Thyrotropin effects on vesicle transfer and thyroid follicle morphogenesis: a stereological study in the rat

Abstract

Incubation in a culture medium with and without TSH of 16 day-old foetal thyroid glands induces hypertrophy of the Golgi apparatus which may be correlated with a considerable increase in the number of secretory vesicles. A stereological study performed during the first 6 hr of incubation showed that: vesicle secretion was biphasic; vesicle secretion was heterogeneous with two different populations of vesicles; When TSH (20 mU and 80 mU) was added to the medium, the volume density of the follicular lumina increased; at least during the first 6 hr TSH seemed to be necessary to the formation of follicular lumina.

Thyrocytes, but not C cells, actively undergo growth and folliculogenesis at the periphery of thyroid tissue fragments in three-dimensional collagen gel culture

“…These results together suggest that thyroid folliculogenesis itself may be TSH independent, at least when using particular methods or species. However, we cannot rule out the possibility that the lack of responsiveness of thyrocytes to TSH may relate to our specific culture system, possible factors contained within the serum or the species used (Ericson and Nilsson 1996;Remy et al 1983;Roger et al 1997;Spooner and Hilfer 1971). Further studies are required to answer these questions.…”