Immuno‐enzymatic detection of fibronectin in normal and pathological haematopoietic tissue

Abstract

Cryostat sections of bone marrow biopsies were stained immuno-enzymatically for fibronectin using the alkaline phosphatase:anti-alkaline phosphatase (APAAP) technique. In normal marrow fibronectin was present only in megakaryocytes and the walls of blood vessels. Myelofibrotic bone marrow possessed an extensive distribution of fibronectin which did not correspond to the distribution of reticulin. Infiltrated and hypercellular marrows showed an increase in fibronectin which appeared to be related to increased marrow vascularity. Again no correlation with the reticulin pattern was evident. In contrast to platelets, other circulating blood cells had no demonstrable fibronectin. Fibronectin apparently does not act as a mediator of hemopoiesis in vivo as was suggested by the results of experiments in non-human models.