[Role of human spleen in the release and sequestration of white blood cells]

In 21 patients during operation blood samples were obtained from splenic vein and artery immediately before splenectomy for determination of qualitative and quantitative composition of white blood cells to establish the role of the spleen in their release and sequestration. It was found that the spleen released into circulation mononuclear cells whose number, size of nucleus and glycogen content of the cytoplasm varied individually in various cases. Besides that the spleen releases and sequestrates granulocytes, most probably as a result of intravascular shifts in the marginal and circulating cell pools induced, among others, by contractions of the spleen.