Azelnidipine Attenuates Cardiovascular and Sympathetic Responses to Air-Jet Stress in Genetically Hypertensive Rats

Efficacy and Safety of Azelnidipine as an Antihypertensive Compared to Amlodipine: A Systematic Review and Meta-analysis

INTRODUCTION

Azelnidipine is one of the newer Calcium Channel Blockers (CCB) approved in China, Japan, and India. Some studies have found that the blood pressure-lowering effect of azelnidipine is more than amlodipine, and others found the effect similar.

AIM

This meta-analysis was conducted to evaluate the efficacy of azelnidipine in managing hypertensive patients by lowering Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), and Heart Rate (HR) as compared to amlodipine.

METHODS

PubMed/MEDLINE, Google Scholar, PROQUEST, and International Clinical Trial Registry Platform (ICTRP) were searched for published articles to evaluate the clinical efficacy of azelnidipine in the management of hypertension patients. Data were extracted from the selected 11 randomized clinical trials (RCTs). The risk of bias 2 (RoB2) tool was used for the quality assessment of the included studies, and the random-effects model was used to estimate the effect size.

RESULTS

There were no statistically significant differences in the reduction of SBP (Mean Difference, MD: - 1.07; 95% CI: - 4.10, 1.95, p-value: 0.49) and DBP (MD: 0.27; 95% CI: - 2.66, 3.20, p-value: 0.86) between both the drugs. In terms of HR reduction, there was a statistically significant difference (MD: - 3.63; 95% CI: - 5.27, - 2.00, p-value: < 0.0001) between both drugs. Egger's test excluded any publication bias for the included studies (p = 0.21). Meta-regression excluded the effect of the duration of treatment on outcome parameters.

CONCLUSION

Though no significant difference between azelnidipine and amlodipine was found, in terms of reduction in SBP and DBP, azelnidipine reduced heart rate significantly compared to amlodipine.

PROSPERO REGISTRATION

CRD42023390361.

Potential protective effects of Azelnidipine against cerebral ischemia-reperfusion injury in male rats

This study was performed to evaluate the neuroprotective effect of Azelnidipine in cerebral ischemia/reperfusion and to envisage its mechanisms. Twenty-eight adult male Sprague-Dawley rats weighing 200-300 g were randomized into 4 groups (7 rats in each group). Sham (neck dissection without bilateral common carotid artery occlusion), control (30 minutes of bilateral common carotid artery occlusion and reperfusion for 1 hour), vehicle (identical volume of 0.3% carboxymethylcellulose (CMC) orally every day then bilateral common artery occlusion and reperfusion), and Azelnipine-treated rats (7 days of Azelnidipine pretreatment 3 mg/kg/day followed by bilateral common carotid artery occlusion and reperfusion). In addition to brain infarct volume and histopathological assessment, the brain tissues were harvested to evaluate cerebral IL-6, IL-10, TNF-α, ICAM-1, NF-κB p65, and total antioxidant capacity levels. Cerebral levels of IL-6, IL-10, TNF-α, NF-κB p65, and ICAM-1, besides cerebral infarct volume, were significantly elevated in control and vehicle related to sham groups, while total antioxidant capacity was markedly reduced. Azelnidipine treatment resulted in remarkable upregulation of total antioxidant capacity; meanwhile, IL-6, TNF-α, NF-κB p65, and ICAM-1 showed a considerable reduction. Cerebral IL-10 levels were not affected by Azelnidipine pretreatment. Histologically, control and vehicle rats showed severe ischemic injury, which was greatly reversed by Azelnidipine treatment. The current study disclosed that Azelnidipine could markedly reduce cerebral infarct volume and ameliorate histopathological damage in male rats exposed to cerebral ischemia/reperfusion. The neuroprotective effects of Azelnidipine probably stemmed from its anti-inflammatory and antioxidative properties. Azelnidipine had no effect on cerebral IL-10 levels.

Effect of iron oxide nanoparticles on vascular function and nitric oxide production in acute stress-exposed rats

We investigated whether polyethylene glycol-coated Fe3O4 nanoparticles (IONs), acute stress and their combination modifies vascular functions, nitric oxide synthase (NOS) activity, mean arterial pressure (MAP) as well as hepcidin and ferritin H gene expressions in Wistar-Kyoto rats. Rats were divided into control, ION-treated rats (1 mg Fe/kg i.v.), repeated acute air-jet stress-exposed rats and IONs-and-stress co-exposed rats. Maximal acetylcholine (ACh)-induced and sodium nitroprusside (SNP)-induced relaxations in the femoral arteries did not differ among the groups. IONs alone significantly elevated the N?-nitro-L-arginine methyl ester (L-NAME)-sensitive component of ACh-induced relaxation and reduced the sensitivity of vascular smooth muscle cells to SNP. IONs alone also elevated NOS activity in the brainstem and hypothalamus, reduced NOS activity in the kidneys and had no effect in the liver. Acute stress alone failed to affect vascular function and NOS activities in all the tissues investigated but it elevated ferritin H expression in the liver. In the ION-and-stress group, NOS activity was elevated in the kidneys and liver, but reduced in the brainstem and hypothalamus vs. IONs alone. IONs also accentuated air-jet stress-induced MAP responses vs. stress alone. Interestingly, stress reduced ION-originated iron content in blood and liver while it was elevated in the kidneys. In conclusion, the results showed that 1) acute administration of IONs altered vascular function, increased L-NAME-sensitive component of ACh-induced relaxation and had tissue-dependent effects on NOS activity, 2) ION effects were considerably reduced by co-exposure to repeated acute stress, likely related to decrease of ION-originated iron in blood due to elevated decomposition and/or excretion.

Lack of Reactive Oxygen Species Deteriorates Blood Pressure Regulation in Acute Stress

This study investigated the contribution of reactive oxygen species (ROS) to blood pressure regulation in conscious adult male Wistar rats exposed to acute stress. Role of ROS was investigated in rats with temporally impaired principal blood pressure regulation systems using ganglionic blocker pentolinium (P, 5 mg/kg), angiotensin converting enzyme inhibitor captopril (C, 10 mg/kg), nitric oxide synthase inhibitor L-NAME (L, 30 mg/kg) and superoxide dismutase mimeticum tempol (T, 25 mg/kg). Mean arterial pressure (MAP) was measured by the carotid artery catheter and inhibitors were administered intravenously. MAP was disturbed by a 3-s air jet, which increased MAP by 35.2±3.0 % vs. basal MAP after the first exposure. Air jet increased MAP in captopril- and tempol-treated rats similarly as observed in saline-treated rats. In pentolinium-treated rats stress significantly decreased MAP vs. pre-stress value. In L-NAME-treated rats stress failed to affect MAP significantly. Treatment of rats with P+L+C resulted in stress-induced MAP decrease by 17.3±1.3 % vs. pre-stress value and settling time (20.1±4.2 s). In P+L+C+T-treated rats stress led to maximal MAP decrease by 26.4±2.2 % (p<0.005 vs. P+L+C) and prolongation of settling time to 32.6±3.3 s (p<0.05 vs. P+L+C). Area under the MAP curve was significantly smaller in P+L+C-treated rats compared to P+L+C+T-treated ones (167±43 vs. 433±69 a.u., p<0.008). In conclusion, in rats with temporally impaired blood pressure regulation, the lack of ROS resulted in greater stress-induced MAP alterations and prolongation of time required to reach new post-stress steady state.

Continuous hypertension and tachycardia after resection of a hemangioblastoma behind the dorsal medulla oblongata: relationship to sympathetic overactivity at the neurogenic vasomotor center

A very rare case of continuous hypertension and tachycardia after excision of a cerebellar hemangioblastoma at the dorsal medulla oblongata is presented. This 21-year-old man was admitted to the authors' hospital with a headache and dizziness. Radiological examination revealed a tumor located behind the dorsal medulla oblongata and compressing it substantially. The tumor was completely resected, but after the surgery the patient experienced prolonged hypertension and tachycardia. Postoperative MR imaging showed a small injury at the dorsocaudal medulla that was located at the caudal site of the nucleus of the tractus solitarius (NTS). Because the NTS has been reported to play a central role in cardiovascular regulation along with the rostral ventrolateral medulla, the authors considered it possible that the NTS injury was the cause of the prolonged elevation of sympathetic tone.