CENTRAL PRESSOR EFFECT OF PARATHYROID HORMONE-RELATED PROTEIN IN CONSCIOUS RATS

Although the parathyroid hormone-related protein gene is widely expres sed in the central nervous system, the role of this protein in blood p ressure is unknown. This article examines whether parathyroid hormone- related protein is involved in the central regulation of blood pressur e. An intraventricularly injected solution of parathyroid hormone-rela ted protein elicited a dose-dependent increase of mean arterial pressu re accompanied by a decrease of heart rate in conscious Sprague-Dawley rats. An anti-parathyroid hormone-related protein monoclonal antibody , given in an intraventricularly injected solution, blocked the presse r effect of parathyroid hormone-related protein. Furthermore, this pre sser effect of parathyroid hormone-related protein was also abolished after pretreatment by intravenous administration of either hexamethoni um bromide or doxazosin mesylate. These results suggest that central p arathyroid hormone-related protein is implicated in the regulation of blood pressure, and that this effect may be mediated through sympathet ic activation. (C) 1998 Elsevier Science B.V.