#694 Effects of nonsteroidal mineralocorticoid receptor antagonists on kidney of cirrhotic rats

Abstract

Abstract Background and Aims Aldosterone binds to renal mineralocorticoid receptors (MRs) to regulate fluid and electrolytes homeostasis. In addition, aldosterone can be deleterious as a driver of inflammation and tissue fibrosis in several organs. Thus, blockade of aldosterone represents an important option to mitigate the target-organ damage. Mineralocorticoid receptor antagonists (MRAs) have been widely used as diuretic drugs for the management of hypertension, cirrhosis, and heart failure. However, the use of MRAs is limited by adverse events such as hyperkalemia. More recently, novel nonsteroidal selective MRAs with improved safety profiles have been developed. This nonsteroidal MRA (finerenone) has higher selectivity and stronger affinity for the MR, leading to lower risk of hyperkalemia. Recent evidences showed that finerenone reduces albuminuria, risk of CKD progression, and cardiovascular events in patients with chronic kidney disease and type 2 diabetes with a low incidence of hyperkalemia related treatment discontinuation. The pathophysiology of cirrhosis is very similar to that of cardiac failure. Decompensated cirrhosis is frequently treated with the MRAs. In addition to fluid management, MRAs showed hepatoprotective actions via reducing oxidative stress and inflammatory responses in CCl4-induced and common bile duct ligation (CBDL)-induced liver injury models. The potential beneficial effects of nonsteroidal MRA on cirrhosis had never been studied. This study aims to explore the renal protective role of nonsteroidal selective MRA and associated mechanisms in common bile duct ligation-related liver injury in rat model. Method CBDL was used to create liver injury in the Male Sprague-Dawley Drats. Finerenone (10 mg/kg/day) or vehicle was administered since the 1st day after CBDL. The effects of nonsteroidal selective MRA on kidneys were surveyed in two paralleled series on the 7th day (inflammation) and the 28th day (cirrhosis), respectively. The following parameters were evaluated: (a) hemodynamic parameters; (b) serum potassium, liver and renal function; (c) in-situ kidney perfusion; (d) western analyses of renal cortex and medulla. Results Compared with the vehicle-treated group, there was significantly lower renal vascular responsiveness to ET-1 in CBDL rats receiving 28 days of MRA (p<0.05) (Fig. 1B), but not in those receiving 7 days of MRA (Fig. 1A). MRA treatment led to no significant change in mean arterial pressure, portal pressure, serum potassium, liver, and renal function in CBDL rats (Table 1). The expressions of vasoactive mediators, such as iNOS, eNOS, ETA, and ETB in both renal cortex and medulla showed no significant change in CBDL rats following 28 days of MRA treatment (Fig. 2). Conclusion MRA treatment led to no significant effects on hemodynamics, liver, and renal function, but lower renal vascular responsiveness to ET-1 in CBDL rats receiving 28 days of MRA. The exact mechanisms remained to be further studied.