Enhanced thrombotic responses are associated with striatin deficiency and aldosterone

Abstract

BACKGROUND: In addition to its role on blood pressure, aldosterone (ALDO) also affects the hemostatic system leading to increased experimental thrombosis. Striatin is an intermediate in the rapid, nongenomic actions of ALDO. Striatin heterozygote knockout (Strn+/-) mice have salt sensitivity of blood pressure and mildly chronically increased ALDO levels. In addition, in humans, striatin polymorphic gene variants are associated with increased salt sensitivity of blood pressure. Thus, we hypoth-esized that striatin deficiency would be associated with an increased prothrombotic response. METHODS AND RESULTS: Strn+/- mice and wild-type littermates were maintained on a liberal sodium diet (1.6%). We measured in vivo thrombus formation following laser-induced injury in cremaster arterioles using intravital microscopy. Mice were randomized to intravenous administration of ALDO or its vehicle. Acutely, ALDO increased thrombotic responses in wild-type mice (P<0.01) versus controls within minutes as determined by increased platelet accumulation and fibrin deposition at the site of laser injury. We then compared thrombus formation without ALDO administration in Strn+/- and wild-type mice. Strn+/- mice showed highly significant increases in laser-induced thrombosis (P<0.001), as shown by increased platelet accumulation and fibrin deposition. Interestingly, the response in the Strn+/- mice basally was far greater than the wild-type mice with ALDO ad-ministration, and ALDO administration produced no additional effect on thrombus responses in Strn+/- mice. CONCLUSIONS: These results demonstrate a novel protective role of striatin in experimental thrombosis. Such a protective effect may be reduced in human striatin risk allele carriers, given the similar salt sensitivity of blood pressure in these individuals and Strn+/- mice.