A Study On The Correlation Between Plasma Nociceptin/Orphanin FQ And Affective Disorder

ObjectiveTo investigate the pathogenesis and diagnosis of affective disorder through studying the changes of plasma nociceptin/orphanin FQ(OFQ) level in patients with affective disorder.MethodsThis is a case-control study.24 patients with major depressive disorder(MD group),21 patients with bipolarâ…¡disorder(BD group),26 patients with bipolarâ… disorder(BM group) and 31 healthy volunteers(control group) were studied.All the subjects were tested by a self-made general information questionnaire.The MD patients and the BD patients were assessed by Hamilton Depression Scale(HAMD) and Montgomery and Asberg Depression Rating Scale(MADRS).The BM patients were assessed by Bech-Rafaelsen Mania Rating Scale(BRMS).2ml of venous blood samples were collected into tubes containing EDTAK₂ at 7 am.Gently rock the tubes several times immediately after collection of blood for anti-coagulation.Transfer the blood to centrifuge tubes containing aprotinin(0.6 TIU/ml of blood) and gently rock several times to inhibit the activity of proteinases.Centrifuge the blood at 1,600×g for 15 minutes at 4℃and collect the plasma.Plasma samples were kept at -70℃.The plasma OFQ concentrations were measured by a commercial radio immunoassay kit. All statistical analyses were performed using SPSS 13.0 software.Two-sample/group t-test for independent samples,one-way ANOVA and Spearman rank correlation analysis were applied in this study.Results1.The plasma OFQ concentrations were(17.20±4.13)ng/L in MD group, (20.16±3.58)ng/L in BD group,(11.29±3.28)ng/L in BM group and(13.92±4.53)ng/L in control group.Compared with the control group,the levels of plasma OFQ in MD and BD group were higher(t=2.76,t=5.28;P＜0.01),while the level in BM group was lower(t=-2.47,P＜0.05).The differences were statistically significant.2.Gender and OFQ level:There were no significant statistical differences between genders in each group(P＞0.05).3.Correlation between plasma OFQ levels and the scores of the scales:The levels of plasma OFQ in MD group were positively correlated to the total scores of HAMD and MADRS(r=0.598,P＜0.01;r=0.646,P＜0.01).The plasma OFQ levels in BD group were also positively correlated to the total scores of HAMD and MADRS(r=0.607,P＜0.01;r=0.541,P＜0.05).And there was a significantly negative correlation between OFQ levels and the total scores of BRMS in BM group(r=-0.750,P＜0.01).Conclusions1.Plasma OFQ level was thought to be correlated with affective disorder.2.Gender is not a factor which affects the level of plasma OFQ.3.Plasma OFQ may be a new biological parameter used to estimate the severity of affective disorder.4.OFQ-NOP receptor system may put impacts on the pathogenesis of affective disorder and be a novel potential target of antidepressant drug or mood stabilizer development.