Immunohistochemical localization of phospholipase A2 in the guinea pig nasal mucosa.

OBJECTIVE Phospholipase A2 (PLA2) is a key enzyme in arachidonic acid metabolism, which is involved in the maintenance of biological homeostasis and the onset of various diseases. The immunohistochemical localization of PLA2 in the nasal mucosa has not been reported, even though the presence of messenger RNA of PLA2 has been demonstrated in the human nasal brush sample. The present study was designed to determine the localization of PLA2s in the nasal cavity. METHODS The immunohistochemichal localization of secretory PLA2 (sPLA2) and cytosolic PLA2 (cPLA2) in the nasal mucosa was studied using adult guinea pig. RESULTS Both sPLA2 and cPLA2 were localized in the nasal gland as well as the respiratory epithelium, and not in the surrounding vascular endothelial cells, olfactory gland, olfactory epithelium or submucosal tissue. CONCLUSION Our data provide the first convincing evidence that both sPLA2 and cPLA2 are significantly expressed in the nasal gland and the respiratory epithelium, and are suggested to regulate the function of the nasal mucosa, such as bactericidal, Na secretion, and allergic response.