A role for lactate in the differentiation of cultured sheep thyroid cells

A primary culture system for sheep thyroid cells was found to produce high levels of lactate. In the absence of medium changes the lactate began to disappear from the medium when the available glucose supply was exhausted. Follicular development and iodine trapping were maintained in the culture system only if medium changes were avoided. Investigations have shown that the extent of morphological differentiation is dependent on the length of time the cells are deprived of glucose and are metabolising lactate. Functional differentiation, shown by the ability to trap iodine, is also maintained when cells are forced to use lactate instead of glucose. A role for lactate in the differentiation of sheep thyroid cells is suggested.