Calcitonin is not given in which disease ?
Paget's disease
Thyrotoxicosis
Hyperparathyroidism
Hypervitaminosis D
Ans. is 'b' i.e., Thyrotoxicosis Calcitonin Calcitonin is a polypeptide hormone is produced by parafollicular 'C' cell of thyroid (major source). Parathyroids, thymus and cells of medullary carcinoma of thyroid also contain calcitonin. Synthesis and secretion of calcitonin is regualted by plasma Ca"- concentration itself - rise in plasma Ca' increases, while fall in plasma Ca" decreases calcitonin release. Actions It inhibits bone resorption by direct action on osteoblasts. Calcitonin inhibits proximal tubular calciun and phosphate reabsorption by direct action on kidney. Uses Hypercalcemic states Hyperparathyroidism, hypervitaminosis D, osteolytic bony metastasis and hypercalcemia of malignancy. Postmenopausal osteoporosis. Paget's disease.