La goitrigenèse expérimentale.

Various modern aspects of experimental goitrogenesis are reviewed and discussed. Regulation of follicular cell proliferation clearly involves several stimulatory but also inhibitory mechanisms. Furthermore, different stimuli are probably involved. Growth of the vascular and connective interstitial tissue probably involves paracrine factors and that of the follicles maybe autocrine factors; indeed, several growth factors are secreted by stimulated follicular cells. The formation of nodules is still poorly understood. They could derive from different cell populations or from cells being in different reactivity status with respect to the variations of the iodine fluxes in the gland. Finally, the relationship between iodine toxicity, nodularity and autoimmunity are discussed.