Cytokine-Induced Expression of Parathyroid Hormone-Related Peptide in Cultured Human Vascular Endothelial Cells

Abstract Parathyroid hormone-related peptide (PTHrP) is a potent vasodilatory peptide whose expression has been demonstrated in various tissues. The present study was undertaken to examine the regulation of PTHrP expression in cultured endothelial cells derived from human umbilical vein. Immunoradiometric assay revealed that the amount of PTHrP in the conditioned medium was increased by both tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) in both a time- and a dose-dependent manner. The induction of PTHrP mRNA was also observed, with a peak after 2 hours of incubation with both TNF-α and IL-1β. Angiotensin II, endothelin-1, and arginine vasopressin had no affect on PTHrP production. Our results suggest that PTHrP produced in vascular endothelial cells in response to cytokines may modulate vascular function as a local factor.