Objectives: 

Omega-3 fatty acids (FA) reduce risk of atherosclerosis, development of which is accompanied with inflammatory processes. Abnormalities in cell-cell communication through connexin (Cx) channels (GapJunctions) were found in vascular wall during atherogenesis. Therefore, we monitored the anti-inflammatory effect of FA on expression of Cx40 in rat aorta in relation to vascular relaxation.

Materials: 

In 10-day-lasting experiment, we used adult Wistar rats. They were divided into four groups C – controls, FA – FA intake in dose 30mg/kg/day, LPS – single dose of lipopolysaccharide (LPS, 1 mg/kg, i.p), LPS+FA – endotoxemic rats treated with FA. Cx40 expression was analyzed using Western blot (WB) analysis, confocal immunofluorescence and morphometric analysis. We also studied NO-dependent relaxation of the aorta and its NOS activity, together with biomarkers CRP, MDA and NAGA in plasma. We used Student T-test for statistical evaluation.

Results: 

WB analysis of total Cx40 of LPS group showed a significant increase by 13% compared to C. In LPS+FA, Cx40 expression was decreased by 42% compared to LPS group (p=0.0002). Using immunofluorescent method we found significant changes in Cx40 spatial expression and Cx40 plaque remodeling during inflammation. It was characterized by increased density of Cx40 plaques by 23%, and decreased of plaque area by 33% compare with C in endothelium. Administration of FA to endotoxemic rats decreased density of Cx40 by 51% when compare to LPS group. FA intake improved LPS-induced impairment of NO-dependent relaxation of aorta, while they had not protective effect on NOS activity. FA diet reduced also LPS-induced increase in biomarkers` levels.

Conclusions: 

Our results show that short-lasting FA diet could have protective effects on the function of aorta probably in association with Cx40-GJ communication. Supported by VEGA 2/0108/10.