Calcium channel blockers potentiate gemcitabine chemotherapy in pancreatic cancer.

There is currently no effective treatment for pancreatic ductal adenocarcinoma (PDAC). While palliative chemotherapy offers a survival benefit to most patients, nearly all will eventually progress on treatment and long-term survivability remains poor. Given the lack of subsequent line treatment options, in this study, we sought to identify novel strategies to prevent, delay, or overcome resistance to gemcitabine, one of the most widely used medications in PDAC. Using a combination of single-cell RNA sequencing and high-throughput proteomic analysis, we identified a subset of gemcitabine-resistant tumor cells enriched for calcium/calmodulin signaling. Pharmacologic inhibition of calcium-dependent calmodulin activation led to the rapid loss of drug-resistant phenotypes in vitro, which additional single-cell RNA sequencing identified was due to impaired activation of the RAS/ERK signaling pathway. Consistent with these observations, calcium chelation or depletion of calcium in the culture media also impaired ERK activation in gemcitabine-resistant cells, and restored therapeutic responses to gemcitabine in vitro. We observed similar results using calcium channel blockers (CCBs) such as amlodipine, which inhibited prosurvival ERK signaling in vitro and markedly enhanced therapeutic responses to gemcitabine in both orthotopic xenografts and transgenic models of PDAC. Combined, these results offer insight into a potential means of gemcitabine resistance and suggest that select CCBs may provide a clinical benefit to PDAC patients receiving gemcitabine-based chemotherapy.

Amlodipine inhibits Synaptotagmin-4's oncogenic activity on gastric cancer proliferation by targeting calcium signaling.

BACKGROUND: Gastric cancer (GC) remains a leading cause of cancer mortality globally. Synaptotagmin-4 (SYT4), a calcium-sensing synaptic vesicle protein, has been implicated in the oncogenesis of diverse malignancies. PURPOSE: This study delineates the role of SYT4 in modulating clinical outcomes and biological behaviors in GC. METHODS: We evaluated SYT4 expression in GC specimens using bioinformatics analyses and immunohistochemistry. Functional assays included CCK8 proliferation tests, apoptosis assays via flow cytometry, confocal calcium imaging, and xenograft models. Western blotting elucidated MAPK pathway involvement. Additionally, we investigated the impact of the calcium channel blocker amlodipine on cellular dynamics and MAPK pathway activity. RESULTS: SYT4 was higher in GC tissues, and the elevated SYT4 was significantly correlated with adverse prognosis. Both univariate and multivariate analyses confirmed SYT4 as an independent prognostic indicator for GC. Functionally, SYT4 promoted tumorigenesis by fostering cellular proliferation, inhibiting apoptosis, and enhancing intracellular Ca2+ influx, predominantly via MAPK pathway activation. Amlodipine pre-treatment attenuated SYT4-driven cell growth and potentiated apoptosis, corroborated by in vivo xenograft assessments. These effects were attributed to MAPK pathway suppression by amlodipine. CONCLUSION: SYT4 emerges as a potential prognostic biomarker and a pro-oncogenic mediator in GC through a Ca2+-dependent MAPK mechanism. Amlodipine demonstrates significant antitumor effects against SYT4-driven GC, positing its therapeutic promise. This study underscores the imperative of targeting calcium signaling in GC treatment strategies.

Gene Polymorphisms and Drug-Drug Interactions Determine the Metabolic Profile of Blonanserin.

This study aimed to evaluate the effects of cytochrome P450 3A4 (CYP3A4) gene polymorphism and drug interaction on the metabolism of blonanserin. Human recombinant CYP3A4 was prepared using the Bac-to-Bac baculovirus expression system. A microsomal enzyme reaction system was established, and drug-drug interactions were evaluated using Sprague-Dawley rats. Ultra-performance liquid chromatography-tandem mass spectrometry was used to detect the concentrations of blonanserin and its metabolite. Compared with wild type CYP34A, the relative clearance of blonanserin by CYP3A4.29 significantly increased to 251.3%, while it decreased notably with CYP3A4.4, 5, 7, 8, 9, 10, 12, 13, 14, 16, 17, 18, 23, 24, 28, 31, 33, and 34, ranging from 6.09% to 63.34%. Among 153 tested drugs, nimodipine, felodipine, and amlodipine were found to potently inhibit the metabolism of blonanserin. Moreover, the inhibitory potency of nimodipine, felodipine, and amlodipine varied with different CYP3A4 variants. The half-maximal inhibitory concentration and enzymatic kinetics assay demonstrated that the metabolism of blonanserin was noncompetitively inhibited by nimodipine in rat liver microsomes and was inhibited in a mixed manner by felodipine and amlodipine in both rat liver microsomes and human liver microsomes. When nimodipine and felodipine were coadministered with blonanserin, the area under the blood concentration-time curve (AUC)(0-t), AUC(0-∞), and C max of blonanserin increased. When amlodipine and blonanserin were combined, the C max of blonanserin C increased remarkably. The vast majority of CYP3A4 variants have a low ability to catalyze blonanserin. With combined administration of nimodipine, felodipine, and amlodipine, the elimination of blonanserin was inhibited. This study provides the basis for individualized clinical use of blonanserin. SIGNIFICANCE STATEMENT: The enzyme kinetics of novel CYP3A4 enzymes for metabolizing blonanserin were investigated. Clearance of blonanserin by CYP3A4.4, 5, 7-10, 12-14, 16-18, 23-24, 28, 31, 33, and 34 decreased notably, but increased with CYP3A4.29. Additionally, we established a drug interaction spectrum for blonanserin, in which nimodipine, felodipine, and amlodipine kinetics exhibited mixed inhibition. Moreover, their inhibitory potencies decreased with CYP3A4.4 and 5 compared to CYP3A4.1. This study provides essential data for personalized clinical use of blonanserin.

Anti-atrial Fibrillatory and Cardiorenal Protective Effects of the Combination of Valsartan and Cilnidipine in Dahl Salt-Sensitive Rats.

The current study aimed to investigate the anti-atrial fibrillatory (AF) effects of a combination of valsartan and a calcium channel blocker (cilnidipine or amlodipine) in Dahl salt-sensitive (Dahl S) rats. Seven-week-old male Dahl S rats were fed an 8% salt diet. Six weeks later, valsartan (60 mg/kg, Val group), cilnidipine + valsartan (10 + 60 mg/kg, CV group), amlodipine + valsartan (3 + 60 mg/kg, AV group), or vehicle was orally administered daily for 5 weeks. Echocardiography and atrial electrophysiological evaluations were performed on the last day of treatment. Blood pressure in each drug treatment group was lower than in the Vehicle group. The duration of AF induced by atrial burst stimulation was shorter in the Val group (3.2 ± 1.6 s) than in the Vehicle group (11.2 ± 6.0 s), which was further shortened in the CV and AV groups (1.1 ± 0.3 and 1.3 ± 0.3 s, respectively). Left ventricular ejection fraction and left ventricular fractional shortening were greater in the CV and AV groups than those in the Vehicle group. Urinary albumin excretion in the CV group was the lowest among the drug-treated groups. The results collectively suggest that the combination of a calcium channel blocker with valsartan could be useful in terms of its anti-AF action as well as for improving cardiac and renal functions.

Synergistic combination of carvedilol, amlodipine, amitriptyline, and antibiotics as an alternative treatment approach for the susceptible and multidrug-resistant A. baumannii infections via drug repurposing.

We evaluated in vitro activity of 13 drugs used in the treatment of some non-communicable diseases via repurposing to determine their potential use in the treatment of Acinetobacter baumannii infections caused by susceptible and multidrug-resistant strains. A. baumannii is a multidrug-resistant Gram-negative bacteria causing nosocomial infections, especially in intensive care units. It has been identified in the WHO critical pathogen list and this emphasises urgent need for new treatment options. As the development of new therapeutics is expensive and time consuming, finding new uses of existing drugs via drug repositioning has been favoured. Antimicrobial susceptibility tests were conducted on all 13 drugs according to CLSI. Drugs with MIC values below 128 µg/mL and control antibiotics were further subjected to synergetic effect and bacterial time-kill analysis. Carvedilol-gentamicin (FICI 0.2813) and carvedilol-amlodipine (FICI 0.5625) were determined to have synergetic and additive effect, respectively, on the susceptible A. baumannii strain, and amlodipine-tetracycline (FICI 0.75) and amitriptyline-tetracycline (FICI 0.75) to have additive effect on the multidrug-resistant A. baumannii strain. Most remarkably, both amlodipine and amitriptyline reduced the MIC of multidrug-resistant, including some carbapenems, A. baumannii reference antibiotic tetracycline from 2 to 0.5 µg/mL, for 4-folds. All these results were further supported by bacterial time-kill assay and all combinations showed bactericidal activity, at certain hours, at 4XMIC. Combinations proposed in this study may provide treatment options for both susceptible and multidrug-resistant A. baumannii infections but requires further pharmacokinetics and pharmacodynamics analyses and in vivo re-evaluations using appropriate models.

Effects of olmesartan and amlodipine on blood pressure, endothelial function, and vascular inflammation.

BACKGROUND: Anti-hypertensive drugs can improve vascular endothelial function. However, the mechanism remains to be elucidated. OBJECTIVES: This study sought to investigate mechanisms of anti-hypertensive drugs on improvement of vascular endothelial function in patients with essential hypertension. METHODS: Forty-five patients (mean age 58.5 ± 11.2 years) with uncontrolled essential hypertension were randomly assigned to receive olmesartan, an angiotensin II type 1 receptor blocker (ARB) (N = 23), or amlodipine, a calcium channel blocker (CCB) (N = 22), for 6 months. Endothelial function was evaluated by flow-mediated dilatation (FMD) of the brachial artery. Vascular inflammation was measured by blood-normalized standardized uptake value, known as a target-to-background ratio (TBR) within the carotid arteries using 18F-fluorodeoxyglucose-positron emission tomography combined with computed tomography. RESULTS: There were no significant differences of baseline clinical data between the ARB and CCB groups. Both anti-hypertensive drugs comparably lowered blood pressure and increased %FMD. TBR values were reduced by olmesartan (P < .001), while blood pressure variability was decreased by amlodipine (P = .004). Changes in %FMD from baseline (Δ%FMD) were inversely associated with ΔTBR in the olmesartan group (r = - .606, P = .003) and with Δsystolic blood pressure variability in the amlodipine group (r = - .434, P = .039). CONCLUSION: Our study indicated that olmesartan and amlodipine could improve endothelial function in patients with essential hypertension in different manners, suppression of vascular inflammation, and decrease in blood pressure variability, respectively.

Enzymatic synthesis of amlodipine amides and evaluation of their anti-Trypanosoma cruzi activity.

Advancing with our project about the development of new antiparasitic agents, we have enzymatically synthesized a series of amides derived from amlodipine, a calcium channel blocker used as an antihypertensive drug. Through lipase-catalyzed acylation with different carboxylic acids, nineteen amlodipine derivatives were obtained, eighteen of which were new compounds. To optimize the reaction conditions, the influence of several reaction parameters was analyzed, finding different requisites for aliphatic carboxylic acids and phenylacetic acids. All synthesized compounds were evaluated as antiproliferative agents against Trypanosoma cruzi, the etiological agent of American trypanosomiasis (Chagas' disease). Some of them showed significant activity against the amastigote form of T. cruzi, the clinically relevant form of the parasite. Among synthesized compounds, the derivatives of myristic and linolenic acids showed higher efficacy and lower cytotoxicity. These results added to the advantages shown by the enzymatic methodology, such as mild reaction conditions and low environmental impact, making this approach a valuable way to synthesize these amlodipine derivatives with an application as promising antiparasitic agents.

Effects of Aliskiren Monotherapy versus Amlodipine Monotherapy in Hypertensive Patients with Obesity or Type 2 Diabetes Mellitus.

INTRODUCTION: Renin-angiotensin system inhibitors have been reported to exert protective effects against organ damage and failure; however, the impact of the direct renin inhibitor as monotherapy has not been assessed. Here, we investigated the effects of 24-week monotherapy with aliskiren compared to amlodipine in hypertensive patients with type 2 diabetes or obesity. METHODS: In this randomized intervention study, 62 adult hypertensive patients with visceral obesity (defined as a body mass index [BMI] greater than 25 kg/m2 and a visceral adipose tissue area [VFA] greater than 100 cm2) or type 2 diabetes mellitus (age 57 ± 13, 65% men, BMI 28.8 ± 4.8 kg/m2, VFA 134.8 ± 47.0 cm2, blood pressure 141 ± 16/86 ± 13 mm Hg) were randomized to receive 24-week treatment with aliskiren (max. 300 mg) or amlodipine (max. 10 mg). The primary outcome was the change in VFA at 24 weeks post-treatment. RESULTS: Change in VFA did not differ significantly from baseline in either group. Systolic blood pressure significantly decreased at 12 weeks (-10 mm Hg, p = 0.001) and 24 weeks (-10 mm Hg, p = 0.001) in the amlodipine group and at 24 weeks (-11 mm Hg, p = 0.001) in the aliskiren group. Diastolic blood pressure significantly decreased at 24 weeks (-6 mm Hg, p = 0.009) only in the amlodipine group. Although the estimated glomerular filtration rates did not significantly change in either group, the logarithm of urinary albumin excretion significantly decreased at 24 weeks only in the aliskiren group (-0.60, p < 0.001). The 24-week changes in the urinary albumin excretion significantly correlated with the changes in the plasma renin activity in the aliskiren group (r = 0.51, p = 0.008). CONCLUSION: Aliskiren monotherapy did not show any superiority to amlodipine monotherapy on VFA, estimated glomerular filtration rates, or urinary albumin excretion in obese or type 2 diabetic hypertensive patients.

Folic acid enhances the cardiovascular protective effect of amlodipine in renal hypertensive rats with elevated homocysteine.

OBJECTIVES: To investigate the actions of amlodipine-folic acid (amlodipine-FA) preparation on hypertension and cardiovascular in renal hypertensive rats with hyperhomocysteinemia (HHcy), so as to provide experimental basis for clinical research of amlodipine folic acid tablets. METHODS: Rats model of renal hypertension with HHcy were established. The rats were randomly divided into groups of model, amlodipine, folic acid (FA) and amlodipine-FA of various dosages. Normal rats were used as normal control group. Blood pressure, Hcy as well as plasma NO, ET-1 and hemodynamics were assayed. Histological alterations of heart and abdominal aorta were also examined. RESULTS: Compared with the normal group, blood pressure, plasma Hcy, and NO of the rats in model group were significantly increased, while the plasma ET-1 was decreased. Compared with the normal group, the animals in the model group had reduced cardiac function, thickened wall of the aorta and narrowed lumen. In FA group and amlodipine group, the rat plasma NO was increased while ET-1 was decreased, the protective effect of amlodipine-FA group on endothelial cells was further enhanced. In amlodipine group, the rat hemodynamics (LVSP, LVEDP and ±dp/dtmax, et al.) and vascular damage were significantly reduced, while in amlodipine-FA group, the heart function were further improved, and myocardial and vascular hypertrophy were significantly reduced. CONCLUSIONS: As compared to amlodipine alone, amlodipine -FA can lower both blood pressure and plasma Hcy, significantly enhancing vascular endothelial function to protect the heart and blood vessel in renal hypertensive rats with HHcy.

In hypertension, a quadpill containing quarter doses of 4 BP drugs reduced BP at 12 wk vs. standard-dose monotherapy.

SOURCE CITATION: Chow CK, Atkins ER, Hillis GS, et al. Initial treatment with a single pill containing quadruple combination of quarter doses of blood pressure medicines versus standard dose monotherapy in patients with hypertension (QUARTET): a phase 3, randomised, double-blind, active-controlled trial. Lancet. 2021;398:1043-52. 34469767.

Effects of Valsartan and Amlodipine Tablets Combined with α-Lipoic Acid on T-AOC, IL-6 and ß2-MG Levels in Patients with Diabetic Nephropathy.

Diabetic nephropathy (DN) is the most important cause of chronic renal and end-stage kidney disease in China. Hypertension (HTN) is highly prevalent in individuals with diabetic nephropathy. Arterial HTN affects two-thirds of people with type 2 diabetes (T2D). In these patients, HTN increased the potential of both micro- and macrovascular complications, and the co-occurrence of 2 such principal causes results in a 4-fold increased risk for cardiovascular disease (CVD) when contrasted with normotensive controls without diabetes. Therefore, the results of valsartan and amlodipine tablets combined with alpha-lipoic acid on total antioxidant capacity (T-AOC) need to be investigated. The aim of this study was to analyze the effects of valsartan (VA) and amlodipine tablets combined with alpha-lipoic acid (α-LA) on T-AOC, IL-6 and ß2-MG levels in patients with DN. We performed statistical analysis including the chi-square test, independent t-test, paired t-test and Analysis of Variance (ANOVA). Our findings indicate that VA, amlodipine and α-LA has a significant effect in patients with DN.

Comparison of antihypertensive drugs amlodipine and perindopril on blood pressure variability after long-term treatment of hypertension induced by apatinib and bevacizumab.

The purpose of this study was to elucidate the therapeutic effect of different antihypertensive drugs (amlodipine and perindopril) on hypertension induced by apatinib and bevacizumab. Sixty patients with hypertension treated with apatinib or bevacizumab were selected and divided into two groups: one group was treated with amlodipine and the other group was treated with perindopril. Before and after treatment, the dynamic blood pressure (BP) measurement (systolic BP [SBP] and diastolic BP [DBP]), echocardiography (left ventricular end-diastolic diameter, interventricular septal thickness [IVST], left ventricular posterior wall thickness [LVPWT], and left atrial diameter [LAD]), and detection of nitric oxide (NO) content in venous blood were performed. In the amlodipine group, the 24hSBP, 24hSSD, 24hSCV, daytime mean SBP (dSBP), daytime mean SSD (dSSD), daytime mean SBP CV, night mean SBP (nSBP), night mean SSD, 24hDBP, 24hDSD, 24 h DBP CV, daytime mean DBP (dDBP), daytime mean DSD (dDSD), daytime mean DBP CV, night mean DBP (nDBP), LAD, and LAD index (LADi) after treatment were all lower than before treatment, while NO was higher than before treatment (all P < 0.05). In the perindopril group, the 24hSBP, dSBP, nSBP, 24hDBP, dDBP, nDBP, LAD, LADi, IVST, LVPWT, and left ventricular mass index (LVMI) after treatment were lower than before treatment, and NO level after treatment was higher than before treatment (all P < 0.05). After treatment, the 24hSBP, 24hSSD, dSBP, dSSD, nSBP, 24hDBP, 24hDSD, dDBP, dDSD, nDBP, night mean DSD, and NO were all lower while the LAD, LADi, IVST, LVPWT, and LVMI were higher in the amlodipine group than those in the perindopril group (all P < 0.05). Our study suggests that the SBP and DBP variability of amlodipine in the treatment of hypertension induced by apatinib and bevacizumab is slightly better than that of perindopril, but the effect of perindopril in improving endothelial function indices NO and echocardiographic data is better than that of amlodipine.

Effects of 5-fluorouracil Co-administration on Blood Pressure in Patients Maintained on Antihypertensives: a Retrospective Case Series.

This study aimed to investigate the possible drug-drug interactions (DDIs) of 5-FU with antihypertensives metabolised by CYP3A4 and 2C9, using blood pressure (BP) as a pharmacodynamic (PD) parameter. Patients who received 5-FU in combination with antihypertensives metabolised by CYP3A4 or 2C9, specifically, a) amlodipine, nifedipine, or amlodipine + nifedipine, b) candesartan or valsartan, or c) amlodipine + candesartan, amlodipine + losartan, or nifedipine + valsartan, (Group A, n = 20) were identified. Patients who received 5-FU with WF and antihypertensives, specifically, a) amlodipine or b) amlodipine + telmisartan, amlodipine + candesartan, or amlodipine + valsartan, (Group B, n = 5) or 5-FU alone (Group C, n = 25) were also identified and analysed as a comparator and control group, respectively. Regarding the peak BP levels during chemotherapy, there was a significant increase in both SBP (P < 0.0002 and 0.0013) and DBP (P = 0.0243 and 0.0032) in Groups A and C, respectively (Tukey-Kramer test). In contrast, although SBP also increased in Group B during chemotherapy, the change was not statistically significant and there was a decrease in DBP. The significant increase in SBP can be attributed to chemotherapy-induced hypertension by 5-FU or other drugs in the chemotherapeutic regimens. However, when comparing the lowest BP levels during chemotherapy, there was a decrease in SBP and DBP in all groups from the baseline values. The median time to peak and lowest BP was at least 2 weeks and 3 weeks, respectively, for all groups, suggesting that a BP lowering effect was observed following the offset of the initial chemotherapy-induced hypertension. At least 1 month after 5-FU chemotherapy, the SBP and DBP returned to baseline values in all groups. Since Group B also showed a significant increase in PT-INR, possibly demonstrating 5-FU inhibition of CYP activity and, consequently, of WF metabolism, it is likely that 5-FU also inhibited the metabolism of the antihypertensive drugs. The findings suggest possible DDIs between 5-FU and antihypertensives metabolised by CYP3A4.

Pitavastatin and Lovastatin Exhibit Calcium Channel Blocking Activity Which Potentiate Vasorelaxant Effects of Amlodipine: A New Futuristic Dimension in Statin's Pleiotropy.

Background and Objectives: We have recently reported that Fluvastatin, Atorvastatin, Simvastatin and Rosuvastatin have calcium channel antagonistic activities using rabbits' intestinal preparations. The current study is focused on the effects of Pitavastatin and Lovastatin for possible inhibition of vascular L-Type calcium channels, which may have vasorelaxant effect(s). Combined effects of Pitavastatin and Lovastatin in the presence of Amlodipine were also tested for vasorelaxation. Materials and Methods: Possible relaxing effects of Pitavastatin and Lovastatin on 80 mM Potassium chloride (KCL)-induced contractions and on 1 µM norepinephrine (N.E)-induced contractions were studied in isolated rabbit's aortic strips preparations. Relaxing effects on 80 mM KCL-induced vascular contractions were further verified by constructing Calcium Concentration Response Curves (CCRCs), in the absence and presence of three different concentrations of Pitavastatin and Lovastatin using CCRCs as negative control. Verapamil was used as a standard drug that has L-Type calcium channel binding activity. In other series of experiments, we studied drug interaction(s) among Pitavastatin, Lovastatin, and amlodipine. Results: The results of this study imply that Lovastatin is more potent than Pitavastatin for having comparatively lower EC50 (7.44 × 10-5 ± 0.16 M) in intact and (4.55 × 10-5 ± 0.10 M) in denuded aortae for KCL-induced contractions. Lovastatin amplitudes in intact and denuded aortae for KCL-induced contractions were, respectively, 24% and 35.5%; whereas amplitudes for Pitavastatin in intact and denuded aortae for KCL-induced contractions were 34% and 40%, respectively. A left shift in the EC50 values for the statins was seen when we added amlodipine in EC50 (Log Ca++ M). Right shift for CCRCs state that Pitavastatin and Lovastatin have calcium channel antagonistic effects. Lovastatin in test concentration (6.74 × 10-7 M) produced a right shift in relatively lower EC50 (-2.5 ± 0.10) Log Ca++ M as compared to Pitavastatin, which further confirms that lovastatin is relatively more potent. The right shift in EC50 resembles the right shift of Verapamil. Additive effect of Pitavastatin and Lovastatin was noted in presence of amlodipine (p < 0.05). Conclusions: KCL (80 mM)-induced vascular contractions were relaxed by Pitavastatin and Lovastatin via inhibitory effects on L-Type voltage-gated calcium channels. Lovastatin and Pitavastatin also relaxed Norepinephrine (1 µM)-induced contractions giving an insight for involvement of dual mode of action of Pitavastatin and Lovastatin.

Atorvastatin and Fluvastatin Potentiate Blood Pressure Lowering Effect of Amlodipine through Vasorelaxant Phenomenon.

Background and Objectives: We have recently reported that stains have calcium channel blocking activity in isolated jejunal preparations. In this study, we examined the effects of atorvastatin and fluvastatin on blood vessels for a possible vasorelaxant effect. We also studied the possible additional vasorelaxant effect of atorvastatin and fluvastatin, in the presence of amlodipine, to quantify its effects on the systolic blood pressure of experimental animals. Materials and Methods: Atorvastatin and fluvastatin were tested in isolated rabbits' aortic strip preparations using 80mM Potassium Chloride (KCl) induced contractions and 1 micro molar Norepinephrine (NE) induced contractions. A positive relaxing effect on 80 mM KCl induced contractions were further confirmed in the absence and presence of atorvastatin and fluvastatin by constructing calcium concentration response curves (CCRCs) while using verapamil as a standard calcium channel blocker. In another series of experiments, hypertension was induced in Wistar rats and different test concentrations of atorvastatin and fluvastatin were administered in their respective EC50 values to the test animals. A fall in their systolic blood pressure was noted using amlodipine as a standard vasorelaxant drug. Results: The results show that fluvastatin is more potent than amlodipine as it relaxed NE induced contractions where the amplitude reached 10% of its control in denuded aortae. Atorvastatin relaxed KCL induced contractions with an amplitude reaching 34.4% of control response as compared to the amlodipine response, i.e., 39.1%. A right shift in the EC50 (Log Ca++ M) of Calcium Concentration Response Curves (CCRCs) implies that statins have calcium channel blocking activity. A right shift in the EC50 of fluvastatin with relatively less EC50 value (-2.8 Log Ca++ M) in the presence of test concentration (1.2 × 10-7 M) of fluvastatin implies that fluvastatin is more potent than atorvastatin. The shift in EC50 resembles the shift of Verapamil, a standard calcium channel blocker (-1.41 Log Ca++ M). Conclusions: Atorvastatin and fluvastatin relax the aortic strip preparations predominantly through the inhibition of voltage gated calcium channels in high molar KCL induced contractions. These statins also inhibit the effects of NE induced contractions. The study also confirms that atorvastatin and fluvastatin potentiate blood pressure lowering effects in hypertensive rats.

S-AMLODIPINE AS A MODERN EFFECTIVE ANTIHYPERTENSIVE AND AN ANTIANGINAL AGENT.

OBJECTIVE: The aim: Study of the clinical and hemodynamic effects of S-amlodipine in patients with arterial hypertension associated with coronary artery disease, in individuals with preserved LV systolic function. PATIENTS AND METHODS: Materials and methods: The study includes 51 patients with arterial hypertension associated with coronary artery disease, who were treated with S-amlodipine. RESULTS: Results: This study shows the high clinical effectiveness of the use of S-amlodipine in patients with arterial hypertension associated with coronary artery disease. We reveal that treatment of hypertensive patients with coronary artery disease with S-amlodipine leads to improvement of LV diastolic dysfunction, bringing it closer to normal values. CONCLUSION: Conclusions: Clinical effectiveness was associated with positive changes in hemodynamics, and was expressed in the normalization of the left ventricle diastolic function parameters, about which indirectly indicates decreasing of end-diastolic pressure.

Rosuvastatin and Simvastatin potentiate antihypertensive effect of amlodipine through vasorelaxation phenomenon.

This study is carried out to assess the effects of rosuvastatin and simvastatin on blood vessels for possible vasorelaxant effect. The study is also translating the possible vasorelaxant effect in Wistar rats for a subsequent fall in systolic blood pressure. It is evident from the EC50, that rosuvastatin is more effective on relaxing N.E induced contractions, while simvastatin is more effective on relaxing KCL induced contractions. Simvastatin is equipotent when compared to effects of amlodipine on KCl induced contractions in denuded aortae. Simvastatin produced significant right shift in test concentration 1.1× 10-6M with its respective EC50 -1.85logCa++M as compared to its respective control EC50 -3logCa++M. Rosuvastatin also produced significant right shift in the EC50. In conclusion, it is stated that rosuvastatin and simvastatin relax the aortic strips preparations through inhibition of voltage gated calcium channels and inhibition of N.E induced contractions. Rosuvastatin and simvastatin have additive effects when used in the presence of a standard vaso-relaxant drug like amlodipine, which further confirms its additive effect on decreasing the systolic blood pressure of hypertensive rats (P<0.05).

Structural basis for inhibition of a voltage-gated Ca2+ channel by Ca2+ antagonist drugs.

Ca2+ antagonist drugs are widely used in therapy of cardiovascular disorders. Three chemical classes of drugs bind to three separate, but allosterically interacting, receptor sites on CaV1.2 channels, the most prominent voltage-gated Ca2+ (CaV) channel type in myocytes in cardiac and vascular smooth muscle. The 1,4-dihydropyridines are used primarily for treatment of hypertension and angina pectoris and are thought to act as allosteric modulators of voltage-dependent Ca2+ channel activation, whereas phenylalkylamines and benzothiazepines are used primarily for treatment of cardiac arrhythmias and are thought to physically block the pore. The structural basis for the different binding, action, and therapeutic uses of these drugs remains unknown. Here we present crystallographic and functional analyses of drug binding to the bacterial homotetrameric model CaV channel CaVAb, which is inhibited by dihydropyridines and phenylalkylamines with nanomolar affinity in a state-dependent manner. The binding site for amlodipine and other dihydropyridines is located on the external, lipid-facing surface of the pore module, positioned at the interface of two subunits. Dihydropyridine binding allosterically induces an asymmetric conformation of the selectivity filter, in which partially dehydrated Ca2+ interacts directly with one subunit and blocks the pore. In contrast, the phenylalkylamine Br-verapamil binds in the central cavity of the pore on the intracellular side of the selectivity filter, physically blocking the ion-conducting pathway. Structure-based mutations of key amino-acid residues confirm drug binding at both sites. Our results define the structural basis for binding of dihydropyridines and phenylalkylamines at their distinct receptor sites on CaV channels and offer key insights into their fundamental mechanisms of action and differential therapeutic uses in cardiovascular diseases.

EFFECTIVENESS OF LISINOPRIL AND AMLODIPINE COMBINATION AT HYPERTENSION WITH COMORBIDITY OF ARTERIOSCLEROSIS OBLITERANS IN GENERAL PRACTICE.

OBJECTIVE: The aim: To analyze the dynamics of daily monitoring of blood pressure, intracardiac (according to echocardiography), peripheral hemodynamics (according to ultrasound of the vessels of the lower extremity), the thickness of the intima-media complex (according to carotid sonography) in patients with hypertension the effect of treatment with a combination of lisinopril and amlodipine. PATIENTS AND METHODS: Materials and methods: The study included 40 patients with hypertension with 2 (29 patients) and 3 (11 patients) degrees of hypertension in combination with AOLE with I-III stages of chronic insufficiency of the lower extremity, which revealed hyperkinetic, eukinetic, and hypokinetic types of hypertension with a predominance of the sympathetic nervous system. The groups are comparable in age, sex, duration of hypertension, and medications received in the previous stages. For antihypertensive therapy, the most common drugs for use were selected - lisinopril + amplodipine in fixed doses of 10 and 5 mg, respectively. If after 2 weeks we did not reduce the mean level of SBP and DBP by 10% or more from baseline, we doubled the dose of lisinopril without changing the dose of amlodipine. RESULTS: Results: After 6 months of treatment, in particular, an increase in the pulse index - by 24.8%, a decrease in the resistance index - by 21.1%, an increase in linear and volumetric blood velocity - by 25.6% and 27.4%, respectively, while achieving the target blood pressure. CONCLUSION: Conclusions: It is proved that in the absence of individual contraindications the combination of lisinopril and amlodipine is optimal and universal for effective treatment of patients with hypertension in combination with AOLE in all types of central hemodynamics.

Amlodipine and Verapamil, Voltage-Gated Ca2+ Channel Inhibitors, Suppressed the Growth of Gastric Cancer Stem Cells.

BACKGROUND: The membrane transporters activated in cancer stem cells (CSCs) are the target of novel cancer therapies for gastric cancer. The present study investigated ion channel expression profiles in gastric CSCs (GCSCs). METHODS: Cells strongly expressing CD44 were separated from MKN74 cells, a human gastric cancer cell line, by fluorescence-activated cell sorting (FACS), and GCSCs were identified based on tumorsphere formation. Gene expression profiles in GCSCs were examined by a microarray analysis. RESULTS: Among MKN74 cells, CD44 messenger RNA levels were higher in CSCs than in non-CSCs. These CSCs also exhibited resistance to cisplatin. The microarray analysis revealed that the expression of several genes related to voltage-gated Ca2+ channels (VGCCs), including CACNA2D1 and CACNB4, was upregulated. The cytotoxicities of the CACNA2D1 inhibitor amlodipine and the CACNB4 inhibitor verapamil were greater at lower concentrations in CSCs than in non-CSCs, and markedly reduced tumorsphere numbers. Tumor volumes were significantly smaller in a xenograft nude mouse model treated with amlodipine or verapamil in combination with cisplatin than in that treated with cisplatin alone. CONCLUSIONS: The present results indicate that VGCCs play a role in maintaining CSCs, and demonstrated the potential of their specific inhibitors, amlodipine and verapamil, as targeted therapeutic agents against gastric cancer.