[Polymorphism of the human thyroid colloid as a physico-chemical and biological phenomenon]

The histological material from 83 thyroid glands obtained from male and female human subjects during the medico-legal examination, was studied at the light microscopic level using the general and histochemical staining methods. The phenomenon of age-related increase of follicular colloid density was investigated and various forms of this effect are classified. Possible physicochemical factors of colloid modification are examined. The latter include: colloid "aging", follicular cell desquamation followed by cell death, thyroglobulin desialization, and accumulation of excessive amounts of DNA and RNA in colloid. Biological significance of the excessive colloid accumulation in the follicles with its subsequent increase in density is regarded in the neutralization and isolation of iodine and tyrosine, which are considered as xenobiotics.