D.R. Chadwick, B.J. Harrison, P. Chan*, L. Chong and P. Peachell [ Departments of Endocrine Surgery and *Vascular Surgery, Northern General Hospital and Section of Molecular Pharmacology and Pharmacogenetics, University of Sheffield Royal Hallamshire Hospital, Sheffield, UK]
Vasoactive and Proliferative Effects of Parathyroid Hormone and Parathyroid Hormone-Related Peptide on Human Vascular Smooth Muscle
Br. Jour. of Sur. Volume 87, No.11, November 2000, Pgs- 1529-1533
Hyperparathyroidism is associated with an increased incidence of hypertension and cardiovascular disease. This probably results from desensitization of the normally inhibitory effects of parathyroid hormone-related peptide [PTHrP] on vascular smooth muscle cells [VSMCs] by previous exposure to parathyroid hormone [PTH].
Isometric tension in vitro was measured in segments of vessels obtained at neck surgery from six normotensive patients with hyperparathyroidism and 12 eucalcaemic controls. Vessels were precontracted with noradrenaline to allow the vasodilatory effects of PTH and PTHrP.
Human VSMCs were cultured in 0.5%, 5% and 15% serum with or without PTH, and proliferation was assessed by cell counts after 14 days.
There was no difference in the results obtained between controls and hyperparathyroidism groups.
This data implies that homologous desensitization to PTHrP is not implicated in the pathogenesis of vascular disease in patients with hyperparathyroidism.