1 and NR2B by immuno-histochemistry.Results Compared with S group,MWT was significantly decreased,TWL was significantly shortened,and the expression of CBR1 and NR2B in spinal cord dorsal horn and DRG neurons was up-regulated after operation in the other three groups (P ＜ 0.05 ).Compared with CCI group,MWT was significantly increased,TWL was significantly prolonged,the expression of CBR1 inspinal cord dorsal horn and DRG neurons was up-regulated,and the expression of NR2B in spinal cord dorsal horn and DRG neurons was down-regulated after operation in group Cur (P ＜ 0.05 ),and no significant change in the parameters mentioned above was found in group SC ( P ＞ 0.05 ).Conclusion Curcumin can alleviate neuropathic pain in rats,and up-regulation of CBR1 expression and down-regulation of NR2B expression in spinal cord dorsal horn and DRG neurons are involved in the mechanism.
RESUMEN
BACKGROUND/AIMS: This study was designed to investigate the possibility that the enhanced nociceptive responsiveness associated with canabonoid type 1 receptors (CB1Rs) and identify its role in mediating visceral hypersensitivity induced by chronic restraint stress. METHODS: Rats were exposed to daily partial restraint stress or sham partial restraint stress with intraperitoneal injection of the vehicle, CB1R agonist or antagonist for 4 consecutive days. We tested the visceromotor reflex to colorectal distention at day 0 and 5. Reverse-transcription polymerase chain reaction and Western blot were used to assess the expression of CB1Rs. RESULTS: Intraperitoneal CB1 agonist (ACEA) injection significantly diminished (p < 0.05) the enhanced visceromotor reflex to colorectal distention at day 5 in stressed rats. Change in electromyogram response after ACEA over baseline, at pressure of 40 mmHg (+13.3 +/- 2.2), 60 mmHg (+15.3 +/- 2.8) and 80 mmHg (+17.0 +/- 4.0) were much lower than in the control animals, which were +35.9 +/- 5.1, +41.1 +/- 6.3 and +54.1 +/- 9.6, respectively. Whereas, CB1 antagonist (SR141716A) had an opposite effect. Compared with control group, the change in electromyogram response after SR141716A over baseline was significantly enhanced (p < 0.05) for the distending pressure of 40 mmHg (+56.0 +/- 10.3), 60 mmHg (+74.6 +/- 12.3) and 80 mmHg (+82.9 +/- 11.0), respectively. Reverse-transcription polymerase chain reaction and Western blotting demonstrated the stress-induced up-regulation of colon CB1Rs (p < 0.05). CONCLUSIONS: Our results suggest there is a key contribution of peripheral CB1Rs involved in the maintenance of visceral hyperalgesia after repeated restraint stress, providing a novel mechanism for development of peripheral visceral sensitization.
Asunto(s)
Animales , Ratas , Western Blotting , Colon , Hiperalgesia , Hipersensibilidad , Inyecciones Intraperitoneales , Síndrome del Colon Irritable , Negociación , Piperidinas , Reacción en Cadena de la Polimerasa , Pirazoles , Receptor Cannabinoide CB1 , Receptores de Cannabinoides , Reflejo , Salicilamidas , Regulación hacia ArribaRESUMEN
Objective To explore the molecular mechanism of glucocorticoid (GC)-induced osteoporosis (GIOP). Methods Thirty-two female SD rats after matching body weight were divided randomly into three groups: baseline group (n = 10), control group (n = 11) and GC-treated group (n = 11). The administration time was 9 weeks. Bone mineral density (BMD) was measured with dual energy X-ray absorptiometry. A high resolution micro-CT was used to quantify the densitometric and microarchitectural properties of trabeculae in the proximal metaphysis of right tibia. In situ hybridization histochemistry and immunohistochemistry were used to detect the expression of cannabinoid type 1 receptor (CBI R) in the proximal metaphysis of left tibia. Results At the end of the experiment, whole-body BMD in vivo in the control group [(0. 156±0. 008) g/cm2]was higher than that in the baseline group [(0.147±0.006)g/cm2], while the whole-body BMD in vivo [(0.147±0.006) g/cm2]and total BMD in vitro at femurs in the GC-treated group [(0.220±0.011) g/cm2]was lower than those in the control group [(0. 240±0. 024)g/cm2]. Compared with the baseline group and control group, there was a remarkable decrease in the volumetric BMD, tissue BMD, trabecular number and trabecular connectivity (P<0.05) in the GC-treated group, while there was a significant increase in trabecular separation (P < 0. 05) and trabecular thickness also increased in the proximal metaphysis of tibiae in the GC-treated group. The expression level of CB1R mRNA and protein in osteoclasts in the GC-treated group was markedly higher than that in the baseline group and control group (P < 0. 05). There was a close correlation between the expression level of CB1R mRNA, protein in osteoclasts and some microarchitectural parameters in the proximal metaphysis in the GC-treated group (P<0.05). Conclusions The administration of GC is associated with a decrease in BMD and deterioration in microarchitecture of trabecular bone in rats tibiae. Glucocorticoid may up-regulate the CB1R expression level in osteoclasts and this may be a kind of molecular mechanism of GIOP.
RESUMEN
Objective To study the expression and distribution of CB2 in rat skin tissue. Method Immunohistochemistrial technics were employed to study the expression and distribution of CB2 in rat skin tissue. Results CB 2 receptors mostly presented in suprabasal layers of the epidermis and hair follicles in dermis by CB2 like immunoreactivity with a N terminal anti CB2 receptor antibody. The positive expression of CB2 appeared in rat spleen and a negative result occured in liver. Conclusion The CB2 receptors distributed mainly in the rats, epidermis and hair follicles, may involve in some of the dermic physiological and pathological process, such as the communication between central neural system and skin.