Bradykinin

Vascular assessment was conducted as described previously [20 (link),21 (link)]. In brief, human omental arteries were dissected from surrounding connective tissue and mounted on the 620 M Wire Myograph (Danish Myo Technology, Hinnerup, Denmark). A Krebs salt solution (heated to 37 °C) filled the chambers, which were continuously bubbled with carbogen (95% oxygen, 5% carbon dioxide). Using the DMT normalization module on LabChart software (ADInstruments, Bella Vista, NSW, Australia), arteries were normalization to 100 mmHg pressure (13.3 kPa, IC/IC100 = 1). The vascular reactivity of each vessel was assessed as previously described [20 (link)]. Using high potassium physiological salt solution (KPSS), vascular smooth muscle reactivity was assessed, and endothelial integrity was assessed using the endothelial-dependent vasodilator, bradykinin (Sapphire Bioscience, Redfern, NSW, Australia).

Human omental arteries 2 mm in length were carefully dissected from surrounding connective and adipose tissue in Krebs physiological salt solution. The dissected arteries were then mounted on the 620 M Wire Myograph (Danish Myo Technology, Hinnerup, Denmark) chambers with 40 µm tungsten wires (Danish Myo Technology). Chambers were filled with Krebs salt solution, heated to 37 °C, and bubbled continuously with carbogen (95% oxygen, 5% carbon dioxide) to buffer the solution. Arteries were normalised to 100 mmHg (13.3 kPa, IC/IC100 = 1) pressure using the DMT normalisation module on LabChart software (ADInstruments, Sydney, NSW, Australia).
Assessment of the vascular reactivity of each vessel was performed as follows. Vessel smooth muscle reactivity was assessed using high potassium physiological salt solution (KPSS; NaCl 25 mM, KCl 50 mM, MgSO₄ 1.2 mM, KH₂PO₄ 1.0 mM, NaHCO₃ 25 mM, D-glucose 11.1 mM, CaCl₂ 2.5 mM). Endothelial integrity was assessed by pre-constricting vessels to the calculated 50–70% of KPSS constriction with a known vasoconstrictor of omental arteries (a thromboxane agonist), U46619 (Sapphire Bioscience, Redfern, NSW, Australia). This was followed by adding a bolus of the endothelial-dependent vasodilator bradykinin (Sapphire Bioscience). Vasorelaxation of 80% was required for the inclusion of the vessel for further use.