Cardiorenal syndrome and vitamin D receptor activation in chronic kidney disease

Vitamin D: A Bridge between Kidney and Heart

Chronic kidney disease (CKD) and cardiovascular disease (CVD) are highly prevalent conditions, each significantly contributing to the global burden of morbidity and mortality. CVD and CKD share a great number of common risk factors, such as hypertension, diabetes, obesity, and smoking, among others. Their relationship extends beyond these factors, encompassing intricate interplay between the two systems. Within this complex network of pathophysiological processes, vitamin D has emerged as a potential linchpin, exerting influence over diverse physiological pathways implicated in both CKD and CVD. In recent years, scientific exploration has unveiled a close connection between these two prevalent conditions and vitamin D, a crucial hormone traditionally recognized for its role in bone health. This article aims to provide an extensive review of vitamin D's multifaceted and expanding actions concerning its involvement in CKD and CVD.

Cardioprotective effect of abscisic acid in a rat model of type 3 cardio-renal syndrome: Role of NOX-4, P-53, and HSP-70

Cardiorenal syndrome (CRS) is a complex heart and kidney pathophysiologic disorder that leads to a bidirectional interrelationship between them. Abscisic acid (ABA) is a phytohormone that is present in plants, and is known to regulate fundamental physiological functions. This study aimed to explore the efficacy of ABA in surgically induced-CRS type 3 rats. Rats were randomly and equally divided into four groups. Rats in Group 1 received saline (Sham group), Group 2 included control induced-CRS rats, Group 3 rats (CRS+ABA) included CRS rats treated with ABA and Group 4 (CRS + ABA + Verapamil + propofol) were CRS rats treated with Verapamil, propofol and ABA. The rats were treated with the drugs daily for four weeks. At the end of the study, relative heart weight corrected QT interval (QTc), mean blood pressure (MBP), kidney functions, oxidative stress, NADPH oxidase 4 (NOX4), protein 53 (P53), and heat shock proteins-70 (HSP-70) expression was assessed and recorded. ABA led to a significant shortening of the ventricular action potential duration indicated by QTc. Furthermore, it significantly lowered heart weight, MBP, serum creatinine, NOX-4, and P-53 expression and augmented HSP-70 expression. In contrast, adding calcium channel blockers (CCBs) to ABA mitigated this effect. The results suggested that ABA has a potential protective role in CRS-induced cardiac hypertrophy and arrhythmia that could be mediated through inhibition of P-53, NOX-4, and an increase in HSP-70 expression.

Pathophysiology of Cardiorenal Syndrome and Use of Diuretics and Ultrafiltration as Volume Control

Acute deterioration in kidney function in the setting of decompensated heart failure, known as cardiorenal syndrome, results from venous congestion. Although diuretics or ultrafiltration are effective measures in decreasing venous congestion and improving symptoms in patients with cardiorenal syndrome, the impact of decongestive therapy on kidney function or mortality remains uncertain. A precise assessment of venous congestion is required to assess the adequacy of patients' response to decongestive therapy and to guide therapeutic decision making.

Acute or chronic dysfunction of the heart or kidneys can cause dysfunction of other organs. This interaction between the heart and kidneys is characterized as cardiorenal syndrome (CRS). Recently, a preponderance of data indicated that venous congestion plays an important role in the combination of renal and cardiac diseases. This review aims to focus on the pathophysiology of venous congestion that leads to renal impairment in heart failure and the use of diuretics or ultrafiltration as decongestive therapy in CRS. We found that although clinical studies have confirmed that decongestive therapy has a definite role in decreasing volume overload and the consequent symptom improvement in patients with CRS, the impact of diuretics or ultrafiltration on the improvement of kidney function or mortality remains uncertain. A precise assessment of volume status is required to determine the adequacy of decongestion. Objective measures of renal venous congestion may be a future metric to assess the adequacy of the diuretic response in patients and guide therapeutic decision making.