[Morphology and function of the human spleen. Enzyme histochemical and electron microscopy studies of the splenic lymphatic vessels, nerves and connective tissue structures].

Many questions concerning the morphology of the spleen have been cleared up in the last 20 years by the application of new methods of investigation, especially electron microscopy and enzyme histochemistry. With but a few exceptions, however, only the splenic parenchyma (the red and white pulp) were studied. Such special structures of the human spleen as nerves, lymphatic vessels and their supporting tissue, which may play an important role in the coordination and integration of the different functions of the white pulp (secondary lymphatic organ) and the red pulp (blood filter), were hardly ever studied with modern techniques. Investigating these structures light and electron microscopically and enzyme histochemically it was attempted to complete our present knowledge of the histology of the human spleen. In addition, by comparing the study of special altered spleens with experimental data it was attempted to clarify the importance of these structures for the physiology and pathology of the spleen. A total of 151 normal and pathologically altered spleens from the bioptic and autopsy material of the Pathological Institute of the University of Kiel were examined. In addition to conventional light microscopy the spleens were investigated enzyme histochemically and cytochemically, fluorescence microscopically and electron microscopically. The following enzyme reactions were done: Alkaline and acid phosphatase, alpha-naphthylacetate-esterase, naphthol-AS-acetate-esterase, 5'-nucleotidase, ATPase, and acetylcholinesterase. The various enzyme reactions were sometimes done in combination and reticulum and collagenous fibers were investigated by a subsequent staining of argyrophilic fibers. The fine localization of the 5'-nucleotidase activity was studied ultrahistochemically. Adrenergic nerve fibers were investigated fluorescence microscopically using the glyoxylic acid method.