[Immunocytological studies of C cells with anti-calcitonin or antisomatostatin immunoserums in rats treated with vitamin D, thyroxine or benzyl-thiouracil].

In rats treated with vitamin D3, thyroxin or BTU alone or with associations of vitamin D3 + BTU or vitamin D + thyroxin, immunocytochemical studies with an anti-human calcitonin serum show a stimulating effect of vitamin D and of thyroxin and an inhibiting effect of BTU on the C cells of the thyroïd. These results are in agreement with the existence of functional relations between follicular and C cells. A few calcitonin-containing cells are immunoreactive to an anti-somatostatin serum. All the C cells contain both calcitonin and somatostatin when they are grouped in a single big interfollicular cluster.