Vasopressin receptor antagonists are a new class of drugs that address the problems of fluid retention, hyponatremia, and renal dysfunction in heart failure. Elevated vasopressin levels in heart failure cause myocardial fibrosis, hypertrophy and vasoconstriction by activating the V1a receptors, as well as water retention and hyponatremia by activating V2 receptors. Antagonism of V1a receptors a...

BACKGROUND Low lymphocyte count has been shown to be an independent prognostic marker in heart failure (HF) in the outpatient setting. Limited data exist regarding whether relative lymphocyte count correlates with postdischarge outcomes in patients hospitalized for HF. METHODS AND RESULTS We performed a post hoc analysis of the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study...

The role of endogenous vasopressin in cardiovascular homeostasis was examined using vasopressin-deficient rats (Brattleboro) (n = 194) and their parent strain, Long-Evans rats (n = 181). Mean arterial pressure (blood pressure) and heart rate were measured every 4 seconds with or without infusion of drug solution for 21 hours, and mean values and their standard deviations (lability) were calcula...

Cardiovascular responses to step-changes of carotid sinus pressure were evaluated at normal and elevated levels of plasma arginine vasopressin in anesthetized neurohypophysectomized dogs (n = 12). Arginine vasopressin influenced autonomic function in two ways: first, maximum carotid reflex gain increased; second, cardiac output was decreased. The enhancement of reflex strength was observed only...

Urine concentration is regulated by vasopressin. Congenital nephrogenic diabetes insipidus (NDI) is caused by vasopressin type 2 receptor (V2R) mutations. We studied whether metformin could improve urine concentration in rodent models of congenital NDI by stimulating AMPK. To block the V2R in rats, tolvaptan (10 mg/kg/d) was given by oral gavage with or without metformin (800 mg/ kg/d). Control...

AIM This study investigated the relationship between the initial diuretic response to tolvaptan and clinical predictors for tolvaptan responders in patients with acute decompensated heart failure (ADHF). METHODS AND RESULTS Patients (153) with ADHF (clinical scenario 2 or 3 with signs of fluid retention) who were administered tolvaptan were enrolled. Tolvaptan (15 or 7.5 mg) was administered ...

b i t m t p h g a ASOPRESSIN (VP) WAS DISCOVERED in 1895 from the extract of the posterior pituitary and named for the arly observation of its vasoconstrictive properties.1 The eptide is present in various species, both invertebrate and ertebrate, with only minor variations in amino acid seuence. Human VP contains the amino acid arginine, hence he name arginine vasopressin. It is alternatively ...