Immunohistochemistry on rodent circulatory system: Its possible use in investigating hypertension

Considering the increasingly strong footing of the role of vascular wall inflammation in hypertension, immunohistochemistry has become an important method to investigate the inflammatory responses in circulatory system. Immunohistochemistry is a method used to recognise the presence and location of constituents of tissues (as antigens) in situ by means of corresponding labelled antibodies. The principle of immunohistochemistry lies on the immunoreaction between antibodies to bind specifically to their corresponding antigens. Since it is done on a tissue rather than measuring inflammatory biomarker levels in serum, immunohistochemistry gives an overview of an intact tissue in the aspect of the localisation of a particular protein (i.e. in nucleus, cellular membrane or cytoplasm) and thus the expressions of inflammatory biomarkers may indicate what they are doing in vivo. In addition, the continuing advance in computer-aided image analysis has shifted immunohistochemistry from a traditional ‘merely descriptive’ technique to a quantitative measurement. Digital image evaluation enables measurements of protein activation by quantifying the colour density of positive immunostaining on a tissue. Therefore, immunohistochemistry is advantageous in providing not only qualitative but also semi-quantitative or quantitative information of protein expressions.