Longterm Cultures of Sheep Thyroid Cells

Stimulation by thyrotropin and cyclic AMP of the proliferation of quiescent canine thyroid cells cultured in a defined medium containing insulin

“…In a few culture systems, thyrotrophin (TSH) stimulates DNA synthesis and proliferation [14-161, but not in several others [13,17,18]. In terms of mechanisms, dog thyroid cells in primary culture in monolayer remain a unique model as, in this sytem, the growth-promoting action of TSH has been shown to be reproduced by increasing intracellular CAMP levels [la].…”

An investigation of the optimum culture conditions for a differentiated culture of sheep thyroid cells

“…If large cell numbers were required to initiate a differentiated system, studies of the human thyroid by biopsy would be impossible. The results presented here indicate that an initial cell number of about 1 x 106 extends the culture life span and induces an improvement in the morpho¬ logical and functional characteristics of the culture system described by O'Connor et al (1980) but that below that number differentiation is difficult to detect.…”

“…Since previous investigations of this culture system demonstrated that the extension of differentiated cell life was dependent on the culture conditions (O'Connor et al 1980) this study was undertaken with a view to optimising the media for differen¬ tiated sheep thyroid cultures in an attempt to extend cell life by using media with extra energy substrates.…”

“…These cultures were useful for short-term studies but loss of differentiation prohibited long-term evaluation of the effect of hormones, anti-thyroidal drugs and radiation on the thyroid in vitro. O'Connor et al (1980) demonstrated that folli¬ cular structures and iodide trapping could be pre¬ served if no medium changes were made during the culture period. The follicular morphology im¬ proved for up to 20 days after which the cells rapidly died due to lack of nutrients (Mothersill et al 1980).…”

Establishment and Characterization of a Malignant Epithelioid Hemangioendothelioma from Mouse Tnyroid Tumor.

“…In contrast, the growth of human, sheep and porcine thyroid cells was inhibited by TSH in in vitro culture [6][7][8]. Several groups have now succeeded in confirming the in vitro growthstimulatory effect of TSH, even for human follicular cells, provided that stimulatory DNA synthesis was induced with an additional growth factor, such as insulin-like growth factor (IGF)-I [9,10].…”