Surface ultrastructure of human leucocytes, mouse macrophages and rat liver cells, and of isolated nuclei and nucleoli.

Abstract

Summary. Examination of preparations from the human, rat and mouse with special reference to white blood cells, using the Cambridge Stereoscan Electron Microscope, showed that there is almost certainly a characteristic surface appearance of cells, nuclei and nucleoli from various tissues.The most important findings were: The experiments concerning non‐specific stimulation of mouse peritoneal macrophages showed that this technique was suited to demonstration of subtle dynamic changes in the cell surface membrane. The technique has already been employed in a similar respect with regard to the red cell. It was possible for the first time to look at the inner aspect of nuclear membrane at ultrastructural levels in three dimensions. While it would be difficult to draw conclusions from nuclear membranes disrupted by electron bombardment, examination of the lymphocyte nuclear membrane resulting from ultrasonic disintegration showed that the external surface appearances had been preserved and were similar to those of intact lymphocyte nuclei. Comparison of white cell nuclei and nucleoli with rat liver nuclei and nucleoli revealed marked differences. The surface irregularity of the liver nuclei was never seen in white cell nuclei and the liver nucleoli were of individual character. An opportunity is presented for comparing the surface changes in these structures during the numerous experimental procedures carried out on rat liver and equating these with cellular function. The granular white cells and their precursors were disappointing in their surface characteristics and it was impossible to identify the individual members of the series. In contrast the surface identity of the lymphocyte is of importance, since a method is now available for exhibiting the membrane changes which are known to occur from immunological causes. Work is currently being carried out to detect and evaluate such changes.