Bursa of Fabricius: Uptake of Radioactive Particles and Radiotoxic “Sealing” of Bursal Follicles

Abstract

Earlier studies have demonstrated that the avian bursa functions as a site of intense and selective uptake of particles through the tuft epithelium which overlies the follicles (l, 2). The bursa undergoes rhythmic compression in synchrony with respiration and shows slow, peristalsis-like movements which, in addition to a suction reflex elicited by contact of fluids or solids with the anal orifice, provides for a constant exchange of cloacal and bursal contents. These findings and indirect evidence in favor of bacterial mechanisms located in the tuft epithelial covering the bursal follicles (2) led to the postulate that the bursa may be primarily an immunologic contact organ where lymphoid cells become sensitized against intestinal antigens (3). The above observations have been confirmed and extended by other authors (4).

This work was supported by the US Energy Research and Development Agency and the Swiss National Foundation for Scientific Research.