“…Lysosomal hydrolases of the thyroid gland represent a complex of different enzymes which play a maj or role in the intrathyroidal digestion of thyroglobulin decomposing its compound glycoprotein structure (Wollman, 1969;Van den Hove-Vandenbroucke, 1980). Optimal activity of thyroid intralysosomal proteases is shown at low pH values (Alpers et al, 1955;Poffenbarger et al, 1963;Jablonski and McQuillan, 1967;Ahn and Rosenberg, 1967;Smith et al, 1969;Peake et al,, 1970;Pisarev and Altschuler, 1973;Itikawa and Kawada, 1974). However, their pH maximum depends on the origin of thyroid lysosomes, i.e.…”