The histochemical detection of glycoconjugate deposition with lectins.

The deposition of glycoconjugates in human brain tissue was investigated in cases with or without psychiatric disorders using histochemical techniques with lectins conjugated with peroxidase or biotin, antibodies against beta-amyloid and component P, and conventional staining methods. In addition, visualization of senile plaques and neurofibrillary tangles was performed with Con A, PSA, and/or deposits in the brain. One type of structure, known as the corpora amylacea, was stained by Con A, UEA-I, DBA and GSA-I-B4 lectins, and conventional stains such as hematoxylin-eosin, periodic acid Schiff, aldehyde fuchsin and alcian blue staining techniques. The other types of deposits were newly found in this study and were not stained by conventional and immunohistochemical staining methods. Perivascular type depositions were mainly found in patients with Alzheimer type dementia and showed remarkable reactivity with PSA, Con A, UEA-I, GSA-I-B4, DBA, PNA, SBA and ECA lectins. Spherical type depositions were mainly found in the hippocampal formation in cases of schizophrenia and stained by UEA-I, GSA-I-B4 and DBA lectins. The findings obtained in this study indicate that a dynamic balance between the activity of glycosyltransferases and relevant glycosidases might be important in the development of human brains, and degenerational changes such as depositions in the brain might result from a discordant glycometabolism. The lectin staining technique is a useful tool for the postmortem diagnosis of brain disorders. [ABSTRACT FROM AUTHOR]