Key Points
- To investigate whether angiotensin II is generated locally within peripheral vascular tissues and to determine its functional role in the pathogenesis of renal hypertension.
- Measured the dose of angiotensin II antiserum required to block the pressor response to exogenous angiotensin II in rats with suppressed renin-angiotensin systems (induced by a high-salt diet or bilateral nephrectomy), with and without renin infusion.
- Assessed antiserum blocking requirements and sodium balance status in a rat model of renal hypertension created by unilateral renal artery constriction with contralateral nephrectomy.
- Suppression of the endogenous renin-angiotensin system significantly increased the dose of antiserum required to neutralize exogenous angiotensin II pressor responses, whereas renin infusion profoundly reduced this requirement.
- Hypertensive rats subjected to renal artery constriction and contralateral nephrectomy exhibited low antiserum blocking requirements despite maintaining a positive sodium balance.
- Locally generated angiotensin II occupies vascular receptors directly at the tissue level, providing a mechanism for sustained renal hypertension even in the presence of circulating neutralizing antibodies.
Structured PICO
Does local generation of angiotensin II at the peripheral vascular level play a role in renal hypertension in rat models?
PPopulationRats with suppressed renin-angiotensin system (via high salt diet or bilateral nephrectomy) and rats with renal hypertension (via renal artery constriction with contralateral nephrectomy)
IInterventionAngiotensin II antiserum, exogenous angiotensin II, and renin infusion
OOutcomeBlocking requirement of angiotensin II antiserum to block the pressor action of exogenous angiotensin IIsurrogate
The study suggests that local generation of angiotensin at the blood vessel level may contribute to renal hypertension, explaining why hypertension develops even in animals immunized against angiotensin.