The effects of captopril on lipopolysaccharide-induced sickness behaviors in rats

Neuro-immune mediators play an important role in the development of sickness behaviors. In the present study, the effect of captopril on sickness behaviors caused by lipopolysaccharide (LPS) was studied in the rats. The animals were randomized into the following groups: control, sham, ۱۰ mg kg-۱ captopril - LPS (Capto ۱۰-LPS), ۵۰ mg kg-۱ captopril - LPS (Capto ۵۰-LPS), and ۱۰۰ mg kg-۱ captopril - LPS (Capto ۱۰۰-LPS). Behavioral tests including open-field (OF), elevated plus maze (EPM) and forced swimming (FS) test were performed, and the serum level of interleukin-۶ (IL-۶) was assessed. In OF, the number of crossings in the central zone in Capto ۱۰-LPS, Capto ۵۰-LPS, and Capto ۱۰۰-LPS groups was higher than that of the sham group. In EPM, the open arm entry numbers in the sham group were lower compared to the control group. Furthermore, pretreatment by captopril increased the entries to the open arms. In FS test, the immobility time of the sham group was longer than that of the control group. In Capto ۱۰-LPS, Capto ۵۰-LPS, and Capto ۱۰۰-LPS groups, immobility was shorter compared to the sham group. In addition, the IL-۶ level was higher in the sham group compared to the control group, and treatment with ۵۰ and ۱۰۰ mg kg-۱ of captopril restored the IL-۶ level in comparison with the sham group. Results confirmed that pretreatment with captopril ameliorated LPS-caused sickness behaviors and attenuated IL-۶ as an inflammatory marker in the rats.

Keywords:

Captopril , Interleukin-۶ , Lipopolysaccharide , Rat , Sickness behavior