Magnesium attenuates endothelin-1-induced vasoreactivity and enhances vasodilatation in mouse pulmonary arteries: Modulation by chronic hypoxic pulmonary hypertension

Zinc attenuates monocrotaline-induced pulmonary hypertension in rats through upregulation of A20

Pulmonary hypertension (PH) is characterized by excessive proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs), in which inflammatory signaling caused by activation of the NF-κB pathway plays an important role. A20 is an important negative regulator of the NF-κB pathway, and zinc promotes the expression of A20 and exerts a protective effect against various diseases (e.g. COVID19) by inhibiting the inflammatory signaling. The role of A20 and intracellular zinc signaling in PH has been explored, but the extracellular zinc signaling is not well understood, and whether zinc has protective effects on PH is still elusive. Using inductively coupled plasma mass spectrometry (ICP-MS), we studied the alteration of trace elements during the progression of monocrotaline (MCT)-induced PH and found that serum zinc concentration was decreased with the onset of PH accompanied by abnormalities of other three elements, including copper, chromium, and magnesium. Zinc chloride injection with the dosage of 5 mg/kg intraperitoneally partially corrected this abnormality and inhibited the progression of PH. Zinc supplementation induced the expression of A20 in lung tissue and reduce the inflammatory responses. In vitro, zinc supplementation time-dependently upregulated the expression of A20 in PASMCs, therefore correcting the excessive proliferation and migration of cells caused by hypoxia. Using genetically encoded-FRET based zinc probe, we found that these effects of zinc ions are not achieved by entering cells, but most likely by activating cell surface zinc receptor (ZnR/GPR39). These results provide the first evidence of the effectiveness of zinc supplementation in the treatment of PH.

Role of Magnesium, Effects of Hypomagnesemia, and Benefits of Magnesium Supplements in Cardiovascular and Chronic Kidney Diseases

Cardiovascular diseases (CVDs) account for nearly half of chronic kidney disease (CKD)-related deaths. Hypomagnesemia has been associated with various cardiovascular conditions and predicts a decline in renal function leading to end-stage renal disease (ESRD). The objective of this review is to delve into and discuss the significance of magnesium (Mg) in cardiovascular and renal functions, the clinical consequences of hypomagnesemia on CVD and CKD, and the benefits of Mg supplementation in managing CVD and CKD. This review is the result of an extensive search for pertinent articles in databases like PubMed, Medline, PubMed Central, and Google Scholar. Based on the literature search conducted in this review, we concluded that Mg protects against various CVDs and delays the progression of CKD. Mg can regulate pathways associated with inflammation, oxidative stress, and fibrosis. Therefore, maintaining slightly elevated Mg levels and timely Mg supplementation may benefit patients with CVD and CKD. There is a need for additional prospective randomized controlled trials to fully comprehend the therapeutic effects of Mg on CVD and CKD along with setting individualized target levels for serum Mg in such patients.

Study on the mechanism of magnesium calcium alloys/mineralized collagen composites mediating macrophage polarization to promote bone repair

Magnesium-based composites are a focal point in biomaterials research. However, the rapid degradation rate of magnesium alloys does not align with the healing time of bone tissue. Additionally, the host reaction caused by magnesium implantation hampers its full osteogenic potential. To maintain an appropriate microenvironment, it is important to enhance both corrosion resistance and osteogenic activity of the magnesium matrix. In this study, a composite scaffold composed of mineralized collagen and magnesium alloy was utilized to investigate the regulatory effect of mineralized collagen on mouse macrophages and evaluate its impact on mouse bone marrow mesenchymal stem cells in terms of osteogenesis, immune response, and macrophage-induced osteogenic differentiation. This experiment examined the biocompatibility of mouse bone marrow mesenchymal stem cells and macrophage-induced osteogenic differentiation in vitro, and examined the expression levels of relevant pathways proteins. Magnesium calcium alloys/mineralized collagen exhibited extensive spreading, facilitated by broad and abundant pseudopodia that firmly adhered them to the material surface and promoted growth and pseudopodia formation. The findings revealed that magnesium calcium alloy/mineralized collagen scaffold materials induced osteogenic differentiation mainly through M2 polarization of macrophages. This effect was mainly mediated by promoting the integrin α2β1-FAK-ERK1/2 signaling pathways and inhibiting the RANK signaling pathways.

Post-transfusion severe headache in a patient with thalassemia with superficial siderosis of the central nervous system: a case report and literature review

BACKGROUND

Patients with severe thalassemia may experience adverse effects from transfusion such as fever, rash, and iron overload after long-term transfusion therapy. Severe headaches as a side effect of blood transfusion in patients with thalassemia are not commonly observed, especially when combined with superficial siderosis of the central nervous system, which is easily misdiagnosed and requires excessive examination and treatment.

CASE PRESENTATION

A 31-year-old woman was admitted with severe headache and vomiting over 3 days following blood transfusion. She was diagnosed with intermediate α-thalassemia at 2 years of age and had a history of irregular blood transfusions. Physical examination revealed horizontal nystagmus with no other abnormal neurological signs. Magnetic resonance (MR) imaging, MR venography, MR arteriography, and cerebrospinal fluid analysis were normal. However, susceptibility-weighted imaging showed abnormal signals in the bilateral and fourth ventricles. Initial antibiotics, antivirals, decompression of intracranial pressure, iron chelation, and symptomatic treatments were administered; subsequently, small intermittent blood transfusions were cautiously administered for severe anemia. The patient's headache was gradually relieved, and she was discharged on day 9. At the 5-month follow-up, the patient's headache recurred following another transfusion.

CONCLUSIONS

Severe post-transfusion headache in patients with thalassemia has not been fully recognized and is easily misdiagnosed, leading to excessive examination and treatment. Understanding the clinical features of transfusion-related headaches can help identify this complication, but the exact pathophysiological mechanism requires further research.

Research on the Current Application Status of Magnesium Metal Stents in Human Luminal Cavities

The human body comprises various tubular structures that have essential functions in different bodily systems. These structures are responsible for transporting food, liquids, waste, and other substances throughout the body. However, factors such as inflammation, tumors, stones, infections, or the accumulation of substances can lead to the narrowing or blockage of these tubular structures, which can impair the normal function of the corresponding organs or tissues. To address luminal obstructions, stenting is a commonly used treatment. However, to minimize complications associated with the long-term implantation of permanent stents, there is an increasing demand for biodegradable stents (BDS). Magnesium (Mg) metal is an exceptional choice for creating BDS due to its degradability, good mechanical properties, and biocompatibility. Currently, the Magmaris® coronary stents and UNITY-BTM biliary stent have obtained Conformité Européene (CE) certification. Moreover, there are several other types of stents undergoing research and development as well as clinical trials. In this review, we discuss the required degradation cycle and the specific properties (anti-inflammatory effect, antibacterial effect, etc.) of BDS in different lumen areas based on the biocompatibility and degradability of currently available magnesium-based scaffolds. We also offer potential insights into the future development of BDS.

Pulmonary Vascular Remodeling in Pulmonary Hypertension

Pulmonary vascular remodeling is the critical structural alteration and pathological feature in pulmonary hypertension (PH) and involves changes in the intima, media and adventitia. Pulmonary vascular remodeling consists of the proliferation and phenotypic transformation of pulmonary artery endothelial cells (PAECs) and pulmonary artery smooth muscle cells (PASMCs) of the middle membranous pulmonary artery, as well as complex interactions involving external layer pulmonary artery fibroblasts (PAFs) and extracellular matrix (ECM). Inflammatory mechanisms, apoptosis and other factors in the vascular wall are influenced by different mechanisms that likely act in concert to drive disease progression. This article reviews these pathological changes and highlights some pathogenetic mechanisms involved in the remodeling process.

Magnesium ions improve vasomotor function in exhausted rats

To observe the effect of magnesium ion on vascular function in rats after long-term exhaustive exercise. Forty male SD rats were divided into two groups, the control group (CON group, n = 20) and the exhaustive exercise group (EEE group, n = 20). Exhausted rats performed 1W adaptive swimming exercise (6 times/W, 15min/time), and then followed by 3W formal exhaustive exercise intervention. Hematoxylin and eosin (HE) staining was used to detect the morphological changes of rat thoracic aorta. The contents of interleukin-1 β (IL-1β) and tumor necrosis factor-α (TNF-α) in serum of rats were determined by enzyme-linked immunosorbent assay (ELISA), and the contents of malondialdehyde (MDA), reactive oxygen species (ROS), nitric oxide (NO) and endothelin 1 (ET-1) in serum of rats were determined by biochemical kit. Vascular ring test detects vascular function. Compared with the CON group, the smooth muscle layer of the EEE group became thicker, the cell arrangement was disordered, and the integrity of endothelial cells was destroyed; the serum Mg2+ in EEE group was decreased; the serum levels of IL-1β, TNF-α, MDA and ROS in EEE group were significantly higher than those in the CON group (P are all less than 0.05); the serum NO content in EEE group was significantly decreased, and the ratio of NO/ET-1 was significantly decreased. In the exhaustion group, the vasoconstriction response to KCl was increased, and the relaxation response to Ach was weakened, while 4.8mM Mg2+ could significantly improve this phenomenon (P are all less than 0.01). The damage of vascular morphology and function in rats after exhaustion exercise may be related to the significant increase of serum IL-1β, TNF-α, ROS, MDA and ET-1/NO ratio in rats after exhaustion exercise, while Mg2+ can significantly improve the vasomotor function of rats after exhaustion exercise.

The bioresorbable magnesium scaffold (Magmaris)-State of the art: From basic concept to clinical application

Since its introduction to clinical practice, coronary artery stent implantation has become a crucial part of the therapy of coronary artery disease (CAD). Despite the undeniable evolution of percutaneous coronary revascularization procedures, drug-eluting stent (DES) technology shows some limitations. To overcome these limitations bioresorbable vascular scaffolds (BRS) were designed as a vessel-supporting technology allowing for anatomical and functional restoration of the vessel after the scaffold intended resorption. Various materials have been proposed as the basis of the scaffold backbone. In this narrative review, we present second-generation magnesium-alloy bioresorbable scaffold devices (Magmaris; Biotronik). Additionally, we discuss available preclinical and clinical data regarding this new magnesium BRS.

Magnesium and Its Role in Primary Open Angle Glaucoma; A Novel Therapeutic?

Glaucoma is the leading cause of irreversible blindness globally, with Primary open angle glaucoma (POAG) being the commonest subtype. POAG is characterized by an increase in intraocular pressure (IOP), leading to optic nerve damage and subsequent visual field defects. Despite the clinical burden this disease poses, current therapies aim to reduce IOP rather than targeting the underling pathogenesis. Although the pathogenesis of POAG is complex, the culprit for this increase in IOP resides in the aqueous humour (AH) outflow pathway; the trabecular meshwork (TM) and Schlemm's canal. Dysfunction in these tissues is due to inherent mitochondrial dysfunction, calcium influx sensitivity, increase in reactive oxygen species (ROS) production, TGFβ-2 induction, leading to a sustained inflammatory response. Magnesium is the second most common intracellular cation, and is a major co-factor in over 300 reactions, being highly conserved within energy-dependent organelles such as the mitochondria. Magnesium deficiency has been observed in POAG and is linked to inflammatory and fibrotic responses, as well as increased oxidative stress (OS). Magnesium supplementation been shown to reduce cellular ROS, alleviate mitochondrial dysregulation and has further antifibrotic and anti-inflammatory properties within ocular tissues, and other soft tissues prone to fibrosis, suggesting that magnesium can improve visual fields in patients with POAG. The link between magnesium deficiency and glaucoma pathogenesis as well as the potential role of magnesium supplementation in the management of patients with POAG will be explored within this review.

High magnesium mitigates the vasoconstriction mediated by different types of calcium influx from monocrotaline-induced pulmonary hypertensive rats

NEW FINDINGS

What is the central question of this study? The aim was to examine and explore the involvement of Mg²⁺ in mitigating the vasoconstriction in PAs and sPAs in the MCT-PAH rat model. What are the main finding and its importance? 1.Both SOCE- and ROCE-mediated vasoconstriction enhanced in the MCT-PAH model. 2.High magnesium inhibited vasoconstriction due to directly antagonizing Ca²⁺ and increasing NO release. 3.The inhibition effect of high magnesium was more notable in sPA.

ABSTRACT

Increased extracellular magnesium concentration ([Mg²⁺ ]_e ) has been evidenced to attenuate the endothelin-1 (ET-1)-induced contractile response via the release of nitric oxide (NO) from the endothelium in proximal pulmonary arteries (PAs) of chronic hypoxic (CH) mice. Here we further examined the involvement of Mg²⁺ in the inhibition of vasoconstriction in PAs and distal smaller pulmonary arteries (sPAs) in a monocrotaline-induced pulmonary arterial hypertension (MCT-PAH) rat model. The data showed that in control rats, vasoconstriction in sPAs is more intense than that in PAs. In MCT-PAH rats, the store-operated Ca²⁺ entry (SOCE)-, and receptor-operated Ca²⁺ entry (ROCE)-mediated contraction was significantly strengthened. However, there was no upregulation of the vasoconstriction mediated by voltage-dependent calcium entry (VDCE). Furthermore, high magnesium greatly inhibited the VDCE-mediated contraction in PAs instead of sPAs, which was opposite to the ROCE-mediated contraction. Moreover, MCT pretreatment partly eliminated the endothelium-dependent vasodilation in PAs, which in sPAs, however, was still promoted by magnesium due to the increased NO release in pulmonary microvascular endothelial cells (PMVECs). In conclusion, the findings suggest that both SOCE- and ROCE-mediated vasoconstriction in the MCT-PAH model are enhanced, especially in sPAs. The inhibition effect of high magnesium on vasoconstriction can be achieved partly by its direct role as a Ca²⁺ antagonist and partly by increasing the NO release in PMVECs. This article is protected by copyright. All rights reserved.

Custodiol-MP for ex vivo lung perfusion - A comparison in a porcine model of donation after circulatory determination of death

INTRODUCTION

Ex vivo lung perfusion (EVLP) is an established technique to evaluate and eventually recondition lungs prior to transplantation. Custodiol-MP (C-MP) solution is a new solution, designed for clinical machine perfusion, that has been used for kidneys. The aim of this study was to compare the effects of EVLP with Custodiol-MP on lung functional outcomes to the gold standard of EVLP with Steen Solution™.

MATERIAL AND METHODS

In a porcine EVLP model of DCDD (Donation after Circulatory Determination of Death), lungs were perfused with Steen Solution™ (SS, n = 7) or Custodiol-MP solution supplemented with 55 g/l albumin (C-MP, n = 8). Lungs were stored cold for 4 h in low potassium dextran solution and subsequently perfused ex vivo for 4 h. During EVLP pulmonary gas exchange, activities of lactate dehydrogenase (LDH) and alkaline phosphatase (AP) as well as levels of lactate in the perfusate were recorded hourly.

RESULTS

Oxygenation capacity differed significantly between groups (averaged over 4 h: SS 274 ± 178 mmHg; C-MP 284 ± 151 mmHg p = 0.025). Lactate dehydrogenase activities and lactate concentrations were significantly lower in Custodiol-MP perfused lungs.In a porcine model of DCDD with 4 h of EVLP the use of modified Custodiol-MP as perfusion solution was feasible. The use of C-MP showed at least comparable lung functional outcomes to the use of Steen SolutionTM. Furthermore C-MP perfusion resulted in significantly lower lactate dehydrogenase activity and lactate levels in the perfusate and higher oxygenation capacity.

Qingda Granule Attenuates Angiotensin II-Induced Blood Pressure and Inhibits Ca2+/ERK Signaling Pathway

Objective: As a well-known traditional Chinese medicine formula prescribed by academician Ke-ji Chen, Qingda granule (QDG) lowered the blood pressure of spontaneously hypertensive rats and attenuated hypertensive cardiac remodeling and inflammation. However, its functional role and underlying mechanisms on hypertensive vascular function remain largely unclear. This study aims to assess the effects of QDG treatment on Angiotensin II- (AngII-) induced hypertension and vascular function and explore its underlying mechanisms both in vitro and in vivo.

Methods: In an in vivo study, 25 male C57BL/6 mice were randomly divided into five groups, including Control, AngII, AngII + QDG-L, AngII + QDG-M, and AngII + QDG-H groups (n = 5 for each group). Mice in AngII and AngII + QDG-L/-M/-H groups were infused with AngII (500 ng/kg/min), while in the Control group, they were infused with saline. Mice in AngII + QDG were intragastrically given different concentrations of QDG (0.5725, 1.145, or 2.29 g/kg/day), while in Control and AngII groups, they were intragastrically given equal volumes of double distilled water for 2 weeks. Blood pressure was determined at 0, 1, and 2 weeks of treatment. Ultrasound was used to detect the pulse wave velocity (PWV) and HE staining to detect the pathological change of the abdominal aorta. RNA sequencing (RNA-seq) was performed to identify the differentially expressed transcripts (DETs) and related signaling pathways. IHC was used to detect the expression of p-ERK in the abdominal aorta. Primary isolated rat vascular smooth muscle cells (VSMCs) were used to assess the cellular Ca²⁺ release and activation of the ERK pathway by confocal microscope and western blotting analysis, respectively.

Results: QDG treatment significantly alleviated the elevated blood pressure, the PWV, and the thickness of the abdominal aorta in AngII-induced hypertensive mice. RNA-seq and KEGG analyses identified 1,505 DETs and multiple enriched pathways (including vascular contraction and calcium signaling pathway) after QDG treatment. Furthermore, confocal microscope showed that QDG treatment partially attenuated the increase of Ca²⁺ release with the stimulation of AngII in cultured VSMCs. In addition, IHC and western blotting indicated that QDG treatment also partially alleviated the increase of phospho-ERK levels in abdominal aorta tissues of mice and cultured VSMCs after the infusion or stimulation of AngII.

Conclusion: QDG treatment attenuated the elevation of blood pressure, abdominal aorta dysfunction, pathological changes, Ca²⁺ release, and activation of the ERK signaling pathway.

Magnesium Supplementation Attenuates Pulmonary Hypertension via Regulation of Magnesium Transporters

Pulmonary hypertension (PH) is characterized by profound vascular remodeling and altered Ca²⁺ homeostasis in pulmonary arterial smooth muscle cells (PASMCs). Magnesium ion (Mg²⁺), a natural Ca²⁺ antagonist and a cofactor for numerous enzymes, is crucial for regulating diverse cellular functions, but its roles in PH remains unclear. Here, we examined the roles of Mg²⁺ and its transporters in PH development. Chronic hypoxia and monocrotaline induced significant PH in adult male rats. It was associated with a reduction of [Mg²⁺]_i in PASMCs, a significant increase in gene expressions of Cnnm2, Hip14, Hip14l, Magt1, Mmgt1, Mrs2, Nipa1, Nipa2, Slc41a1, Slc41a2 and Trpm7; upregulation of SLC41A1, SLC41A2, CNNM2, and TRPM7 proteins; and downregulation of SLC41A3 mRNA and protein. Mg²⁺ supplement attenuated pulmonary arterial pressure, right heart hypertrophy, and medial wall thickening of pulmonary arteries, and reversed the changes in the expression of Mg²⁺ transporters. Incubation of PASMCs with a high concentration of Mg²⁺ markedly inhibited PASMC proliferation and migration, and increased apoptosis, whereas a low level of Mg²⁺ produced the opposite effects. siRNA targeting Slc41a1/2, Cnnm2, and Trpm7 attenuated PASMC proliferation and migration, but promoted apoptosis; and Slc41a3 overexpression also caused similar effects. Moreover, siRNA targeting Slc41a1 or high [Mg²⁺] incubation inhibited hypoxia-induced upregulation and nuclear translocation of NFATc3 in PASMCs. The results, for the first time, provide the supportive evidence that Mg²⁺ transporters participate in the development of PH by modulating PASMC proliferation, migration, and apoptosis; and Mg²⁺ supplementation attenuates PH through regulation of Mg²⁺ transporters involving the NFATc3 signaling pathway.

Synchronous detection of vascular tension and nitric oxide release in pulmonary artery: A combined application of confocal wire myograph with confocal laser scanning microscopy

OBJECTIVES

To detect the vascular tension and nitric oxide (NO) release synchronously in mice pulmonary artery, we perform two experiments and present a novel application of confocal wire myograph coupled with the confocal laser scanning microscopy.

METHODS

In the first experiment, viable endothelium-intact mouse pulmonary artery (outer diameter 100-300 μM) rings underwent a one-hour preincubation with a NO-specific fluorescent dye, 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate Calbiochem (2.5 μM), and then precontracted with phenylephrine (Phen, 10^-6 M), and subsequently dilated in acetylcholine (ACh, 10^-6 M - 10^-4 M). The endothelium-dependent vasorelaxation and NO generation in pulmonary artery rings were simultaneously recorded. In the second experiment, after 30-min incubation with the former NO fluorescent dye, the qualified pulmonary artery rings were co-incubated for another 30 min with a nitric oxide synthase inhibitor, 10^-4 M Nω-nitro-L-arginine-methyl-ester (L-NAME), and then pretreated with Phen (10^-6 M) followed by ACh (10^-5 M). The Ach-induced vasodilation and NO release were recorded simultaneously.

RESULTS

ACh (10^-6 M - 10^-4 M) promoted pulmonary artery relaxation and intracellular NO release in a dose-dependent manner. Additionally, L-NAME (10^-4 M) significantly attenuated the vasodilatation and the intracellular NO release.

CONCLUSIONS

This combined application visually confirms that the synchronous changes in Ach induced vasodilation and NO release, which provides a new method for cardiovascular research.

Expression of pulmonary arterial elastin in rats with hypoxic pulmonary hypertension using H2S

Object: This study analyses the changes of pulmonary arterial elastin expression inhibited by hydrogen sulfide (H2S) in rats with hypoxic pulmonary hypertension.Method: The research used 30 healthy rats and randomly divided them into control group, hypoxia group, and hypoxia + sodium hydrosulfide group. Each group contains 10 samples. The right catheterization was selected to measure the mean pulmonary artery pressure (mPAP). The RV/LV + S ratio was calculated through separating the right ventricle and the left ventricle plus the interventricular septum. Optical microscopy was used to observe the changes of pulmonary vascular structure. The research used immunohistochemistry to express the levels of elastin and transforming growth factor beta (TGF-β).Results: The ratios of Mpap and RV/LV + S in the hypoxic group exceed the control group. The hypoxia + sodium hydrosulfide group (hypoxia + NaHS) is lower than the hypoxic group. In the hypoxic group, the elastic expressions of medium and small pulmonary artery smooth muscle cells exceed the control group. The expression of elastin in hypoxic + NaHS medium and small pulmonary artery smooth muscle cells is lower than that of the control group.The protein expression levels of α-SM-actin in muscle arterial smooth muscle of pulmonary arterioles in hypoxic group, control group and hypoxic + NaHS group were 49.84% + 6.27%, 56.84% + 6.38%, 23.82% + 3.84%, 27.51% + 3.24%, 29.00% + 4.05%, 34.72% + 3.38%.Conclusion: Hydrogen sulfide in rats with hypoxic pulmonary hypertension can inhibit the expression of elastin in its extracellular matrix, which also has remarkable regulation function in forming HPH and remodeling hypoxic pulmonary vascular structure.

Increased caveolin-1 expression enhances the receptor-operated Ca2+ entry in the aorta of two-kidney, one-clip hypertensive rats

NEW FINDINGS

What is the central question of this study? The aim was to examine and compare the contributions of caveolin-1 to the contractile responses mediated by L-type voltage-dependent calcium channels, store-operated Ca²⁺ channels and receptor-operated Ca²⁺ channels in two different types of arteries from two-kidney, one-clip hypertensive rats. What is the main finding and its importance? We demonstrated that the density of caveolae and caveolin-1 expression were significantly upregulated in the aorta of two-kidney, one-clip hypertensive rats, but not in the third-order branches of mesenteric arteries. We highlight that caveolin-1 plays an important role in aortic constriction by enhancing receptor-operated Ca²⁺ entry in the hypertensive rat model.

ABSTRACT

Calcium and its multiple regulatory mechanisms are crucial for the development of hypertension. Among these regulatory mechanisms, store-operated Ca²⁺ entry (SOCE) and receptor-operated Ca²⁺ entry (ROCE) mediate agonist-induced calcium influx, contributing to vascular contraction. The SOCE and ROCE are regulated by a variety of mechanisms involving caveolin-1 (Cav1), which has been found to be strongly associated with hypertension in gene polymorphism. In the present study, we investigated the role of Cav1 during the enhanced activity of calcium channels in hypertensive arteries. We demonstrated that the expression level of Cav1 was significantly increased in the aorta of two-kidney, one-clip (2K1C) hypertensive rats. The disruption of caveolae by methyl-β-cyclodextrin did not cause a marked difference in agonist-induced vasoconstriction in the third-order branches of the mesenteric arteries but strongly suppressed the aortic contractile response to endothelin-1 in the 2K1C group, which was not found in the control group. The increase in Cav1 by introduction of Cav1 scaffolding domain enhancing peptide promoted the 1-oleoyl-2-acetyl-glycerol-induced ROCE in hypertensive aortic smooth muscle cells but did not enhance the cyclopiazonic acid-induced SOCE. In the resistance arteries, similar changes were not observed, and no statistical changes of Cav1 expression were evident in the third-order branches of the mesenteric arteries. Our results indicate that increased Cav1 expression might promote the altered [Ca²⁺ ]_i -induced aortic vasoreactivity by enhancing ROCE and be involved in the pathogenesis of hypertension.

Magnesium: A Magic Bullet for Cardiovascular Disease in Chronic Kidney Disease?

Magnesium is essential for many physiological functions in the human body. Its homeostasis involves dietary intake, absorption, uptake and release from bone, swifts between the intra- and extracellular compartment, and renal excretion. Renal excretion is mainly responsible for regulation of magnesium balance. In chronic kidney disease (CKD), for a long time the general policy has been limiting magnesium intake. However, this may not be appropriate for many patients. The reference ranges for magnesium are not necessarily optimal concentrations, and risks for insufficient magnesium intake exist in patients with CKD. In recent years, many observational studies have shown that higher (in the high range of “normal” or slightly above) magnesium concentrations are associated with better survival in CKD cohorts. This review gives an overview of epidemiological associations between magnesium and overall and cardiovascular survival in patients with CKD. In addition, potential mechanisms explaining the protective role of magnesium in clinical cardiovascular outcomes are described by reviewing evidence from in vitro studies, animal studies, and human intervention studies with non-clinical endpoints. This includes the role of magnesium in cardiac arrhythmia, heart failure, arterial calcification, and endothelial dysfunction. Possible future implications will be addressed, which will need prospective clinical trials with relevant clinical endpoints before these can be adopted in clinical practice.