Lectin histochemical investigations of fetal cultivated pancreatic tissue.

Abstract

The terminal glycoproteins of fetal, cultivated (7-12 days), and adult nondiabetic and diabetic pancreatic tissues (Balb c, C3h mice) were investigated by lectin histology (peanut-, phytohemagglutinin, wheat germ agglutinin, Ulex europeus I, concanavalin A and Ricinus communis agglutinin, PaP method +/- neuraminidase). Anti-insulin and -glucagon were used to identify islet cells. S-100 antibody showed dendritic reticulum cells, anti-IAK proved MHC II antigens (C3h). Cultured tissue was partly incubated with anti-IAK and complement for lysis of MHC II antigens. On the 19th gestational day fetal pancreatic tissue did not bind peanut agglutinin, Phytohemagglutinin, or wheat germ agglutinin, whereas concanavalin A and Ricinus communis were weakly bound. Terminal fucose residues were not expressed by C3h fetal islet cells in contrast to Balb c. Following neuraminidase digestion peanut agglutinin and phytohemagglutinin were strongly bound, indicating sialic acid-substituted terminal glycoproteins. Cultivated tissue (Day 7) bound all investigated lectins (except Ulex europeus I in C3h mice), indicating maturation of islet cells. In spite of the peak of insulin concentration in the medium we observed a faint binding of anti-insulin and investigated lectins following 12 days of cultivation. This indicates a disorder of terminal glycoprotein synthesis at this point. There was no difference in lectin binding patterns of adult nondiabetic islet cells compared to the cultivated tissue (7 days), but no Ulex europaeus I binding of the adult Balb c mice was observed. S-100 binding decreased during the cultivation period as dendritic reticulum cells became destroyed by cultivation.(ABSTRACT TRUNCATED AT 250 WORDS)