Abstract 266: Renovascular Remodeling in Hypertensive Dahl-SS Rats: Role of MMP Inhibitor as a Hypertension Ameliorating Agent
High salt diet has long been associated with chronic hypertension. The development of renal injury in Dahl salt-sensitive (SS) hypertensive rats is characterized by structural and functional changes involving vascular remodeling. Increased activity of matrix metalloproteinases (MMPs) leading to alteration in the extracellular matrix (ECM) is the main mechanism contributing to increased peripheral vascular resistance. In this study, we hypothesized that inhibition of MMPs will modulate ECM remodeling by decreasing MMP activity and thus reduce mean arterial blood pressure.
METHODS: We used Dahl-salt sensitive (Dahl-SS) and
Lewis rats fed on high salt diet. The groups were 1) Dahl-SS, 2) Dahl-SS+GM6001 (non-specific MMP inhibitor), 3) Lewis, and 4) Lewis+GM6001. GM6001 was given at 0.5mg/mL by intra-peritoneal injection on alternate days for 3 weeks. Blood pressure, laser doppler flowmetry for renal cortical blood flow and barium angiography for renal vascular density were measured.
Results: Mean arterial blood pressure was 172.10 ± 0.57 mm Hg in hypertensive Dahl-SS rats compared to 136.12 ± 1.22 mm Hg in Dahl-SS+GM6001 rats. The mean arterial pressures in lewis and lewis+GM6001 groups were 97.08 ± 0.56 and 87.63 ± 2.93 mm Hg respectively. Laser doppler flowmetry showed reduced renal cortical blood flow (1333.33 flux units) in Dahl-SS rats compared to Dahl-SS rats treated with GM6001 (1605 flux units). Lewis rats showed similar renal cortical flow with (1488.33 flux units) or without GM6001 (1425 flux units). Barium angiography demonstrated increased renal vascular density with patent branches in the renal cortex of animals treated with MMP inhibitor, GM6001.
Conclusion: Our results suggest that in hypertensive Dahl-SS rats, inhibition of MMP attenuates high blood pressure, maintains patency of renal cortical vessels thus improving cortical blood flow.
- © 2012 by American Heart Association, Inc.