Calcitonin Activity in Ultimobranchial Neoplasms from Bulls

Abstract

Abstract. Ultimobranchial neoplasms from 5 bulls that were extracted and assayed individually contained approximately 68% as much calcitonin activity (452 * 68 MRC mU/g) as thyroid glands from control bulls (663 f 165 MRC mU/g). These results were consistent with the ultrastructural finding that thyroid neoplasms in old bulls were composed of primitive ultimobranchial cells which contained few mature secretory granules The ultimobranchial body is derived in higher vertebrates from the terminal branchial pouch in close proximity to other endocrine glands involved in the homeostatic regulation of mineral metabolism. Ultimobranchial tissue varies in postnatal location from within the pericardial transverse septum in fish, near the parathyroid glands in birds, to incorporation within the thyroid tissue in higher mammals. In cattle the ultimobranchial body becomes incorporated in the vasculo-stromal hilus of the thyroid with an ingrowth of cell cords along connective tissue stroma of the gland [19].

Immunohistochemical Study of the Ultimobranchial Remnants in the Camel

“…In higher mammalian subclasses, however, although both organs merged together to form thyroid gland but remnants of the ultimobranchial body have been observed in many species postnatally including human. In cattle, for instance, the ultimobranchial body and the pathological conditions that might developed from it have been described early in several publications (Krook, 1969;Young et al, 1971;Ljungberg and Nilsson, 1985;Harmon and Kelley, 2001). The ultimobranchial remnants were also thoroughly investigated in other domestic mammals like horse (Ueki et al, 2004), dog (Zarrin, 1977), sheep (Jordan et al, 1973), goat (Roy et al, 1978; Buffalo (Sayed et al, 2004); donkey (Sayed et al, 2004) and cat (Titlbach et al, 1987).…”