The role of nitric oxide (NO) in microvascular permeability is controversial, in part because
the regulation of its endothelial constitutive synthase, eNOS, has been studied in vitro but
not in vivo. Our study was designed to detect the morphologic and functional presence of
eNOS and to test whether eNOS could be phosphorylated by platelet-activating factor (PAF),
an agent that induces hyperpermeability. Immunocytochemistry was applied using human
anti-eNOS antibodies in the hamster cheek pouch (hcp). The hcp microvessels …