Ultimobranchial and parathyroid glands of the pigeon Columba livia in response to 1,25(OH) 2 D 3 administration

Columba livia were given daily intraperitoneal injections of 100 pmol of 1,25(OH) 2 D 3 /100 g body wt. for 15 days. Ultimobranchial and parathyroid glands were fixed on 1st, 3rd, 5th, 10th and 15th day of the experiment. Following 1,25(OH) 2 D 3 treatment, the plasma calcium levels of pigeon remain unchanged on day 1. The levels increase significantly after day 3 which progresses up to day 10. The plasma calcium level becomes normal at day 15. The plasma inorganic phosphate levels of Columba livia injected with 1,25(OH) 2 D 3 remain unaffected up to day 3. The levels exhibit a progressive increase from day 5 to day 10. The levels become normophosphatemic at day 15. Up to day 3 following 1,25(OH) 2 D 3 treatment, there is no change in the ultimobranchial gland of Columba livia . The gland exhibits an increased activity after 5 days 1,25(OH) 2 D 3 treatment which is evident by the increased nuclear volume and weak staining response of the cytoplasm of ultimobranchial cells. After day 10, the nuclear volume depicts a further increase and a few completely exhausted cells are discerned. Following 15‐day 1,25(OH) 2 D 3 treatment the nuclear volume records an increase and degenerating cells have been observed at certain places. The parathyroid glands of 1,25(OH) 2 D 3 ‐treated Columba livia remain unaffected up to day 5. After day 10 and day 15, there is a progressive decrease in the nuclear volume of parathyroidal cells and reduced chromaticity of nuclei has been noticed. Moreover, after 15 days few degenerating cells are observed. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.