Pituitary adenylate cyclase-activating polypeptide ameliorates vascular dysfunction induced by hyperglycaemia

Background:Short-lasting hyperglycaemia occurs frequently in prediabetes and poorly controlled diabetes mellitus leading to vascular damage. Pituitary adenylate cyclase-activating polypeptide (PACAP) has been shown to play a protective role in vascular complications of diabetes; moreover, antioxidant effects of PACAP were also described. Therefore, we hypothesized that PACAP exerts protective effects in short-term hyperglycaemia-induced vascular dysfunctions.Methods:After short-term hyperglycaemia, acetylcholine-induced and sodium nitroprusside–induced vascular relaxation of mouse carotid arteries were tested with a myograph with or without the presence of PACAP or superoxide dismutase. Potential direct antioxidant superoxide-scavenging action of pituitary adenylate cyclase-activating peptide was tested with pyrogallol autoxidation assay; furthermore, the effect of pituitary adenylate cyclase-activating peptide or superoxide dismutase was investigated on hyperglycaemia-associated vascular markers.Results:...