ELECTRON MICROSCOPIC STUDY OF 5'-NUCLEOTIDASE IN GERMINAL CENTRES OF HUMAN TONSILS

Activity of 5′-nucleotidase within germinal centres of human tonsils has been investigated with the electron microscope. Tonsils were fixed in glutaraldehyde and incubated according to the method of Wachstein and Meisel. The percentage of positively reacting germinal centre cells was all together small. All types of germinal center cells can show 5 nucleotidase - activity (lymphocytes, germinocytes, germinoblasts, rarely plasmacells). The reaction product was deposited on the outer or inner face of the plasma membrane. This finding is in accordance with the results of other authors obtained in cell-types from other tissues. In contrast to light microscopical observations, activity of adenosintriphosphatase was also demonstrated on the plasma-membranes. As all cell-types can give a positive reaction, the demonstration of 5′-nucleotidase cannot be used for marking one specific cell-type within the germinal centres. © 1969 Springer-Verlag.