Distributional patterns of phospholipase C isozymes in rat pancreas

Phospholipase C (PLC) isozymes are believed to play a role in regulating pa ncreatic exocrine and endocrine secretion. in an attempt to investigate the role of PLC, we examined the distribution patterns of PLC isozymes in the normal rat pancreas by Western blot analysis and immunohistochemistry. West ern blot analysis was performed on pancreatic acinar tissues and the islet of Langerhans, which were separated from each other. PLC-beta isozymes (bet a1, beta2, beta3, and beta4), delta1, and delta2 were detected in both acin ar and islet cells, whereas PLC-gamma1 and gamma2 were observed only in aci nar tissues. On immunohistochemistry, the immunoreactivities of PLC isozyme s except fur PLC-gamma1 were observed as follows: PLC-beta1, in both the ex ocrine and endocrine tissues; PLC-beta2, mainly in the periphery of the isl et and acinar cells; PLC-beta3, in the periphery of the islet and in some d uctal epithelium; PLC-beta4, through the islet of Langerhans and ductal epi thelium; PLC-gamma1, not. detected in pancreatic tissue; PLC-gamma2, mainly in acinar cells; PLC-delta1 and delta2, in the islet and in ductal epithel ium. These results suggest that the intrapancreatic site-specific existence of PLC isozymes may modulate pancreatic exocrine and endocrine functions t hrough a PLC-mediated signal transduction.