Renin-angiotensin-aldosterone system blockade with enalapril or aldactone prevented severe blood pressure increases and corresponding renal damage in salt-supplemented hypertensive rats.
Does enalapril or aldactone prevent renal damage independently of blood pressure in salt-supplemented stroke-prone spontaneously hypertensive rats?
Renoprotection by RAAS blockade in salt-supplemented stroke-prone spontaneously hypertensive rats is blood pressure-dependent, highlighting the limitations of conventional tail-cuff BP measurements.
p-value: p=<0.05
Renin-angiotensin-aldosterone system blockade has been shown to protect against renal damage in salt-supplemented, stroke-prone spontaneously hypertensive rats (SHRsp). Based on intermittent tail-cuff blood pressure (BP) measurements, it has been claimed that such protection is BP-independent and mediated by a blockade of the direct tissue-damaging effects of angiotensin and/or aldosterone. BP radiotelemetry was performed for 8 weeks in approximately 10-week-old male SHRsp who received a standard diet and either tap water (n=10) or 1% NaCl to drink. Saline-drinking SHRsp were either left untreated (n=12), received enalapril (50 mg/L) in drinking fluid (n=9), or had subcutaneous implantation of time-release 200-mg pellets of aldactone (n=10). The average systolic BP (mean+/-SEM) during the final 3 weeks was significantly higher (P5 was only observed in SHRsp whose average systolic BP during the final 3 weeks exceeded 200 mm Hg, indicating a threshold relation with BP. These data show that protection by renin-angiotensin-aldosterone system blockade in this model is BP-dependent and mediated by preventing the severe increases in BP seen in untreated salt-supplemented SHRsp and further underscore the limitations of interpretations based on conventional tail-cuff BP measurements.
Griffin et al. (2003) studied Hypertension and renal damage (n=41). Enalapril or aldactone vs. Untreated saline-drinking or tap water-drinking was evaluated on Average systolic BP during the final 3 weeks (p=<0.05). Renin-angiotensin-aldosterone system blockade with enalapril or aldactone prevented severe blood pressure increases and corresponding renal damage in salt-supplemented hypertensive rats.