The response of 0steoblasts to parathyroid hormone (PTH 1–34) in vitro

Abstract Morphological study of osteoblasts of the endocranial aspect of the rat calvarium showed that they responded to the 1–34 fragment of parathyroid hormone in exactly the same way as to parathyroid extract : thus, the osteoblasts become elongated and aligned parallel to one another and to the collagen in the most superficial layer of the bone matrix. Fluctuations in PTH levels may conceivably relate to the lamellar texture of mature bone.