Nifedipine, A Promising Drug for Prevention of Heart Changes During Weightlessness

1988 ◽  
Vol 46 ◽  
pp. 130-131
Author(s):  
D.E. Philpott ◽  
K. Kato ◽  
J. Stevenson ◽  
J. Miguel ◽  
W. Sapp
Keyword(s):  
Calcium Channel ◽  
Structural Changes ◽  
Channel Blocker ◽  
Calcium Influx ◽  
Space Station ◽  
Recovery Phase ◽  
Channel Blockers ◽  
Simulated Weightlessness ◽  
Heart Attacks ◽  
Limited Success

NASA plans to have a space station operating in 1994 and is considering a 30 month Mars flight. These plans call for exposure to microgravity for longer periods of time than space travelers have endured to date. Vascular deconditioning is known to occur during space flight and during simulated weightlessness. The degree of deconditioning for these extended flights and the amount of possible reversibility is unknown. If a sudden demanding burden should be placed on the astronaut after prolonged deconditioning, there could be serious consequences. Exercise has been tried with limited success. What is needed is a counter measure to deconditioning. Calcium channel blockers are known to protect the heart during the recovery phase after heart attacks by regulating the calcium influx, thus protecting the cell and mitochondria from calcium overload. Sudden demands also increase blood flow, mimicking the post attack reperfusion, and could be serious for a deconditioned heart. We have found nifedipine, a calcium channel blocker, to be a promising drug for prevention of structural changes during simulated weightlessness.

Calcium channel blockers modulate airway constriction in the canine lung periphery

1991 ◽  
Vol 70 (2) ◽  
pp. 624-630 ◽  
Author(s):  
K. S. Lindeman ◽  
C. A. Hirshman ◽  
A. N. Freed
Keyword(s):  
Calcium Channel ◽  
Calcium Channel Blocker ◽  
Calcium Channel Blockers ◽  
Channel Blocker ◽  
Calcium Influx ◽  
Channel Blockers ◽  
Dry Air ◽  
Before And After ◽  
Dihydropyridine Calcium Channel Blocker ◽  
Lung Periphery

We studied the effect of two voltage-sensitive calcium channel blockers on Na2EDTA-induced bronchoconstriction in the canine lung periphery. A wedged bronchoscope technique was used to measure collateral system resistance before and after challenges with aerosolized Na2EDTA, hypocapnia, aerosolized acetylcholine, and increased flow of dry air in anesthetized mongrel dogs. Nifedipine, a dihydropyridine calcium channel blocker, reduced hypocapnia-induced bronchoconstriction by 88 +/- 6% (SE) but did not alter Na2EDTA-induced constriction. Verapamil, a phenylalkylamine calcium channel blocker, attenuated hypocapnia- and Na2EDTA-induced bronchoconstriction by 69 +/- 6 and 44 +/- 7%, respectively, but did not significantly alter responses to either acetylcholine or dry air challenge. We conclude that calcium influx through voltage-sensitive calcium channels, perhaps of the T subtype, has a limited role in the initiation of Na2EDTA-induced bronchoconstriction in the canine lung periphery.

Electroanalytical Methods for Determination of Calcium Channel Blockers

2019 ◽  
Vol 15 (3) ◽  
pp. 207-218 ◽  
Author(s):  
Fatma Ağın
Keyword(s):  
Calcium Channel ◽  
Calcium Channel Blockers ◽  
Channel Blocker ◽  
Heart Diseases ◽  
Dosage Forms ◽  
Channel Blockers ◽  
Electroanalytical Methods ◽  
Pharmaceutical Dosage Forms ◽  
Ischemic Heart Diseases

Background:Calcium Channel Blockers (CCBs) are widely used in the treatment of cardiovascular and ischemic heart diseases in recent years. They treat arrhythmias by reducing cardiac cycle contraction and also benefit ischemic heart diseases. Electroanalytical methods are very powerful analytical methods used in the pharmaceutical industry because of the determination of therapeutic agents and/or their metabolites in clinical samples at extremely low concentrations (10-50 ng/ml). The purpose of this review is to gather electroanalytical methods used for the determination of calcium channel blocker drugs in pharmaceutical dosage forms and biological media selected mainly from current articles.Methods:This review mainly includes recent determination studies of calcium channel blockers by electroanalytical methods from pharmaceutical dosage forms and biological samples. The studies of calcium channel blockers electroanalytical determination in the literature were reviewed and interpreted.Results:There are a lot of studies on amlodipine and nifedipine, but the number of studies on benidipine, cilnidipine, felodipine, isradipine, lercanidipine, lacidipine, levamlodipine, manidipine, nicardipine, nilvadipine, nimodipine, nisoldipine, nitrendipine, diltiazem, and verapamil are limited in the literature. In these studies, DPV and SWV are the most used methods. The other methods were used less for the determination of calcium channel blocker drugs.Conclusion:Electroanalytical methods especially voltammetric methods supply reproducible and reliable results for the analysis of the analyte. These methods are simple, more sensitive, rapid and inexpensive compared to the usually used spectroscopic and chromatographic methods.

scholarly journals L-type calcium channel blocker increases VEGF concentrations in retinal cells and human serum

2021 ◽  
Author(s):  
Anmol Kumar ◽  
Stefan Mutter ◽  
Erika Parente ◽  
Valma Harjutsalo ◽  
Raija Lithovius ◽  
...  
Keyword(s):  
Calcium Channel ◽  
Human Serum ◽  
Channel Blocker ◽  
Channel Blockers ◽  
Vascular Endothelial ◽  
Retinal Cells ◽  
Diabetic Eye Disease ◽  
Design And Methods ◽  
Endothelial Growth Factor

Objective: Vascular endothelial growth factor (VEGF) plays a key role in diabetic retinopathy (DR). L-type calcium channel blockers (LTCCBs) have been widely used as antihypertensive medication (AHM), but their association with VEGF and DR is still unclear. Therefore, we explored the effect of LTCCBs compared to other AHMs on VEGF concentrations in retinal cells and human serum. Furthermore, we evaluated the association between the use of LTCCBs and the risk of severe diabetic eye disease (SDED). Research design and methods: Muller cells (MIO-M1) were cultured as per recommended protocol and treated with LTCCBs and other AHMs. VEGF secreted from cells were collected at 24 hours intervals. In an interventional study, 39 individuals received LTCCBs or other AHM for four weeks with a four-week wash-out placebo period between treatments. VEGF was measured during the medication and placebo periods. Finally, we evaluated the risk of SDED associated with LTCCB usage in 192 individuals from the FinnDiane Study in an oberservational setting. Results: In the cell cultures, medium VEGF concentration increased time-dependently after amlodipine (p<0.01) treatment, but not after losartan (p>0.01), or lisinopril (p>0.01). Amlodipine, but no other AHM, increased serum VEGF concentration (p<0.05) during the interventional clinical study. The usage of LTCCB was not associated with the risk of SDED in the observational study. Conclusions: LTCCB increases VEGF concentrations in retinal cells and human serum. However, the usage of LTCCBs does not appear to be associated with SDED in adults with type 1 diabetes.

Pharmacologically and Functionally Distinct Calcium Currents of Stomatogastric Neurons

1998 ◽  
Vol 79 (4) ◽  
pp. 2070-2081 ◽  
Author(s):  
Laura M. Hurley ◽  
Katherine Graubard
Keyword(s):  
Neuromuscular Junction ◽  
Calcium Channel ◽  
Calcium Current ◽  
Calcium Influx ◽  
Outward Current ◽  
Calcium Currents ◽  
High Threshold ◽  
Channel Blockers ◽  
Postsynaptic Potentials ◽  
Different Types

Hurley, Laura M. and Katherine Graubard. Pharmacologically and functionally distinct calcium currents of stomatogastric neurons. J. Neurophysiol. 79: 2070–2081, 1998. Previous studies have suggested the presence of different types of calcium channels in different regions of stomatogastric neurons. We sought to pharmacologically separate these calcium channel types. We used two different preparations from different regions of stomatogastric neurons to screen a range of selective calcium channel blockers. The two preparations were isolated cell bodies in culture, in which calcium current was measured directly, and isolated neuromuscular junction, in which synaptic transmission was the indirect assay for presynaptic calcium influx. The selective blockers were two different dihydropyridines, ω-Agatoxin IVA, and ω-Conotoxin GVIA. Cultured cell bodies possessed both high-threshold calcium current and calcium-activated outward current, similar to intact neurons. The calcium current had transient and maintained components, but both components had the same voltage dependence of activation and inactivation. Dihydropyridines at ≥10 μM blocked both high-threshold calcium current and calcium-activated outward current. Nanomolar doses of ω-Agatoxin IVA did not block calcium current, but micromolar doses did. ω-Conotoxin GVIA did not block either current. In contrast, at the neuromuscular junction, dihydropyridines reduced the amplitude of postsynaptic potentials by only a modest amount, whereas ω-Agatoxin IVA at doses as low as 64 nM reduced the amplitude of postsynaptic potentials almost entirely. These effects were presynaptic. ω-Conotoxin GVIA did not change the amplitude of postsynaptic potentials. The different pharmacological profiles of the two isolated preparations suggest that there are at least two different types of calcium channel in stomatogastric neurons and that ω-Agatoxin IVA and dihydropridines can be used to pharmacologically distinguish them.

Influence of Nifedipine on the Visual Fields of Patients with Optic-Nerve-Head Diseases

1994 ◽  
Vol 4 (1) ◽  
pp. 24-28 ◽  
Author(s):  
A.Z. Gaspar ◽  
J. Flammer ◽  
PH. Hendrickson
Keyword(s):  
Optic Nerve ◽  
Visual Field ◽  
Calcium Channel ◽  
Calcium Channel Blocker ◽  
Optic Nerve Head ◽  
Channel Blocker ◽  
Glaucoma Patient ◽  
Visual Fields ◽  
Visual Field Defects ◽  
Channel Blockers

Calcium-channel blockers have long been employed in coronary disease, and recent investigations have indicated their efficacy in improving the visual field in low-tension glaucoma or presumed vasospasm, possibly by enhancing ocular circulation. We evaluated the short-term influence of a typical calcium-channel blocker, nifedipine, on 59 patients with visual-field defects, some with optic-nerve-head pathology (n = 38) and some with normal-appearing optic nerve heads (n = 21). On the average, a statistically significant improvement of 1.2 dB was observed. Different types of patients, however, behaved quite differently. The younger the patient, the greater the improvement. Patients with normal optic nerve heads improved by 1.54 dB, whereas patients with optic-nerve-head excavation improved by only 0.66 dB. No response was observed in patients with anterior ischemic neuropathy. Marked deterioration was noted in one glaucoma patient with low systemic blood pressure. The visual-field changes were observed in the scotomatous and non-scotomatous areas. Thus, the calcium-channel blocker nifedipine can be effective in some selected diseases whose pathogenesis probably involves vascular dysregulation though it may even be contraindicated in others

scholarly journals Aberrant Exon 8/8a Splicing by Downregulated PTBP (Polypyrimidine Tract-Binding Protein) 1 Increases Ca V 1.2 Dihydropyridine Resistance to Attenuate Vasodilation

2020 ◽  
Vol 40 (10) ◽  
pp. 2440-2453
Author(s):  
Jianzhen Lei ◽  
Xiaoxin Liu ◽  
Miaomiao Song ◽  
Yingying Zhou ◽  
Jia Fan ◽  
...  
Keyword(s):  
Calcium Channel ◽  
Calcium Channel Blocker ◽  
Channel Blocker ◽  
Binding Protein ◽  
Expression Patterns ◽  
Mesenteric Arteries ◽  
Channel Blockers ◽  
Polypyrimidine Tract ◽  
Polypyrimidine Tract Binding ◽  
Polypyrimidine Tract Binding Protein

Objective: Calcium channel blockers, such as dihydropyridines, are commonly used to inhibit enhanced activity of vascular Ca V 1.2 channels in hypertension. However, patients who are insensitive to such treatments develop calcium channel blocker-resistant hypertension. The function of Ca V 1.2 channel is diversified by alternative splicing, and the splicing factor PTBP (polypyrimidine tract-binding protein) 1 influences the utilization of mutually exclusive exon 8/8a of the Ca V 1.2 channel during neuronal development. Nevertheless, whether and how PTBP1 makes a role in the calcium channel blocker sensitivity of vascular Ca V 1.2 channels, and calcium channel blocker-induced vasodilation remains unknown. Approach and Results: We detected high expression of PTBP1 and, inversely, low expression of exon 8a in Ca V 1.2 channels (Ca V 1.2 E8a ) in rat arteries. In contrast, the opposite expression patterns were observed in brain and heart tissues. In comparison to normotensive rats, the expressions of PTBP1 and Ca V 1.2 E8a channels were dysregulated in mesenteric arteries of hypertensive rats. Notably, PTBP1 expression was significantly downregulated, and Ca V 1.2 E8a channels were aberrantly increased in dihydropyridine-resistant arteries compared with dihydropyridine-sensitive arteries of rats and human. In rat vascular smooth muscle cells, PTBP1 knockdown resulted in shifting of Ca V 1.2 exon 8 to 8a. Using patch-clamp recordings, we demonstrated a concomitant reduction of sensitivity of Ca V 1.2 channels to nifedipine, due to the higher expression of Ca V 1.2 E8a isoform. In vascular myography experiments, small interfering RNA-mediated knockdown of PTBP1 attenuated nifedipine-induced vasodilation of rat mesenteric arteries. Conclusions: PTBP1 finely modulates the sensitivities of Ca V 1.2 channels to dihydropyridine by shifting the utilization of exon 8/8a and resulting in changes of responses in dihydropyridine-induced vasodilation.

Praziquantel and the benzodiazepine Ro 11-3128 do not compete for the same binding sites in schistosomes

Parasitology ◽  
2007 ◽  
Vol 135 (1) ◽  
pp. 47-54 ◽  
Author(s):  
L. PICA-MATTOCCIA ◽  
A. RUPPEL ◽  
C. M. XIA ◽  
D. CIOLI
Keyword(s):  
Calcium Channel ◽  
Binding Sites ◽  
Calcium Influx ◽  
Cytochalasin D ◽  
The Other ◽  
Channel Blockers ◽  
Spastic Paralysis ◽  
Receptor Sites

SUMMARYThe benzodiazepine Ro 11-3128 (methyl-clonazepam) presents several similarities with praziquantel with regard to its anti-schistosomal mode of action, since both drugs cause spastic paralysis, calcium influx and tegumental disruption in the parasites. In order to know whether the two compounds share the same binding sites in the schistosomes, we performed in vivo and in vitro competition experiments. We took advantage of the fact that Ro 11-3128 is active against immature Schistosoma mansoni (whereas praziquantel is inactive), and praziquantel is active against S. japonicum (which is insensitive to Ro 11-3128). An excess of praziquantel did not inhibit the activity of Ro 11-3128 against immature S. mansoni and an excess of Ro 11-3128 did not inhibit the activity of praziquantel against S. japonicum, suggesting that the schistosome binding sites of the two drugs are different. On the other hand, cytochalasin D, an agent known to perturb – among other things – calcium channel function, was capable of inhibiting the schistosomicidal activity of both praziquantel and Ro 11-3128, thus adding another element of similarity between the two anti-schistosomal agents. A similar, albeit partial, inhibition of the schistosomicidal activity of the two drugs was exerted by some of the classical calcium channel blockers. Taken together, these results suggest that praziquantel and Ro 11-3128, although binding to different schistosome receptor sites, may use the same basic anti-schistosomal effector mechanisms.

scholarly journals Densitas tulang mandibula pengguna obat anti hipertensi calcium channel blocker (CCB) melalui radiograf panoramik

2020 ◽  
Vol 4 (2) ◽  
pp. 1
Author(s):  
Gunawan Gunawan ◽  
Suhardjo Sitam ◽  
Lusi Epsilawati
Keyword(s):  
Bone Density ◽  
Calcium Channel ◽  
Calcium Channel Blocker ◽  
Calcium Channel Blockers ◽  
Drug Users ◽  
Channel Blocker ◽  
Antihypertensive Drugs ◽  
Panoramic Radiograph ◽  
Channel Blockers ◽  
Hypertensive Drug

Objectives: The purpose of this research was to describe radiographic density of mandibular bone in calcium channel blocker anti-hypertensive drug users. Bone density in the mandible is assessed from the trabecular. Panoramic radiograph is a routine examination that is often done in dentistry that can be used to assess changes in quality in the form of changes in bone density in users of anti-hypertensive calcium channel blockers Material and Methods: This research is a descriptive study of 21 panoramic radiographs of calcium channel blocker anti-hypertensive drug users aged 40-75 years. Panoramic radiograph archive density checks in the distal region of the foramen mentale and the mandibular angular region using software image j, with the final result was the percentage between bone and marrow. Results: This research showed the average radiographic density in male using calcium channel blocker antihypertensive drugs was 18.81% and the average radiographic density in female was 20.92%. Conclusion: Based on the results of the study found that the average radiographic density of female patients taking antihypertensive drugs calcium channel blockers was higher than male.

scholarly journals A Systematic Review on 1, 4-Dihydropyridines and its Analogues: An Elite Scaffold

2021 ◽  
Vol 12 (3) ◽  
pp. 3117-3134
Keyword(s):  
Myocardial Infarction ◽  
Systematic Review ◽  
Clinical Trials ◽  
Calcium Channels ◽  
Calcium Channel ◽  
Calcium Channel Blockers ◽  
Calcium Influx ◽  
Channel Blockers ◽  
Neuroprotective Effects ◽  
Dihydropyridine Derivatives

1,4-Dihydropyridines are a group of pyridine-based molecules possessing a magnificent set of biological and therapeutic potentials. Belonging to the class of calcium channel blockers, they are known to be effective in the conditions, angina, hypertension, myocardial infarction and show vasodilatory and cardiac depressant effects. Hypotensive, antimicrobial, anticancer, anticoagulant, antioxidant, anticonvulsant, antimalarial, antiulcer, and neuroprotective effects have been reported with their rational use. The effects are precipitated in response to inhibition of calcium channels, gradually restricting calcium influx. Drugs like nifedipine, felodipine, and amlodipine are commonly used clinically. Several other drugs belonging to this class have been under clinical trials. The present review focuses on the various 1,4-dihydropyridine derivatives and their pharmacological actions.

scholarly journals Calcium channel blockers do not protect against saturated fatty acid-induced ER stress and apoptosis in human pancreatic β-cells

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Jan Šrámek ◽  
Vlasta Němcová ◽  
Jan Kovář
Keyword(s):  
Er Stress ◽  
Calcium Channel ◽  
Cell Lines ◽  
Calcium Channel Blockers ◽  
Calcium Influx ◽  
Saturated Fatty Acids ◽  
Channel Blockers ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells

AbstractIt was evidenced that saturated fatty acids (FAs) have a detrimental effect on pancreatic β-cells function and survival, leading to endoplasmic reticulum (ER) calcium release, ER stress, and apoptosis. In the present study, we have tested the effect of three calcium influx inhibitors, i.e., diazoxide, nifedipine, and verapamil, on the apoptosis-inducing effect of saturated stearic acid (SA) in the human pancreatic β-cell lines NES2Y and 1.1B4. We have demonstrated that the application of all three calcium influx inhibitors tested has no inhibitory effect on SA-induced ER stress and apoptosis in both tested cell lines. Moreover, these inhibitors have pro-apoptotic potential per se at higher concentrations. Interestingly, these findings are in contradiction with those obtained with rodent cell lines and islets. Thus our data obtained with human β-cell lines suggest that the prospective usage of calcium channel blockers for prevention and therapy of type 2 diabetes mellitus, developed with the contribution of the saturated FA-induced apoptosis of β-cells, seems rather unlikely.

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