Sex Differences Of Depression Related To Monoamine Metabolism And Suicidal Behavior

Objective：To investigate the sex difference of depression associated with5-hydroxytryptamine transporter（5-HTT）, norepinephrine transporter（NET）, and monoamine oxidase B（MAO-B）, as well as suicidalbehavior in CUS-induced rats and clinical depression patients.Methods：1.60SD rats (30for each male and female) were randomly dividedinto following groups：male control group（MCG），male model group（MMG），female control group（FCG) and female model group（FMG）.Chronically unpredicted stress（CUS） plus solitary condition was taken toestablish rat depression model.2. The open-field tes（tOFT） and forced swimming test （FST）wereused to evaluate the behavioral changes of experimental rats.3. The pathological changes of hippocampus were observed bymicroscope with HE-staining slices.4. The mRNA and protein expressions of MAO-B and5-HTT in hippocampus and NET in pons were determined by Real-time fluorescentquantitative PCR and Western blot(WB), respectively.5. English and Chinese databases such as CNKI, PubMed weresearched to obtain suicidal case data with depression, which was filtered inaccordance with certain criteria and analyzed with Meta.Results：1. There exised significantly decreasing locomotor activity in OFT andincreasing immobility time in FST from MMG and FMG rats, in comparisonwith corresponding control, and the behavioral changes of MMG rats weremuch more obvious than that of FMG.2. Compared with corresponding control groups, clear karyopyknosisand hyperchromatism of hippocampal neurocytes were observed in bothMMG and FMG. The severity of cellular injury in MMG seemed to bemuch more serious than that in FMG.3. Expressions of obviously decreased5-HTT and elevated MAO-Band NET also were found in both model groups vs corresponding control,and NET expression was clearly higher in MMG than that in FMG.4. The odds ratio of total suicidal behavior (male patients:femalepatients) was0.94,(95%confidence interval：0.63—1.12，P=0.23)， oddsratio of suicide success was0.84,(95%confidence interval：0.18—5.07，P=0.94)，and odds ratio of attempted suicide was0.75,(95%confidence Conclusion：CUS-induced depression-like behaviors is much more serious inmale rats than in female rats，which may be at least partly related to thedifferent expressions of MAO-B,5-HTT and NET. There is certainly agender difference in depression patients with suicidal behavior; incidenceof suicide attempt in male depression patients is significantly higher thanfemale.