Immunohistochemical localization of eight phospholipase C isozymes in pancreatic islets of the mouse

Abstract

The possible involvement of phospholipase C (PLC) in the regulation of insulin secretion is not clearly understood and neither its isozymes expressed nor cellular localization in the pancreatic islets is known. By using specific monoclonal antibodies, we have investigated the expression and localization of eight different PLC isozymes, β1, β2, β3, β4, γ1, γ2, δ1, and δ2, in the pancreatic islets of adult mice. Immunohistochemical analysis carried out on paraffin embedded sections showed a distinct pattern of expression for each of the PLC isozymes. In the central part of the islets containing β cells, a high level of β4 and moderate levels of β3 and γ1 were expressed, whereas PLC-β1 and -γ1 were abundantly expressed in the exocrine pancreas. These results demonstrated the heterogeneity in expression of the phospholipase C isozymes in pancreatic islets. It is conceivable that these isozymes are coupled to different receptors and perform selective tasks in the regulation of insulin secretion for glucose homeostasis.