Protective Effects of Amlodipine Pretreatment on Contrast-Induced Acute Kidney Injury And Overall Survival In Hypertensive Patients

Navigating nephrotoxic waters: A comprehensive overview of contrast-induced acute kidney injury prevention

Contrast-induced acute kidney injury (CI-AKI) is the third leading cause of acute kidney injury deriving from the intravascular administration of contrast media in diagnostic and therapeutic procedures and leading to longer in-hospital stay and increased short and long-term mortality. Its pathophysiology, although not well-established, revolves around medullary hypoxia paired with the direct toxicity of the substance to the kidney. Critically ill patients, as well as those with pre-existing renal disease and cardiovascular comorbidities, are more susceptible to CI-AKI. Despite the continuous research in the field of CI-AKI prevention, clinical practice is based mostly on periprocedural hydration. In this review, all the investigated methods of prevention are presented, with an emphasis on the latest evidence regarding the potential of RenalGuard and contrast removal systems for CI-AKI prevention in high-risk individuals.

Amlodipine alleviates renal ischemia/reperfusion injury in rats through Nrf2/Sestrin2/PGC-1α/TFAM Pathway

BACKGROUND

Previously, observational studies showed that amlodipine can mitigate calcineurin inhibitor- and contrast-induced acute kidney injury (AKI). Herein, we aimed to measure the effect of amlodipine on renal ischemia/reperfusion (I/R) injury and find the underlying mechanisms.

MATERIALS AND METHODS

Bilateral renal I/R was induced by clamping the hilum of both kidneys for 30 min. The first dose of amlodipine 10 mg/kg was gavaged before anesthesia. The second dose of amlodipine was administered 24 h after the first dose. Forty-eight hours after I/R, rats were anesthetized, and their blood and tissue specimens were collected.

RESULTS

Amlodipine significantly decreased the elevated serum levels of creatinine and blood urea nitrogen (BUN) and mitigated tissue damage in hematoxylin & eosin (H&E) staining. Amlodipine strongly reduced the tissue levels of malondialdehyde (MDA), interleukin 1β (IL1β), and tumor necrosis factor α (TNF-α). Amlodipine enhanced antioxidant defense by upregulating nuclear factor erythroid 2-related factor 2 (Nrf2) and Sestrin2. Furthermore, amlodipine significantly improved mitochondrial biogenesis by promoting Sestrin2/peroxisome proliferator-activated receptor-gamma coactivator (PGC-1α)/mitochondrial transcription factor A (TFAM) pathway. It also enhanced autophagy and attenuated apoptosis, evidenced by increased LC3-II/LC3-I and bcl2/bax ratios after renal I/R.

CONCLUSION

These findings suggest that amlodipine protects against renal I/R through Nrf2/Sestrin2/PGC-1α/TFAM Pathway.

Blood Pressure Control Following Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers: Insights from a Triple-Blind, Randomized, Clinical Trial

Data on substituting one antihypertensive medication with the proper dose of another antihypertensive medication, in certain medical conditions, are scarce. Herein, we present the results of replacing angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) with the calcium channel blocker (CCB) amlodipine, with or without the alpha- and beta-blocker carvedilol, to control high blood pressure in patients with coronavirus disease 2019 (COVID-19). Iranian hypertensive patients with COVID-19 and a history of taking ACEI or ARB were randomized to "continue" and "change" groups. The continue group comprised patients who continued using their previous antihypertensive medication regimen as normal, whereas patients in the change group had their antihypertensive drugs changed to the CCB amlodipine, with or without the alpha- and beta-blocker carvedilol, based on their response to amlodipine. Patients' blood pressures were measured for 8 days following their recruitment. A total of 31 and 33 patients were randomly allocated to the ACEI/ARB continue and ACEI/ARB change groups, respectively. No significant deviations were seen in patients' systolic blood pressure by substituting an ACEI/ARB agent with the CCB amlodipine, with or without the alpha- and beta-blocker carvedilol. Moreover, the change group had a more balanced systolic blood pressure (ie, 110-130 mmHg) compared with the continue group (ie, 111.5-140.0 mmHg) throughout their hospitalization period. During their hospitalization, the blood pressure of the change group was well controlled with the proposed equivalent doses. Further investigations of the proposed equivalent doses in larger randomized clinical trials, populations other than Iranian COVID-19 patients, and extended duration are encouraged (clinical trial registration ID: IRCT20151113025025N3).

An in vivo and in vitro model on the protective effect of cilnidipine on contrast-induced nephropathy via regulation of apoptosis and CaMKⅡ/mPTP pathway

Contrast-induced nephropathy (CIN) is an acute kidney injury (AKI) observed after the administration of contrast media. Calcium channel blockers (CCBs) have been reported to exert a renal protective effect. This study aims to investigate the role of cilnidipine, a novel CCBs, on CIN by regulating the calcium/calmodulin-dependent protein kinase Ⅱ(CaMKⅡ)/mitochondrial permeability transition pore (mPTP) pathway. Here, iohexol, a representative contrast media, was used to establish CIN model. KN-93 (CaMKⅡ inhibitor) and atractyloside (mPTP opener) were administered in rats, and CaMKⅡ overexpression was used in Human proximal tubular epithelial cells. Markers of renal injury (serum creatinine, blood urea nitrogen, and urinary NAGL), hematoxylin-eosin stain, oxidative stress (ROS, superoxide dismutase [SOD], and malondialdehyde [MDA] levels), cell death (MTT and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling [TUNEL]), mitochondrial function (mPTP, mitochondrial membrane potential [MMP], and ATP) were assessed. Western blots were used to measure the expression levels of Bax/Bcl-2, caspase-3, CaMKⅡ/mPTP signaling pathways. Results showed that cilnidipine markedly improved kidney function, and alleviated tubular cell apoptosis, oxidative stress and mitochondrial damage induced by iohexol in vitro and in vivo. The underlying mechanism may be that cilnidipine relieved CaMKⅡ activation and mPTP opening induced by iohexol. All of these protective effects of cilnidipine were attenuated by CaMKⅡ overexpression and atractyloside (mPTP opener) pretreatment. Moreover, KN-93 (CaMKⅡ inhibitor) treatment showed a similar renal protective effect with cilnidipine, while the protective effect of cilnidipine on kidney in CIN rats was not further suppressed by KN-93 cotreatment. These in vitro and in vivo results point toward the fact that cilnidipine might be a novel therapeutic drug against contrast-induced nephrotoxicity in a CaMKⅡ-dependent manner.

Comparison of the Ameliorating Effects of Valsartan and Amlodipine on Vascular Endothelial Dysfunction and Oxidative Stress in Elderly Patients with Type H Hypertension

Objective

To explore whether long-term administration of valsartan or amlodipine can improve vascular endothelial function and reduce the production of reactive oxygen species in patients with H-type hypertension, so as to provide a reference for clinical treatment.

Methods

A total of 82 elderly patients with type H hypertension who were admitted to our hospital from March to August 2017 were selected as the research subjects. The study included a 4-week continuous irrigation period followed by a 24-week randomized treatment period. Forty patients in the valsartan group and 42 in the amlodipine group were treated with 5 mg amlodipine or 80 mg valsartan for 24 weeks. Clinical efficacy, 24 h mean DBP, SBP, and 24HSBP, DBP coefficient of variation, cardiac fatty acid-binding protein (H-FABP), vascular pseudohemophilia factor (VWF), nitric oxide (NO), endothelium-dependent vasodilation function (FMD), nonendothelium-dependent vasodilation function (NMD), malondialdehyde (MDA), GSH-Px, and SOD levels were observed.

Results

The total effective rate was 80.0% (32/40) in the valsartan group and 85.71% (36/42) in the amlodipine group, and the difference was not statistically significant (P > 0.05). After 24 weeks of treatment, the 24 h mean SBP, SDP, 24HSBP, and DBP variation coefficients of the two groups were significantly decreased, and there was no statistical significance between the two groups (P > 0.05). After treatment, the values of H-FABP, VWF, NO, and MDA in both groups decreased compared with before treatment, while the values of FMD%, NMD%, SOD, and GSH-Px increased compared with before treatment (P > 0.05), and the levels of H-FABP, VWF, and NO in the valsartan group were lower than those in the amlodipine group. Meanwhile, FMD%, NMD%, SOD, and GSH-Px levels were higher than those in the amlodipine group (P > 0.05).

Conclusion

Valsartan and amlodipine reduce blood pressure, improve vascular endothelial function, and inhibit oxidative stress in elderly patients with H-type hypertension on average. However, valsartan has a better effect on vascular endothelial dysfunction and oxidative stress in elderly patients with H-type hypertension.

Reno protective role of amlodipine in patients with hypertensive chronic kidney disease

Chronic kidney disease (CKD) and hypertension (HTN) are closely associated with an overlapping and intermingled cause and effect relationship. Decline in renal functions are usually associated with a rise in blood pressure (BP), and prolonged elevations in BP hasten the progression of kidney function decline. Regulation of HTN by normalizing the BP in an individual, thereby slowing the progression of kidney disease and reducing the risk of cardiovascular disease, can be effectively achieved by the anti-hypertensive use of calcium channel blockers (CCBs). Use of dihydropyridine CCBs such as amlodipine (ALM) in patients with CKD is an attractive option not only for controlling BP but also for safely improving patient outcomes. Vast clinical experiences with its use as monotherapy and/or in combination with other anti-hypertensives in varied conditions have demonstrated its superior qualities in effectively managing HTN in patients with CKD with minimal adverse effects. In comparison to other counterparts, ALM displays robust reduction in risk of cardiovascular endpoints, particularly stroke, and in patients with renal impairment. ALM with its longer half-life displays effective BP control over 24-h, thereby reducing the progression of end-stage-renal disease. In conclusion, compared to other classes of CCBs, ALM is an attractive choice for effectively managing HTN in CKD patients and improving the overall quality of life.

Advances in the pathogenesis and prevention of contrast-induced nephropathy

With the increasing application of medical imaging contrast materials, contrast-induced nephropathy has become one of the leading causes of iatrogenic renal insufficiency. The underlying mechanism is associated with renal medullary hypoxia, direct toxicity of contrast agents, oxidative stress, apoptosis, immune/inflammation and epigenetic regulation in contrast-induced nephropathy. Up to date, there is no effective therapy for contrast-induced nephropathy, and thus risk predication and effective preventive strategies are keys to reduce the occurrence of contrast-induced nephropathy. It was found that the proper use of contrast medium, personalized hydration, and high-dose statins may reduce the occurrence of contrast-induced nephropathy, while antioxidants have not shown significant therapeutic benefits. Additionally, the role of remote ischemia preconditioning and vasodilators in the prevention of contrast-induced nephropathy needs further study. This review aims to discuss the incidence, pathogenesis, risk prediction, and preventive strategies for contrast-induced nephropathy.