Histological Structure and Calcitonin Secretion of the Japanese Newt Ultimobranchial Body in the Urodeles Amphibians

Abstract

Summary: Morphological investigation of the ultimobranchial body (Ult) of the Urodeles amphibian red-bellied Japanese newt (Cynops pyrrhogaster) revealed that it had only one Ult located on the left behind the arch of the aorta between the paired thyroid glands and parathyroid glands to the left of the trachia. The Ult had no capsule and consisted of a group of follicles. The follicles were made up of the cubic epithetical cells. The average size of the Ult was 350 μm (canio-caudal length) × 210 μm (ventro-dorsal length) × 420 μm (left-right length). The follicular cells of the Ult were differentiated by lead-hematoxylin staining. They also reacted positively in the immunohistochemical method using antiserum against pig calcitonin. This was a clear indication that these cells were related to the secretion of calcitonin.