The Role of Epoxyeicosatrienoic Acids in Diabetes Mellitus-Induced Impaired Vascular Relaxation of Aortic Rings in Ovariectomized Sprague-Dawley Rats

Figure 2

Mechanisms of acetylcholine-induced relaxation (AChIR) response of isolated rat aorta rings in non-OVX-CTR and non-OVX-DM rats. (a) and (b) present the relaxation of isolated aortic rings in response to ACh (presented as log [ACh] of ACh concentration (10^-9 to 10^-5 M)) in the non-OVX-CTR (a) and non-OVX-DM (b) groups of rats. The presence of L-NAME and MS-PPOH significantly reduced the AChIR of isolated rat aortic rings in the non-OVX-CTR group (a) and non-OVX-DM group (b) of rats. Indomethacin administration did not have any significant effects on AChIR in both the non-OVX-CTR (a) and non-OVX-DM (b) groups of rats. Data were compared by two-way ANOVA and Bonferroni post hoc tests. Sensitivity to ACh in the presence of L-NAME and MS-PPOH was significantly decreased compared to the basic response or response to ACh in the presence of Indomethacin in both the non-OVX-CTR and non-OVX-DM groups of rats. LogEC50 values were compared by one-way ANOVA followed by Holm-Sidak pairwise multiple comparison. Statistically significant () AChIR in the presence of L-NAME () or MS-PPOH (^†) compared to the baseline ACh response. : ^‡L-NAME vs. baseline, Indomethacin, and MS-PPOH; ^§MS-PPOH vs. baseline and Indomethacin. Concentrations—ACh: 10^-9 to 10^-5 mmol L^-1, L-NAME:  mmol L^-1, Indomethacin: 10^-5 mmol L^-1, and MS-PPOH: 10^-5 mmol L^-1. : number of aortic rings. EC50 (mol L^-1): half maximal effective concentration presents the concentration of ACh (mol L^-1) which induces a response halfway between the baseline and maximum.

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