DIASPIRIN CROSS-LINKED HEMOGLOBIN (DCLHB(TM)) - CONTROL OF PRESSOR EFFECT WITH ANTIHYPERTENSIVE AGENTS

Diaspirin crosslinked hemoglobin (DCLHbTM) administration elevates mea n arterial pressure (MAP). The purpose of this study was to determine whether commonly used antihypertensive agents could control this press er effect in rats. Awake rats were injected intravenously (iv) with 28 0 mg/kg of DCLHb. Fifteen minutes later when MAP was 25-30% above base line and heart rate (HR) was reciprocally decreased, prazosin (2 mg/kg ;an alpha adrenergic blocker), nitroglycerine (NTG; 10-150 meg/min; a nitrovasodilator), nicardipine (0.204-0.08 mg/hr; a calcium channel bl ocker) or labetalol (5 mg/kg; an alpha/beta adrenergic blocker) was ad ministered iv. All four classes of antihypertensive agents promptly re stored MAP to baseline. Coincident with the return of MAP to baseline, HR was restored to baseline in prazosin and NTG treated animals, howe ver, bradycardia persisted in those animals treated with nicardipine a nd labetalol, most likely due to the negative chronotropic properties of these agents. We conclude that the presser effect of DCLHb can be r eadily controlled with at least four different classes of commonly use d antihypertensive agents.