Malignant hypertension - the role of the paracrine renin-angiotensin system.

ABSTRACT

Malignant hypertension remains one of the life-threatening complications of blood pressure elevation. It is a clinico-pathological syndrome of severe blood pressure elevation combined with malignant vascular injury. This is a characteristic form of vascular damage, with two elements fibrinoid necrosis and endarteritis proliferans. Although the morphology of these has been well described, the molecular events are not fully understood. This review summarizes the evidence from transgenic animals for a role for the activation of a local paracrine renin-angiotensin system in the pathogenesis of malignant vascular injury. These animal models provide pathological, pharmacological, and genetic evidence supporting the hypothesis that intra-renal generation of angiotensin 2 and exposure of the microcirculation to elevated blood pressure co-operate in causing tissue damage in malignant hypertension.