Calcium Channel Research Articles

Comparative Analysis of First-Line Antihypertensive Treatment Classes

BackgroundThe best first-line monotherapy for hypertension remains uncertain, as current guidelines suggest that thiazides, angiotensin-converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARB), and calcium channel blockers (CCB) are appropriate in the absence of specific comorbidities. We aimed to compare the outcomes of first-line antihypertensive classes in a real-life setting with a long follow-up period. MethodsThis nationwide retrospective new-user cohort study included patients insured by the largest health maintenance organization in Israel. We included patients with a new diagnosis of hypertension between 2008 and 2021 who initiated treatment with a single first-line drug for hypertension. Outcomes were assessed with and without propensity score matching for confounding factors. The primary composite outcome was the first occurrence of myocardial infarction (MI), acute coronary syndrome (ACS), stroke, or heart failure (HF). ResultsA total of 97,639 patients initiated antihypertensive treatment with a single drug as first-line therapy. The most commonly prescribed class was ACEi/ARB (66,717, 68.3%), followed by CCBs (15,922, 16.3%), beta-blockers (BBs, 12,869, 13.2%), and thiazides (2,131, 2.2%). For the primary outcome, the hazard ratios (HRs) for BBs, CCBs, and ACEi/ARBs were 1.44 (95% CI 1.25 - 1.66), 1.10 (95% CI 0.96 - 1.27), and 1.13 (95% CI 0.99 - 1.29), respectively, when compared to thiazides. ConclusionWhen initiating pharmacotherapy for hypertension with a single drug, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and calcium channel blockers were associated with similar risk of MI, ACS, stroke, or HF when compared to thiazides, while beta-blockers were associated with increased risk.

Ziconotide and psychosis: from a case report to a scoping review

Ziconotide is a non-opioid analgesic that acts on N-type voltage-gated calcium channels. Despite its proven effectiveness in pain treatment, it can induce neuropsychiatric symptoms. The aim of this article is to present a case of psychosis secondary to ziconotide and to explore the variety of neuropsychiatric symptoms it produces, exploring the relationship between these symptoms and the mechanism of action of ziconotide. For this purpose, a clinical case is presented as well as a scoping review of other cases published in the scientific literature. A search on Web of Science, Pubmed and Embase databases was performed on December 11, 2023, following the criteria of the PRISMA-ScR Statement. The clinical case presented shows the variety of neuropsychiatric symptomatology that ziconotide can cause in the same patient. On the other hand, 13 papers were retrieved from the scoping review (9 case reports, 4 case series), which included 21 cases of patients treated with ziconotide who presented adverse effects ranging from psychotic symptoms to delirium. In conclusion, the variety of neuropsychiatric symptoms derived from ziconotide could be related to the blockade of N-type voltage-gated calcium channels in glutamatergic and GABAergic neurons, in turn affecting dopaminergic pathways.

Impact of the COVID-19 pandemic on initiation of antihypertensive drugs in Sweden: an interrupted time series study

ObjectivesAntihypertensives reduce the risk of myocardial infarction and stroke. Restrictions during the COVID-19 pandemic limited access to healthcare, which may have had a negative impact on drug prescribing. This study...

A 34-year-old woman with mucolipidosis type IV predisposing to a neuroendocrine tumor in the gastric fundus

Abstract Introduction/Objective Mucolipidosis type IV (MLIV) is a lysosomal storage disorder with a gastric phenotype. Patients develop achlorhydia and compensatory hypergastrinemia, with pathology showing vacuolated parietal cells with lysosomal inclusions. MLIV is caused by mutation of TRPML1, a lysosomal membrane calcium channel required for trafficking proton pumps to the apical surface in parietal cells. We report the first case of MLIV predisposing to a neuroendocrine tumor (NET). This novel finding could impact management of patients with this disease, who may require frequent monitoring for NETs. We also show that immunohistochemistry for TRPML1 and H+/K+ ATPase can be used in conjunction to identify gastric MLIV. We hope that our updated immunohistochemical tools can aid in diagnosis of this disease. Methods/Case Report 34-year-old woman with MLIV requiring endoscopic resection for an incidentally discovered gastric polyp. Pathology showed Grade 2 NET invasion into submucosa (pT1). Background mucosa showed markedly vacuolated parietal cells, ranging from unilocular to multilocular with up to 20 vacuoles per cell. We stained the patient’s and a control stomach with antibodies against the TRPML1 and H+/K+ ATPase proteins. The H+/K+ ATPase antibody highlighted healthy parietal cells in the control stomach with strong cytoplasmic signal, but strikingly outlined lysosomal inclusions in MLIV parietal cells. TRPML-1 antibody showed cytoplasmic staining in parietal cells in the control. However, TRPML-1 staining showed markedly decreased signal in the patient and nuclear staining, possibly representing mislocalization. Results (if a Case Study enter NA) NA Conclusion We present the first case of MLIV predisposing to a NET in the stomach. NETs have potential for metastatic spread with subsequent mortality risk. Clinicians should maintain suspicion for NET development in this population, and protocols for frequent surveillance should be considered. This is also the first report using immunohistochemistry for TRPML1 and H+/K+ ATPase in combination to identify affected parietal cells in MLIV. Possibly, these tools can be used in the future by pathologists to diagnose MLIV.

Formulation, Optimization, and Evaluation of Solid-lipid Formulation for Bioavailability Enhancement Utilizing Diltiazem Hydrochloride

Background: Cardiac arrhythmia is a health concern, requiring effective medication for proper treatment. Diltiazem hydrochloride (DTZ.HCL), a class IV anti-arrhythmic calcium channel blocker, was used as a model drug due to its ability to block Ca++ channels in the SA and AV nodes, reducing calcium entry into cardiac cells and subsequently decreasing the force of contraction and oxygen consumption by the heart. Despite its good oral absorption, DTZ.HCL bioavailability is reduced to approximately 40% due to extensive first-pass metabolism. A nano-enabled drug delivery system has the advantage of incorporating both lipophilic and hydrophilic drugs with improved physical stability and enhanced bioavailability. Objective: The objective of this study was to develop a solid-lipid formulation utilizing diltiazem hydrochloride and evaluate it for its bioavailability enhancement. Method: In the experimental study, SLNs were prepared using the microemulsion technique. A blend ratio (1:1) of lipid (stearic acid: compritol 888 ATO), span 80, PEG 200, and water was selected based on the microemulsion region obtained from the Triplot (4.1) ternary phase diagram. The hydrophilic drug diltiazem hydrochloride was incorporated into the lipid blend, and a preheated Smix was maintained at 80°C to obtain a transparent microemulsion, which then crystallized to form SLNs upon subsequent dispersion in cold water (1:25). Critical process parameters, including magnetic stirring speed, homogenizer speed, and probe sonication cycle, were optimized using Design Expert 10 software to achieve the desired particle size diameter, PDI, and entrapment efficiency. Results: The results revealed that the particle size and PDI were significantly influenced by the span 80 and PEG 200. An increase in the concentration of the lipid blend resulted in large particle sizes. The optimized formulation showed a particle size of 415.4±0.2 nm, PDI of 0.184±0.01, and zeta potential of -24.19±0.12 mV. These results were corroborated by DSC thermograms, which indicated reduced enthalpy associated with the reduced particle size of SLNs. Given that diltiazem hydrochloride is a hydrophilic drug with high water solubility, the entrapment efficiency was relatively 30.6% ±0.45. In vitro release studies demonstrated an initial burst release, followed by a sustained release of 85% over 24 hours. The optimized SLNs followed the Higuchi matrix model, with a coefficient of correlation (R²) value of 0.9369. Conclusion: Results concluded successful development of SLNs with improved bioavailability when compared by way of in-vitro method with marketed preparations.

Hypertrophic Cardiomyopathy as a Form of Heart Failure with Preserved Ejection Fraction: Diagnosis, Drugs, and Procedures

Hypertrophic cardiomyopathy (HCM) is a complex and heterogeneous cardiac disorder characterized by cardiac hypertrophy disproportionate to loading stimuli (e.g. hypertension or aortic stenosis). Diagnosing HCM requires a thorough examination of clinical symptoms, with echocardiography as the key initial imaging tool. Multimodality imaging further supports diagnosis, helps assess left ventricular outflow obstruction, and aids in risk stratification for sudden cardiac death. The cornerstone of HCM management remains pharmacological therapy with β-blockers and calcium channel blockers serving as first-line agents to alleviate symptoms and reduce left ventricular outflow tract obstruction. More recently, cardiac myosin inhibitors have revolutionized the treatment paradigm for obstructive HCM. Procedural interventions such as septal reduction therapy are reserved for refractory cases. Genetic testing and risk stratification for sudden cardiac death play a critical role in treatment decisions, guiding further testing in first-degree relatives and ICD implantation in high-risk individuals. Exercise recommendations have evolved based on recent data, challenging traditional restrictions and emphasizing individualized plans.

Choice Between Free Combination of Antihypertensive Agents and Fixed Dosed Combinations in the Treatment of Arterial Hypertension

Most patients with arterial hypertension require more than one antihypertensive drug for blood pressure target achievement. Some patients are recommended for a multi-pill antihypertensive regimen, others — treatment with fixed dosed combinations in one tablet. Analysis of elibrary and PubMed publications in the period mostly from 2014 to 2024 concerning the choice of two-component combined antihypertensive agents containing renin-angiotensin system inhibitor and diuretic or calcium channel blocker, revealed that fixed-dose combinations (FDC) use and taking one tablet once a day improves adherence to treatment and facilitates blood pressure control. Although the cost of FDC containing the renin-angiotensin-aldosterone system inhibitor and a thiazide/thiazide-like diuretic or calcium channel blocker is in most cases higher than the same drugs taken separately, the use of fixed combinations, increasing patient adherence to therapy, has clinical advantage in terms of the effectiveness of lowering blood pressure, which confirms their economic feasibility. On the other hand, the use of free combination therapy in two different tablets, when taken separately during the day, can sometimes provide a more sustained antihypertensive effect over 24 hours. Evidence of the effectiveness of blood pressure control for FDCs is often extrapolated from data on free combinations. In addition, FDCs are characterized by less detection of possible ineffectiveness of one of the components. The range of FDCs and the dosage ratios of the components presented in them is gradually expanding, but the choice among free combinations is still wider. In addition, the list of vital and essential drugs (VED) for 2024 does not contain FDCs for antihypertensive drugs, which excludes the possibility of free receiving them on a preferential basis and gives the opportunity for the manufacturer to set prices for them. Despite the fact that recently the scientific community has recommended the use of FDC antihypertensive drugs as initial therapy due to better compliance with the regimen, and therefore clinical effectiveness and economic feasibility, it cannot be said that there is no space left for free combinations of antihypertensive drugs in the treatment of arterial hypertension. The choice of doctor, frequency of prescription, share of purchases of the FDCs in the Russian Federation, review of their consumption requires further analysis.

Home blood pressure-lowering effect of esaxerenone versus trichlormethiazide for uncontrolled hypertension: a predefined subanalysis of the EXCITE-HT randomized controlled trial by basal calcium channel blocker versus angiotensin receptor blocker.

This prespecified subanalysis of the multicenter, randomized, open-label, parallel-group EXCITE-HT study aimed to examine the non-inferiority of esaxerenone to trichlormethiazide as a second-line antihypertensive agent according to the basal antihypertensive agent used (angiotensin receptor blocker [ARB] or calcium channel blocker [CCB]). The primary endpoint, change in morning home systolic/diastolic blood pressure (SBP/DBP) from baseline to end of treatment was similar between the two groups (intergroup difference in least squares mean change [95% confidence interval]: -1.3 [-3.8, 1.3]/-0.2 [-1.6, 1.3] mmHg for ARB; -2.7 [-4.2, -1.2]/-0.8 [-1.7, 0.1] mmHg for CCB). The respective incidences of serum potassium levels <3.5 mEq/L and ≥5.5 mEq/L in the ARB subgroup were 3.4% and 4.2% for esaxerenone and 7.9% and 0% for trichlormethiazide; in the CCB subgroup, they were 2.8% and 0.6% for esaxerenone and 13.9% and 1.2% for trichlormethiazide, respectively. The incidence of uric acid level ≥7.0 mg/dL was numerically higher in the trichlormethiazide group than the esaxerenone group in both the ARB and CCB subgroups. The non-inferiority of esaxerenone to trichlormethiazide in lowering morning home BP was demonstrated regardless of whether the basal antihypertensive agent was an ARB or CCB. Esaxerenone with a CCB showed superiority to trichlormethiazide in lowering SBP, without any new safety concerns. Serum potassium levels tended to be higher when esaxerenone was combined with an ARB than with a CCB, but this can be mitigated if administered according to the package insert. A subgroup analysis of the EXCITE-HT study according to basal antihypertensive agent demonstrated the non-inferiority of esaxerenone to trichlormethiazide in lowering morning home BP regardless irrespective of the basal antihypertensive agent. Esaxerenone with a CCB showed superiority to trichlormethiazide in lowering SBP, without any new safety concerns.

Toxicity of parental co-exposure of microplastic and bisphenol compounds on adult zebrafish: Multi-omics investigations on offspring

In recent years, the widespread use of bisphenol compounds and microplastics (MP) have attracted attention due to their harmful effects. Here, individual and combined effects of MP and bisphenol compounds, were assessed on adult zebrafish after co-exposure of bisphenol A (BPA) or bisphenol S (BPS) and 25 μm polyethylene MP. Impacts on their offspring (the F1 generation) were also investigated. The reproductive toxicity in adult zebrafish impacted exerted by bisphenol compounds were aggravated by the co-presence of MP. Transcriptomics and metabolomics further showed single or co-exposure of bisphenol compounds and MP could together regulate apoptosis, calcium signaling pathway and glycerophospholipid signaling pathways. Our results also showed the different toxicity mechanisms on transcriptional and metabolic profiles in the combination effects of bisphenol compounds and MP. The co-exposure of BPA and MP predominantly influenced neurotoxicity via the MAPK signaling pathway and voltage-dependent calcium channels, whereas the co-exposure of BPS and MP principally affected visual development through phototransduction and retinol metabolism. The co-exposure of BPA and MP, as well as BPS and MP, specifically regulate lipid metabolism and carbohydrate metabolism in zebrafish offspring, respectively. Overall, this study provided a deep understanding of the toxicity differences between co-exposure and single exposure of bisphenol compound and MP in zebrafish, as well as the transgenerational effects and potential molecular mechanisms of bisphenol compounds and MP in zebrafish offspring.

Cardiomyocyte Reduction of Hybrid/Complex N-Glycosylation in the Adult Causes Heart Failure With Reduced Ejection Fraction in the Absence of Cellular Remodeling.

Heart failure (HF) presents a massive burden to health care with a complex pathophysiology that results in HF with reduced left ventricle ejection fraction (EF) or HF with preserved EF. It has been shown that relatively modest changes in protein glycosylation, an essential posttranslational modification, are associated with clinical presentations of HF. We and others previously showed that such aberrant protein glycosylation in animal models can lead to HF. We develop and characterize a novel, tamoxifen-inducible, cardiomyocyte Mgat1 knockout mouse strain, achieved through deletion of Mgat1, alpha-1,3-mannosyl-glycoproten 2-beta-N-acetlyglucosaminyltransferase, which encodes N-acetylglucosaminyltransferase I. We investigate the role of hybrid/complex N-glycosylation in adult HFrEF pathogenesis at the ion channel, cardiomyocyte, tissue, and gross cardiac level. The data demonstrate successful reduction of N-acetylglucosaminyltransferase I activity and confirm that hybrid/complex N-glycans modulate gating of cardiomyocyte voltage-gated calcium channels. A longitudinal study shows that the tamoxifen-inducible, cardiomyocyte Mgat1 knockout mice present with significantly reduced systolic function by 28 days post induction that progresses into HFrEF by 8 weeks post induction, without significant ventricular dilation or hypertrophy. Further, there was minimal, if any, physiologic or pathophysiologic cardiomyocyte electromechanical remodeling or fibrosis observed before (10-21 days post induction) or after (90-130 days post induction) HFrEF development. The tamoxifen-inducible, cardiomyocyte Mgat1 knockout mouse strain created and characterized here provides a model to describe novel mechanisms and causes responsible for HFrEF onset in the adult, likely occurring primarily through tissue-level reductions in electromechanical activity in the absence of (or at least before) cardiomyocyte remodeling and fibrosis.

Novel Far-Red Fluorescent 1,4-Dihydropyridines for L-Type Calcium Channel Imaging.

Upregulation of L-type calcium channels (LTCCs) is implicated in a range of cardiovascular and neurological disorders. Therefore, the development of toolboxes that unlock fast imaging protocols in live cells is coveted. Herein, we report a library of first-in-class far-red small-molecule-based fluorescent ligands (FluoDiPines), able to target LTCCs. All fluorescent ligands were evaluated in whole-cell patch-clamp and live-cell Ca2+ imaging whereby FluoDiPine 6 was found to be the best candidate for live-cell fluorescence imaging. Low concentration of FluoDiPine 6 (50 nM) and a quick labeling protocol (5 min) are successfully applied to fixed and live cells to image LTCCs with good specificity.

Telangiectasia Macularis Multiplex Acquisita and its Potential Association with Calcium Channel Blockers: A Retrospective Study of 46 Chinese Patients.

Telangiectasia macularis multiplex acquisita is an acquired cutaneous telangiectasis of unknown aetiology, and it lacks both effective and cost-efficient treatment. This study aims to identify a novel potential associated factor of the disease and explore feasible therapeutic interventions. In this retrospective case series study, 46 Chinese patients diagnosed with telangiectasia macularis multiplex acquisita between 1 January 2007 and 18 May 2023 were included. The median age of onset was 43 years (23 to 60 years), and the male to female ratio was 10.5:1. Besides previously reported associations including chronic liver disorders, alcohol consumption, and smoking, a potential association was found between use of calcium channel blockers and development of telangiectasia macularis multiplex acquisita. Twenty-two of 27 hypertensive patients took calcium channel blockers, with 17 followed up. Ten out of 17 displayed a range of improvements following the cessation of calcium channel blockers; 1 patient reported no lesion change post-discontinuation of calcium channel blockers; 1 patient continued their medication but showed partial improvement after 2 pulsed dye laser treatments; 1 patient observed lesion colour lightening without altering hypertensive medication or other specific treatments; and another 4 kept their previous hypertensive regimen due to blood pressure stability concerns, with no change in their lesions. The study proposes that cessation of calcium channel blockers can be a novel therapeutic approach for affected individuals.

New connections of medication use and polypharmacy with the gut microbiota composition and functional potential in a large population

Medication can affect the gut microbiota composition and function. The aim of this study was to investigate connections between use of common non-antibiotic medicines and the gut microbiota composition and function in a large Swedish cohort (N = 2223). Use of 67 medications and polypharmacy (≥ 5 medications), based on self-reported and prescription registry data, were associated with the relative abundance of 881 gut metagenomic species (> 5% prevalence) and 103 gut metabolic modules (GMMs). Altogether, 97 associations of 26 medications with 40 species and of four medications with five GMMs were observed (false discovery rate < 5%). Several earlier findings were replicated like the positive associations of proton pump inhibitors (PPIs) with numerous oral species, and those of metformin with Escherichia species and with lactate consumption I and arginine degradation II. Several new associations were observed between, among others, use of antidepressants, beta-blockers, nonsteroidal anti-inflammatory drugs and calcium channel blockers, and specific species. Polypharmacy was positively associated with Enterococcus faecalis, Bacteroides uniformis, Rothia mucilaginosa, Escherichia coli and Limosilactobacillus vaginalis, and with 13 GMMs. We confirmed several previous findings and identified numerous new associations between use of medications/polypharmacy and the gut microbiota composition and functional potential. Further studies are needed to confirm the new findings.

Co-based carbon material as CYP3A4-like nanozyme with both biocatalytic activity and inhibition behaviors

Up to now, the biocatalytic activity of nanozymes has been extensively studied, while little research focus on their inhibitory behaviors. Here, Co-based carbon material (Co-DMOF) containing abundant carboxylic acid groups was prepared, with defects introduced by COx escape during pyrolysis to achieve controllable activity. As a result, Co-DMOF exhibited biocatalytic activity similar to cytochrome P450 3A4 (CYP3A4) in the metabolism of 1,4-Dihydropyridine (1,4-DHP, a calcium channel blocker). Excitingly, studies on IC50 and drug-drug interaction (DDI) suggested that Co-DMOF had similar inhibitory behaviors to CYP3A4. Moreover, Co-DMOF displayed excellent stability even under high temperature (100 °C), organic solvents, and a wide range of pH (4–9). Additionally, it can be reused for at least 7 times with only slight loss of activity. Therefore, Co-DMOF has great potential to become a low-cost alternative to CYP3A4 for drug dosage guideline, drug metabolism and DDI. This work provides more possibilities for expanding the CYP3A4-like nanozyme library.

Humulus lupulus L.: Evaluation of Phytochemical Profile and Activation of Bitter Taste Receptors to Regulate Appetite and Satiety in Intestinal Secretin Tumor Cell Line (STC-1 Cells).

Inflorescences of the female hop plant (Humulus lupulus L.) contain biologically active compounds, most of which have a bitter taste. Given the rising global obesity rates, there is much increasing interest in bitter taste receptors (TAS2Rs). Intestinal TAS2Rs can have beneficial effects on obesity when activated by bitter agonists. This study aims to investigate the mechanism of action of a hydroalcoholic hop extract in promoting hormone secretion that reduces the sense of hunger at the intestinal level through the interaction with TAS2Rs. The results demonstrate that the hop extract is a rich source of bitter compounds (mainly α-, β-acids) that stimulate the secretion of anorexigenic peptides (glucagon-like peptide 1 [GLP-1], cholecystokinin [CCK]) in a calcium-dependent manner while reducing levels of hunger-related hormones like ghrelin. This effect is mediated through interaction with TAS2Rs, particularly Tas2r138 and Tas2r120, and through the activation of downstream signaling cascades. Knockdown of these receptors using siRNA transfection and inhibition of Trpm5, Plcβ-2, and other calcium channels significantly reduces the hop-induced calcium response as well as GLP-1 and CCK secretion. This study provides a potential application of H. lupulus extract for the formulation of food supplements with satiating activity capable of preventing or combating obesity.

Investigation of local stimulation effects of embedding PGLA at Zusanli (ST36) acupoint in rats based on TRPV2 and TRPV4 ion channels.

Acupoint Catgut Embedding (ACE) is an extended and developed form of traditional acupuncture that serves as a composite stimulation therapy for various diseases. However, its local stimulation effects on acupoints remain unclear. Acupuncture can activate mechanically sensitive calcium ion channels, TRPV2 and TRPV4, located on various cell membranes, promoting Ca2+ influx in acupoint tissues to exert effects. Whether ACE can form mechanical physical stimulation to regulate these channels and the related linkage effect requires validation. This study investigates the influence of TRPV2 and TRPV4 ion channels on the local stimulation effects of ACE by embedding PGLA suture at the Zusanli (ST36) acupoint in rats and using TRPV2 and TRPV4 inhibitors. Flow cytometry, immunofluorescence, Western blot, and Real-time quantitative PCR were employed to detect intracellular Ca2+ fluorescence intensity, the expression of macrophage (Mac) CD68 and mast cell (MC) tryptase, as well as the protein and mRNA expression of TRPV2 and TRPV4 in acupoint tissues after PGLA embedding. The results indicate that ACE using PGLA suture significantly increases the mRNA and protein expression of TRPV2 and TRPV4, Ca2+ fluorescence intensity, and the expression of Mac CD68 and MC tryptase in acupoint tissues, with these effects diminishing over time. The increasing trends are reduced after using inhibitors, particularly when both inhibitors are used simultaneously. Furthermore, correlation analysis shows that embedding PGLA suture at the ST36 acupoint regulates Mac and MC functions through Ca2+ signaling involving not only TRPV2 and TRPV4 but multiple pathways. These results suggest that embedding PGLA suture at the ST36 acupoint generates mechanical physical stimulation and regulates TRPV2 and TRPV4 ion channels, which couple with Ca2+ signaling to form a linkage effect that gradually weakens over time. This provides new reference data for further studies on the stimulation effects and clinical promotion of ACE.

Formulation of Felodipine lipid nanoparticle-loaded oral fast-dissolving films

Abstract Felodipine, a calcium channel blocker used to treat hypertension, is a BCS Class II drug characterized by low solubility, high permeability and significant hepatic metabolism, which limits its bioavailability to 15 %. This study focuses on improving the bioavailability of Felodipine by developing oral fast-dissolving films (OFDFs) incorporating lipid nanoparticles. Felodipine loaded lipid nanoparticles were prepared using glyceryl monooleate (GMO) as lipid and Poloxamer 407 as the surfactant, and then incorporated into OFDFs using the solvent casting technique. A Box-Behnken design with Design Expert Stat-Ease® 360 was used to evaluate the impact of GMO, Poloxamer 407 concentration, and sonication time on particle size and entrapment efficiency. The resulting nanoparticle dispersions had particle sizes ranging from 74.92 nm to 112.1 nm and entrapment efficiencies between 80.43 % and 95.23 %. Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) confirmed successful drug encapsulation. The OFDF showed optimal mechanical properties, disintegration within (41.33 ± 3.51) s, and an in-vitro drug release of (89.82 ± 2.75) % in 6 min. Scanning electron microscopy (SEM) revealed a smooth, uniform, porous surface and the films remained stable for three months. The study concludes that Felodipine loaded lipid nanoparticles in fast-dissolving OFDFs improve permeability, dissolution, and onset of action, making them a promising approach for antihypertensive therapy.

Multidrug Resistance Reversed by Maleimide Interactions. A Biological and Synthetic Overview for an Emerging Field.

Multidrug Resistance (MDR) can be considered one of the most frightening adaptation types in bacteria, fungi, protozoa, and eukaryotic cells. It allows the organisms to survive the attack of many drugs used in the daily basis. This force the development of new and more complex, highly specific drugs to fight diseases. Given the high usage of medicaments, poor variation in active chemical cores, and self-medication, the appearance of MDR is more frequent each time, and has been established as a serious medical and social problem. Over the years it has been possible the identification of several genes and proteins responsible for MDR and with that the development of blockers of them to reach MDR reversion and try to avoid a global problem. These mechanisms also have been observed in cancer cells, and several calcium channel blockers have been successful in MDR reversion, and the maleimide can be found included in them. In this review we explore the history, mechanisms, reversion efforts, and we specifically focused on the maleimide synthesis as MDR-reversers in co-administration, as well as their biological applications in a urge to expand the available information and explore a very plausible MDR reversion source.

Calcium Channels, Clustering, and Single-Amino Acid Control of Blood Pressure and Blood Flow.

Calcium Channels, Clustering, and Single-Amino Acid Control of Blood Pressure and Blood Flow.

Thyroid Hormone Upregulates Cav1.2 Channels in Cardiac Cells via the Downregulation of the Channels' β4 Subunit.

Thyroid hormone binds to specific nuclear receptors, regulating the expression of target genes, with major effects on cardiac function. Triiodothyronine (T3) increases the expression of key proteins related to calcium homeostasis, such as the sarcoplasmic reticulum calcium ATPase pump, but the detailed mechanism of gene regulation by T3 in cardiac voltage-gated calcium (Cav1.2) channels remains incompletely explored. Furthermore, the effects of T3 on Cav1.2 auxiliary subunits have not been investigated. We conducted quantitative reverse transcriptase polymerase chain reaction, Western blot, and immunofluorescence experiments in H9c2 cells derived from rat ventricular tissue, examining the effects of T3 on the expression of α1c, the principal subunit of Cav1.2 channels, and Cavβ4, an auxiliary Cav1.2 subunit that regulates gene expression. The translocation of phosphorylated cyclic adenosine monophosphate response element-binding protein (pCREB) by T3 was also examined. We found that T3 has opposite effects on these channel proteins, upregulating α1c and downregulating Cavβ4, and that it increases the nuclear translocation of pCREB while decreasing the translocation of Cavβ4. Finally, we found that overexpression of Cavβ4 represses the mRNA expression of α1c, suggesting that T3 upregulates the expression of the α1c subunit in response to a decrease in Cavβ4 subunit expression.