Parathyroid hormone (PTH)/PTH-related peptide type 1 receptor (PPR) signaling in osteocytes regulates anabolic and catabolic skeletal responses to PTH.

Parathyroid hormone (PTH) is the only Food and Drug Administration-approved anabolic agent to treat osteoporosis; however, the cellular targets of PTH action in bone remain controversial. PTH modulates bone turnover by binding to the PTH/PTH-related peptide (PTHrP) type 1 receptor (PPR), a G-protein-coupled receptor highly expressed in bone and kidneys. Osteocytes, the most abundant cells in adult bone, also express PPR.