Granulocytopoiesis in germfree mice.

Abstract

SummaryA comparison of the total number of neutrophils and neutrophil precursors within the humerus of germfree and conventional mice revealed no statistically significant difference between the two groups. The distribution of marrow neutrophils with respect to morphologic type and the number of neutrophils in mitosis were similar in the two groups. There was, however, a slight, but significantly, lower concentration of blood neutrophils in germfree mice as compared to controls. Removal of mice from the germfree environment was associated with a rapid decrease in the number of mature and relatively mature neutrophils in the marrow and with a subsequent increase in potentially mitotic, immature neutrophils, following which the marrow returned to normal. Germfree mice responded to endotoxm administration with an increase in rate of release of neutrophils from the marrow, as do normal mice. It was concluded that in this model system the presence or absence of microorganisms in the environment could not be as...