Histotopographic and ultrastructural study on the lymphatic network of the pancreas in the guinea pig

The localization of absorbing lymph vessels was studied in the normal guinea pig pancreas by light microscopy (serial semithin sections) and transmission electron microscopy (ultrathin sections). Absorbing lymph vessels were observed both in the interlobular and intralobular areas where they can be localized close to the adenomeres. Lymph vessels were also seen in the interlobular areas located next to the islets of Langerhans and to groups of endocrine cells (n = 8-10) not showing a vascular organization comparable with islets of Langerhans. All lymph vessels in the pancreas are absorbing lymph vessels, characterized by a very thin endothelial wall, anchoring filaments and the absence of a definitive basal membrane. Adjacent endothelial cells form end-to-end, overlapping and interdigitating intercellular junctions. Valves were present both in the interlobular and intralobular lymph vessels.