Nicergoline improves the depressive behavior of vascular depression in rats by regulating monoamine neurotransmitter receptors expression in hippocampal CA1 region and serum apolipoprotein E4 level / 国际脑血管病杂志

ABSTRACT

Objective To investigate the effects of nicergoline on expressions of 5-hydroxytryptamine 1A receptor (5-HT1AR), D2 dopamine receptor (D2DR),α2A adrenaline receptor (α2AAR) in the hippocampal CA1 region and the serum level of apolipoprotein E4 (ApoE4) in a rat model of vascular depression (VD) . Methods Forty-eight male Sprague-Daw ley rats w ere randomly al ocated into a normal control group, a model group, fluoxetine group, a low-dose nicergoline group, a medium-dose nicergoline group, and a nicergoline high-dose group ( n=8 in each group). A rat model of VD w as induced by the ligation of bilateral common carotid arteries combined w ith chronic unpredictable mild stress (CUMS) plus single housing. The rats did not conduct CUMS or single housing in the normal control group, and the rats in the model group conducted CUMS and single housing. The rats in the fluoxetine group w ere given fluoxetine 1.3 mg/(kg· d) for gastric lavage for 3 w eeks at the beginning of CUMS and single housing. The rats in the low -, medium-and high-dose nicergoline groups w ere given nicergoline 0.9, 1.9 and 3.8 mg/(kg· d), respectively for gastric lavage for 3 w eeks at the beginning of CUMS and single housing. The normal control group and the model group w ere given equal volume of distil ed w ater for gastric lavage, once a day for 3 w eeks. Depression-like behavior w as evaluated using sucrose solution consumption and open-field test. Immunohistochemical staining and Western blot were used to detect the expressions of 5-HT1AR, D2DR, andα2AAR in the hippocampal CA1 region. Enzyme linked immunosorbent assay w as used to detect serum ApoE4 level. Results Before CUMS, the scores of horizontal and vertical movement and sucrose solution consumption in the model group, the fluoxetine group and each nicergoline group w ere decreased significantly compared w ith the normal control group (al P<0.01);w hile at 21 days after CUMS, those in the fluoxetine group and the nicergoline medium-and high-dose groups w ere significantly higher than those in the model group (al P<0.05). There w ere no significant differences betw een the fluoxetine group and each nicergoline group. The expression levels of 5-HT1A R, D2DR, α2A AR, and the serum ApoE4 in the model group, the fluoxetine group, and each nicergoline group w ere significantly higher than those in the normal control group. Those of the fluoxetine group and the nicergoline medium -and high-dose groups were significantly lower than the model group (al P<0.01), while there were no significant differences betw een the fluoxetine group and each nicergoline group. Conclusions Nicergoline can improve the depression-like behavior in VD rats. Its mechanism may be associated w ith the dow nregulation of 5-HT1AR, D2DR, α2AAR expressions and serum ApoE4 level.