HOME
Search 2003 Abstracts

Return to Table of Contents

382

ELEVATED PLASMA COAGULATION FXIIA LEVELS AND HIGH ‘NEW PRESSOR PROTEIN’ (NPP) ACTIVITY IN PEDIATRIC HEMODIALYSIS PATIENTS WITH UNEXPLAINED RENOPRIVAL HYPERTENSION

PC Papageorgiou, RJ Pearl, M Goldman, AA Amfilochiadis, R Rojkjaer, DF Geary, DH Osmond

Toronto, Ontario

Unexplained hypertension was observed in three anephric children on hemodialysis. We therefore investigated possible involvement by the novel extra-renal enzyme ‘New Pressor Protein’ (NPP) which is structurally related to coagulation b-FXIIa (J Hypertens 16:311-320, 1998; Can J Cardiol 18(10):1077-1086; 1093-1103, 2002) and produces potent hypertensive cardiovascular and sympatho-adrenal effects. NPP activity (DSBP mmHg) from normal human plasma (NHP, 250µL i.v.) and from our patients’ plasmas (250µL i.v.) were measured in male Wistar bioassay rats (~300g), anesthetized with Inactin (100 mg/kg i.p.) and given Pentolinium (19.2 mg/kg s.c.) and Captopril (2.5 mg/kg i.v.). The SBP increments (DmmHg) were recorded using a MacLab/8 PowerMac 7200 computerized system. Plasma FXIIa levels in NHP and patients’ plasmas were determined by immunoassay (Axis-Shield Diagnostics Ltd., Dundee, UK).

Pre-dialysis, patients AS and HI were hypertensive and their plasmas exhibited abnormally high NPP activity and plasma FXIIa levels. Post-dialysis, patients AS and HI reached their estimated dry body weight and their systemic pressures dropped in parallel with both NPP activity and plasma FXIIa levels. Patient JS remained hypertensive and hypervolemic, both pre- and post-dialysis, and NPP activity and plasma FXIIa levels dropped but still remained abnormally high. Our data suggest that high endogenous plasma NPP activity and FXIIa levels exist in these hemodialysis patients and change in relation to systemic BP and fluid volume status enough to suggest involvement in their hypertension.

DNC

Heart and Stroke Foundation of Ontario grants NA3478 and T4136

NEXT