Elektronenmikroskopische Untersuchungen zur experimentellen Insulitis nach Injektion von Anti-Insulin-Serum

Electronmicroscopical studies were carried out on mice made hyperglycemic by means of anti-insulin serum. The sera were separated into pools with a high or a low titer of the antibodies. The following observations were made: 1. After a single injection of an antiserum abundant microvesicles are found in the Golgi region. Furthermore, numerous pregranules are noted during the course of regranulation. The possibility of an increased secretion of proinsulin is discussed. 2. After a single as well as repeated injections of strong antiserum highly degenerative changes are noted in some beta cells. It is suggested that a reversible hypersecretory degeneration is present, resulting in a nearly complete inhibition of the secretion. 3. The infiltrate of granular leukocytes observed after administering anti-insulin serum may be considered an immune reaction of the immediate type by the demonstration of precipitated material in the islet area. The occurrence of mononuclear cells in the long term study indicates that in addition a delayed hypersensitivity against the antigen-antibody complex may develop.