Aldosterone, Sodium Deficiency, and Insulin Resistance
The Randle Cycle
Free Fatty Acids Suppress Cellular Respiration
Aldosterone as an endogenous cardiovascular toxin
Sodium Deficiency and Stress
Low Sodium Diet: High FFA, Insulin Resistance, Atherosclerosis
Oral Contraceptives, Estrogen, and Clotting
Postepy Hig Med Dosw (Online). 2010 Oct 18;64:471-81.
[Prothrombotic aldosterone action--a new side of the hormone].
[Article in Polish]
Gromotowicz A, Osmólska U, Mantur M, Szoka P, Zakrzeska A, Szemraj J, Chabielska E.
Recent studies have focused on a new wave of interest in aldosterone due mainly to its growing profile as a local messenger in pathology of the cardiovascular system, rather than its hormonal action. In the last few years strong evidence for a correlation between raised aldosterone level and haemostasis disturbances leading to increased risk of cardiovascular events has been provided. It has been demonstrated that aldosterone contributes to endothelial dysfunction, fibrinolytic disorders and oxidative stress augmentation. It was also shown that chronic aldosterone treatment results in enhanced experimental arterial thrombosis. Our study in a venous model of thrombosis in normotensive rats confirmed that even a short-lasting increase in aldosterone level intensified thrombus formation. One-hour aldosterone infusion shortened bleeding time; increased platelet adhesion to collagen; reduced tissue factor, thrombin activatable fibrinolysis inhibitor, and plasminogen activator inhibitor; and increased plasminogen activator plasma level. A fall in plasma nitric oxide metabolite concentration with a decrease in aortic nitric oxide synthase mRNA level was also observed. Moreover, aldosterone increased hydrogen peroxide and malonyl dialdehyde plasma concentration and augmented NADPH oxidase and superoxide dismutase aortic expression. Therefore, the mechanism of aldosterone prothrombotic action is multiple and involves primary haemostasis activation, procoagulative and antifibrinolytic action, NO bioavailability impairment and oxidative stress augmentation. The effects of aldosterone were not fully abolished by mineralocorticoid receptor blockade, suggesting the involvement of alternative mechanisms in the prothrombotic aldosterone action.
J Renin Angiotensin Aldosterone Syst. 2011 Dec;12(4):430-9. Epub 2011 Mar 18.
Study of the mechanisms of aldosterone prothrombotic effect in rats.
Gromotowicz A, Szemraj J, Stankiewicz A, Zakrzeska A, Mantur M, Jaroszewicz E, Rogowski F, Chabielska E.
We investigated the role of primary haemostasis, fibrinolysis, nitric oxide (NO) and oxidative stress as well as mineralocorticoid receptors (MR) in acute aldosterone prothrombotic action.
MATERIALS AND METHODS:
Venous thrombosis was induced by stasis in Wistar rats. Aldosterone (ALDO; 10, 30, 100 µg/kg/h) was infused for 1 h. Eplerenone (EPL; 100 mg/kg, p.o.), a selective MR antagonist, was administered before ALDO infusion. Bleeding time (BT) and platelet adhesion to collagen were evaluated. The expression of nitric oxide synthase (NOS), NADPH oxidase, superoxide dismutase (SOD) and plasminogen activator inhibitor (PAI-1) was measured. NO, malonyl dialdehyde (MDA) and hydrogen peroxide (H(2)O(2)) plasma levels were assayed.
Significant enhancement of venous thrombosis was observed after ALDO infusion. ALDO shortened BT and increased platelet adhesion. Marked increases were observed in PAI-1, NADPH oxidase and SOD mRNA levels. MDA and H(2)O(2) levels were augmented in ALDO-treated groups, and NOS expression and NO level were decreased. EPL reduced ALDO effects on thrombus formation, primary haemostasis, PAI-1 expression and MDA level.
Short-term ALDO infusion enhances experimental venous thrombosis in the mechanism involving primary haemostasis, fibrinolysis, NO and oxidative stress-dependent pathways. The MR antagonist only partially diminished the ALDO effects, suggesting the involvement of additional mechanisms.