Lectin-bindings in pituitary adenomas and normal pituitaries.

The first study was undertaken for detecting hormone-receptors for estrogen and progesteron with immunohistochemical methods in frozen sections of 58 pituitary adenomas of different types. In all cases the result was negative. In the second study we tested the binding pattern for the lectins Peanut lectin (PNA), Ulex europaeus agglutinin (UEA-1) and the Concanavalin agglutinin (Con-A) in 144 pituitary adenomas of different types and in 20 post-mortem pituitaries using the two-layer indirect technique. All normal pituitaries reacted positive for all three lectins, elsewhere the binding feature for pituitary adenomas was different. Via statistical analysis, correlating lectin-bindings with clinical hyperfunction and immunohistochemical hormone content, we found an association of acromegaly and PNA and ConA and of Cushing's disease and PNA and UEA-1; furthermore of GH and UEA-1 and Con-A, of TSH and UEA-1 and of ACTH and PNA and UEA-1. Using serial sections (AB-method for demonstrating hormones and two layer indirect technique for lectin-binding) and the double-staining technique (labelled Streptavidin-Biotin-method for demonstration of hormones and the two-layer indirect technique for lectins) we found Con-A reacting with GH and PRL cells and with a part of FSH-cells, UEA-1 reacting with most of the ACTH-cells and PNA reacting with FSH-cells.