Functional Accessory Parathyroid Tissue in Ultimobranchial Bodies of Chickens

Abstract

Plasma calcium concentrations dropped precipitously in birds whose parathyroid glands, ultimobranchial bodies, or both had been removed 11 hr previously as compared with those of sham-operated controls. By 50 hr after surgery, plasma calcium concentrations returned to near control values in PT-X + UB-X birds but remained low in PT-X + UB-X birds. These data (together with histologic evidence of parathyroid tissue within ultimobranchial bodies), constitute direct evidence for the secretion of parathormone by the accessory parathyroid tissue in the ultimobranchial bodies.