Selective inhibition of NADPH oxidase reverses the over contraction of diabetic rat aorta.

Abnormal vascular responsiveness in diabetes has been attributed to a number of changes in contractile pathways, affected in part by the overproduction of reactive oxygen species (ROS). It has been reported that NADPH oxidase (NOX) is increased in diabetic (streptozotocin treated; STZ) rat arteries; however the pharmacological agents used to inhibit NOX activity are known to be unsuitable for in vitro studies and have a high level of non-selectivity. Here we have used the highly selective NOX inhibitor VAS2870 in diabetic rat aorta and compared its effects with apocynin, SOD, and allopurinol on phenylephrine and U46619 induced contraction.

A method for characterising cell death in vitro by combining propidium iodide staining with immunohistochemistry.

The fluorescent exclusion dye propidium iodide (PI) is widely used as a vital dye in tissue culture systems and labels the nucleus in dying cells which lack an intact plasma membrane. We have developed a method, which allows the preservation of the PI signal in paraformaldehyde-fixed tissue, enabling subsequent immunohistochemical characterisation of labelled cells. We have tested this method in a model of ischemia based on oxygen and glucose deprivation in organotypic hippocampal slice cultures, in combination with immunocytochemical detection of calpain-I mediated spectrin breakdown products (BDPs).