Background:Psychocardiological researches have suggested a central role of 5-hydroxytryptamine (5-HT) on psychocardiological mechanism.This study aimed to further explore the central role of 5-HT and pretreatment effects of XinLingWan on rats with myocardial infarction (M I) and/or depression.Methods:Ninety Sprague-Dawley rats were randomly divided into three groups:MI group,depression group,and MI + depression group (n 30 in each group).Each group was then divided into three subgroups (n =10 in each subgroup):a negative control subgroup (NCS),a Western medicine subgroup (WMS),and a traditional Chinese medicine subgroup (TCMS),which were received pretreatment once a day for 4 weeks by saline,20 mg/kg sertraline mixed with 2 ml saline,and 40 mg/kg XingLingWan mixed with 2 ml saline,respectively.Different rat models were established after different pretreatments.Rats were then sacrificed for detection of serum 5-HT,platelet 5-HT,5-HT2.A receptors (5-HT2AR),and serotonin transporter (SERT).Data were analyzed by one-way analysis of variance (ANOVA) and least-significant difference (LSD) testing.Results:M I group:compared with NCS,there was a significant increase in WMS and TCMS of serum 5-HT (176.15 ± 11.32 pg/ml vs.334.50 ± 29.09 pg/ml and 474.04 ± 10.86 pg/ml,respectively,both P =0.000),platelet 5-HT (129.74 ± 27.17 pg/ml vs.322.24 ± 11.60 pg/ml and 340.4 5 ± 17.99 pg/ml,respectively,both P =0.000);depression group:compared with NCS,there was a significant increase in WMS and TCMS of serum 5-HT (194.69 ± 5.09 pg/ml vs.326.21 ± 39.98 pg/ml and 456.33 ± 23.12 pg/ml,respectively,both P =0.000),platelet 5-HT (175.15 ± 4.07 pg/ml vs.204.56 ± 18.59 pg/ml and 252.03 ± 22.26 pg/ml,respectively,P =0.004 and P 0.000,respectively);MI + depression group:compared with NCS,there was a significant increase in both WMS and TCMS of serum 5-HT (182.50 ± 10.23 pg/ml vs.372.55 ± 52.23 pg/ml and 441.76 ± 23.38 pg/ml,respectively,both P =0.000) and platelet 5-HT (180.83 ± 11.08 pg/ml vs.221.12 ± 22.23 pg/ml and 265.37 ± 29.49 pg/ml,respectively,P =0.011 and P =0.000,respectively).Conclusions:By elevating the amount of 5-HT and modulating 5-HT2AR and SERT levels in serum and platelets,XinLingWan and sertraline were found to exert pretreatment effect on rat models of MI and/or depression.