DISTRIBUTION OF INTEGRIN-LIKE IMMUNOREACTIVITY ON PRIMATE BRAIN MICROVASCULATURE

The objective of this immunohistochemical study was to detail the dist ribution patterns of alpha and beta integrin subunit expression in non -ischemic non-human primate brain in comparison to that reported for r odents and humans. For this purpose cerebral specimens were obtained f rom 3 adolescent male baboons by direct perfusion and immediate proces sing. Well-characterized monoclonal and polyclonal antibodies against human alpha and beta integrin subunit antigens were used to define the ir location and distribution relative to the markers for vascular basa l lamina, laminin (LM). and astrocytic fibers or glial fibrillic acid protein (GFAP). Quantitation of microvascular epitopes required comput erized videoimaging microscopy and laser confocal microscopy (LCM). Ea ch subunit was categorized into one of four microvascular patterns rel ative to LM antigen: (a) all microvascular diameter categories-alpha(1 ), alpha(nu), and beta(1); (b) antigen-sparing capillaries alpha(2), a lpha(1), alpha(5), alpha(v) and beta(3); (c) a subset of all microvasc ular diameter classes-alpha(3) beta(4), and beta(5); and (d) no antige n apparent, beta(2). Subunit antigens alpha(1), alpha(2), beta(1), and beta(5) were detected on perivascular astrocytes. Subunits alpha(1), and beta(1), and GFAP colocalized (LCM). This quantitative survey deta iled specific microvascular and astrocyte associations of certain alph a and beta integrin subunits in non-human primate brain. Specific repr oducible and consistent distributions of alpha and beta subunits form the basis for further investigation of their responses to focal ischem ia in a human relevant system.