title: Effects of parathyroid hormone on the osteoclastic pool, bone resorption and formation in rat alveolar bone.
abstract: The osteoclast number and its relation to parathyroid hormone have been studied in rat alveolar bone by quantitative histology and fluorescent labeling. The osteoclast number decreases 60 h after parathyroidectomy and remains constant for the next 132 h. Parathyroid hormone administration to parathyroidectomized animals 96 h after the operation induces an increase in osteoclast number within 12 h to somewhat above those of control animals. The elevated osteoclast counts remain constant for 60 h then rapidly fall over the next 24 h to the level seen in untreated parathyroidectomized animals. As determined by fluorescent labeling, normal alveolar bone resorption and formation were disturbed by parathyroidectomy, such that significant bone formation occurred for only 6 days after surgery, after which a quiescent state followed.
mesh_terms: D000539:Alveolar Process / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development; D000818:Animals; D001862:Bone Resorption / Q000187:drug effects*; D002118:Calcium / Q000097:blood; D005260:Female; D010010:Osteoclasts / Q000187:drug effects*; D010281:Parathyroid Hormone / Q000494:pharmacology*; D010758:Phosphorus / Q000097:blood; D051381:Rats
chemical_list: D010281:Parathyroid Hormone; D010758:Phosphorus; D002118:Calcium