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1.
Discov Med ; 36(184): 882-897, 2024 May.
Article in English | MEDLINE | ID: mdl-38798249

ABSTRACT

Cardiovascular disease stands as the leading cause of death globally, with hypertension emerging as an independent risk factor for its development. The worldwide prevalence of hypertension hovers around 30%, encompassing a staggering 1.2 billion patients, and continues to escalate annually. Medication plays a pivotal role in managing hypertension, not only effectively regulating blood pressure (BP) but also substantially mitigating the occurrence of cardiovascular and cerebrovascular diseases. This review comprehensively outlines the categories, mechanisms, clinical applications, and drawbacks of conventional antihypertensive drugs. It delves into the five primary pharmacological classifications, namely ß-receptor blockers, calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), and diuretics. The emphasis is placed on elucidating the mechanisms, advantages, and research progress of novel antihypertensive drugs targeting emerging areas. These include mineralocorticoid receptor antagonists (MRAs), atrial natriuretic peptides (ANPs), neutral endopeptidase inhibitors (NEPIs), sodium-dependent glucose transporter 2 inhibitors (SGLT-2Is), glucagon-like peptide-1 receptor agonists (GLP-1RAs), endothelin receptor antagonists (ERAs), soluble guanylate cyclase (sGC) agonists, brain aminopeptidase A inhibitors (APAIs), and small interfering ribonucleic acids (siRNAs) targeting hepatic angiotensinogen. Compared to conventional antihypertensive drugs, these novel alternatives exhibit favorable antihypertensive effects with minimal adverse reactions. This review serves as a valuable reference for future research and the clinical application of antihypertensive drugs.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors , Antihypertensive Agents , Hypertension , Humans , Antihypertensive Agents/therapeutic use , Antihypertensive Agents/pharmacology , Hypertension/drug therapy , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Angiotensin Receptor Antagonists/therapeutic use , Calcium Channel Blockers/therapeutic use , Calcium Channel Blockers/pharmacology , Animals , Adrenergic beta-Antagonists/therapeutic use , Adrenergic beta-Antagonists/pharmacology , Diuretics/therapeutic use , Diuretics/pharmacology , Mineralocorticoid Receptor Antagonists/therapeutic use
2.
Int J Mol Sci ; 25(9)2024 Apr 26.
Article in English | MEDLINE | ID: mdl-38731963

ABSTRACT

Venom peptides have evolved to target a wide range of membrane proteins through diverse mechanisms of action and structures, providing promising therapeutic leads for diseases, including pain, epilepsy, and cancer, as well as unique probes of ion channel structure-function. In this work, a high-throughput FLIPR window current screening assay on T-type CaV3.2 guided the isolation of a novel peptide named ω-Buthitoxin-Hf1a from scorpion Hottentotta franzwerneri crude venom. At only 10 amino acid residues with one disulfide bond, it is not only the smallest venom peptide known to target T-type CaVs but also the smallest structured scorpion venom peptide yet discovered. Synthetic Hf1a peptides were prepared with C-terminal amidation (Hf1a-NH2) or a free C-terminus (Hf1a-OH). Electrophysiological characterization revealed Hf1a-NH2 to be a concentration-dependent partial inhibitor of CaV3.2 (IC50 = 1.18 µM) and CaV3.3 (IC50 = 0.49 µM) depolarized currents but was ineffective at CaV3.1. Hf1a-OH did not show activity against any of the three T-type subtypes. Additionally, neither form showed activity against N-type CaV2.2 or L-type calcium channels. The three-dimensional structure of Hf1a-NH2 was determined using NMR spectroscopy and used in docking studies to predict its binding site at CaV3.2 and CaV3.3. As both CaV3.2 and CaV3.3 have been implicated in peripheral pain signaling, the analgesic potential of Hf1a-NH2 was explored in vivo in a mouse model of incision-induced acute post-surgical pain. Consistent with this role, Hf1a-NH2 produced antiallodynia in both mechanical and thermal pain.


Subject(s)
Calcium Channels, T-Type , Disease Models, Animal , Hyperalgesia , Pain, Postoperative , Scorpion Venoms , Animals , Calcium Channels, T-Type/metabolism , Calcium Channels, T-Type/chemistry , Mice , Scorpion Venoms/chemistry , Scorpion Venoms/pharmacology , Hyperalgesia/drug therapy , Hyperalgesia/metabolism , Pain, Postoperative/drug therapy , Pain, Postoperative/metabolism , Calcium/metabolism , Male , Humans , Calcium Channel Blockers/pharmacology , Calcium Channel Blockers/chemistry
3.
Sci Rep ; 14(1): 11720, 2024 05 22.
Article in English | MEDLINE | ID: mdl-38778154

ABSTRACT

We studied the inhibitory actions of docosahexaenoic acid (DHA) on the contractions induced by carbachol (CCh), angiotensin II (Ang II), and bradykinin (BK) in guinea pig (GP) gastric fundus smooth muscle (GFSM), particularly focusing on the possible inhibition of store-operated Ca2+ channels (SOCCs). DHA significantly suppressed the contractions induced by CCh, Ang II, and BK; the inhibition of BK-induced contractions was the strongest. Although all contractions were greatly dependent on external Ca2+, more than 80% of BK-induced contractions remained even in the presence of verapamil, a voltage-dependent Ca2+ channel inhibitor. BK-induced contractions in the presence of verapamil were not suppressed by LOE-908 (a receptor-operated Ca2+ channel (ROCC) inhibitor) but were suppressed by SKF-96365 (an SOCC and ROCC inhibitor). BK-induced contractions in the presence of verapamil plus LOE-908 were strongly inhibited by DHA. Furthermore, DHA inhibited GFSM contractions induced by cyclopiazonic acid (CPA) in the presence of verapamil plus LOE-908 and inhibited the intracellular Ca2+ increase due to Ca2+ addition in CPA-treated 293T cells. These findings indicate that Ca2+ influx through SOCCs plays a crucial role in BK-induced contraction in GP GFSM and that this inhibition by DHA is a new mechanism by which this fatty acid inhibits GFSM contractions.


Subject(s)
Angiotensin II , Bradykinin , Carbachol , Docosahexaenoic Acids , Gastric Fundus , Muscle Contraction , Muscle, Smooth , Animals , Guinea Pigs , Docosahexaenoic Acids/pharmacology , Bradykinin/pharmacology , Muscle, Smooth/drug effects , Muscle, Smooth/physiology , Muscle, Smooth/metabolism , Carbachol/pharmacology , Muscle Contraction/drug effects , Angiotensin II/pharmacology , Gastric Fundus/drug effects , Gastric Fundus/physiology , Gastric Fundus/metabolism , Verapamil/pharmacology , Calcium/metabolism , Male , Humans , Calcium Channels/metabolism , HEK293 Cells , Calcium Channel Blockers/pharmacology , Imidazoles/pharmacology
4.
Molecules ; 29(10)2024 May 12.
Article in English | MEDLINE | ID: mdl-38792145

ABSTRACT

The Cupressaceae family includes species considered to be medicinal. Their essential oil is used for headaches, colds, cough, and bronchitis. Cedar trees like Chamaecyparis lawsoniana (C. lawsoniana) are commonly found in urban areas. We investigated whether C. lawsoniana exerts some of its effects by modifying airway smooth muscle (ASM) contractility. The leaves of C. lawsoniana (363 g) were pulverized mechanically, and extracts were obtained by successive maceration 1:10 (w:w) with methanol/CHCl3. Guinea pig tracheal rings were contracted with KCl, tetraethylammonium (TEA), histamine (HIS), or carbachol (Cch) in organ baths. In the Cch experiments, tissues were pre-incubated with D-600, an antagonist of L-type voltage-dependent Ca2+ channels (L-VDCC) before the addition of C. lawsoniana. Interestingly, at different concentrations, C. lawsoniana diminished the tracheal contractions induced by KCl, TEA, HIS, and Cch. In ASM cells, C. lawsoniana significantly diminished L-type Ca2+ currents. ASM cells stimulated with Cch produced a transient Ca2+ peak followed by a sustained plateau maintained by L-VDCC and store-operated Ca2+ channels (SOCC). C. lawsoniana almost abolished this last response. These results show that C. lawsoniana, and its active metabolite quercetin, relax the ASM by inhibiting the L-VDCC and SOCC; further studies must be performed to obtain the complete set of metabolites of the extract and study at length their pharmacological properties.


Subject(s)
Calcium , Chamaecyparis , Muscle Contraction , Muscle, Smooth , Plant Extracts , Quercetin , Trachea , Animals , Guinea Pigs , Muscle, Smooth/drug effects , Muscle, Smooth/metabolism , Muscle Contraction/drug effects , Quercetin/pharmacology , Quercetin/chemistry , Trachea/drug effects , Trachea/metabolism , Plant Extracts/pharmacology , Plant Extracts/chemistry , Chamaecyparis/chemistry , Calcium/metabolism , Male , Calcium Channel Blockers/pharmacology , Histamine/metabolism , Calcium Channels, L-Type/metabolism , Plant Leaves/chemistry
5.
Channels (Austin) ; 18(1): 2335469, 2024 Dec.
Article in English | MEDLINE | ID: mdl-38564754

ABSTRACT

Studies in genetically modified animals and human genetics have recently provided new insight into the role of voltage-gated L-type Ca2+ channels in human disease. Therefore, the inhibition of L-type Ca2+ channels in vivo in wildtype and mutant mice by potent dihydropyridine (DHP) Ca2+ channel blockers serves as an important pharmacological tool. These drugs have a short plasma half-life in humans and especially in rodents and show high first-pass metabolism upon oral application. In the vast majority of in vivo studies, they have therefore been delivered through parenteral routes, mostly subcutaneously or intraperitoneally. High peak plasma concentrations of DHPs cause side effects, evident as DHP-induced aversive behaviors confounding the interpretation of behavioral readouts. Nevertheless, pharmacokinetic data measuring the exposure achieved with these applications are sparse. Moreover, parenteral injections require animal handling and can be associated with pain, discomfort and stress which could influence a variety of physiological processes, behavioral and other functional readouts. Here, we describe a noninvasive oral application of the DHP isradipine by training mice to quickly consume small volumes of flavored yogurt that can serve as drug vehicle. This procedure does not require animal handling, allows repeated drug application over several days and reproducibly achieves peak plasma concentrations over a wide range previously shown to be well-tolerated in humans. This protocol should facilitate ongoing nonclinical studies in mice exploring new indications for DHP Ca2+ channel blockers.


Subject(s)
Calcium Channel Blockers , Calcium Channels, L-Type , Mice , Humans , Animals , Isradipine/pharmacology , Isradipine/metabolism , Calcium Channel Blockers/pharmacology , Calcium Channels, L-Type/genetics , Calcium Channels, L-Type/metabolism , Administration, Oral
6.
Proc Natl Acad Sci U S A ; 121(17): e2303664121, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38621124

ABSTRACT

Brain-derived neurotrophic factor (BDNF) plays a critical role in synaptic physiology, as well as mechanisms underlying various neuropsychiatric diseases and their treatment. Despite its clear physiological role and disease relevance, BDNF's function at the presynaptic terminal, a fundamental unit of neurotransmission, remains poorly understood. In this study, we evaluated single synapse dynamics using optical imaging techniques in hippocampal cell cultures. We find that exogenous BDNF selectively increases evoked excitatory neurotransmission without affecting spontaneous neurotransmission. However, acutely blocking endogenous BDNF has no effect on evoked or spontaneous release, demonstrating that different approaches to studying BDNF may yield different results. When we suppressed BDNF-Tropomyosin receptor kinase B (TrkB) activity chronically over a period of days to weeks using a mouse line enabling conditional knockout of TrkB, we found that evoked glutamate release was significantly decreased while spontaneous release remained unchanged. Moreover, chronic blockade of BDNF-TrkB activity selectively downscales evoked calcium transients without affecting spontaneous calcium events. Via pharmacological blockade by voltage-gated calcium channel (VGCC) selective blockers, we found that the changes in evoked calcium transients are mediated by the P/Q subtype of VGCCs. These results suggest that BDNF-TrkB activity increases presynaptic VGCC activity to selectively increase evoked glutamate release.


Subject(s)
Brain-Derived Neurotrophic Factor , Calcium , Brain-Derived Neurotrophic Factor/metabolism , Calcium/metabolism , Synaptic Transmission/physiology , Synapses/metabolism , Calcium Channel Blockers/pharmacology , Calcium, Dietary , Receptor, trkB/genetics , Receptor, trkB/metabolism , Glutamates/metabolism
7.
Funct Integr Genomics ; 24(3): 77, 2024 Apr 18.
Article in English | MEDLINE | ID: mdl-38632140

ABSTRACT

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.


Subject(s)
Amlodipine , Calcium Signaling , Stomach Neoplasms , Synaptotagmins , Humans , Amlodipine/pharmacology , Amlodipine/therapeutic use , Calcium/metabolism , Calcium Signaling/drug effects , Cell Line, Tumor , Cell Proliferation , Gene Expression Regulation, Neoplastic , Stomach Neoplasms/drug therapy , Stomach Neoplasms/genetics , Stomach Neoplasms/metabolism , Stomach Neoplasms/pathology , Synaptotagmins/antagonists & inhibitors , Synaptotagmins/genetics , Synaptotagmins/metabolism , Calcium Channel Blockers/pharmacology
8.
Chem Pharm Bull (Tokyo) ; 72(4): 399-407, 2024.
Article in English | MEDLINE | ID: mdl-38644198

ABSTRACT

Ryanodine receptor 2 (RyR2) is a large Ca2+-release channel in the sarcoplasmic reticulum (SR) of cardiac muscle cells. It serves to release Ca2+ from the SR into the cytosol to initiate muscle contraction. RyR2 overactivation is associated with arrhythmogenic cardiac disease, but few specific inhibitors have been reported so far. Here, we identified an RyR2-selective inhibitor 1 from the chemical compound library and synthesized it from glycolic acid. Synthesis of various derivatives to investigate the structure-activity relationship of each substructure afforded another two RyR2-selective inhibitors 6 and 7, among which 6 was the most potent. Notably, compound 6 also inhibited Ca2+ release in cells expressing the RyR2 mutants R2474S, R4497C and K4750Q, which are associated with cardiac arrhythmias such as catecholaminergic polymorphic ventricular tachycardia (CPVT). This inhibitor is expected to be a useful tool for research on the structure and dynamics of RyR2, as well as a lead compound for the development of drug candidates to treat RyR2-related cardiac disease.


Subject(s)
Calcium Channel Blockers , Ryanodine Receptor Calcium Release Channel , Humans , Calcium/metabolism , Dose-Response Relationship, Drug , Drug Discovery , HEK293 Cells , Molecular Structure , Ryanodine Receptor Calcium Release Channel/drug effects , Ryanodine Receptor Calcium Release Channel/genetics , Ryanodine Receptor Calcium Release Channel/metabolism , Structure-Activity Relationship , Calcium Channel Blockers/chemistry , Calcium Channel Blockers/pharmacology , Anti-Arrhythmia Agents/chemistry , Anti-Arrhythmia Agents/pharmacology , Tachycardia, Ventricular/drug therapy , Tachycardia, Ventricular/genetics
9.
Drug Discov Today ; 29(6): 103995, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38670255

ABSTRACT

Calcium ion dysregulation exerts profound effects on various physiological activities such as tumor proliferation, migration, and drug resistance. Calcium-related channels play a regulatory role in maintaining calcium ion homeostasis, with most channels being highly expressed in tumor cells. Additionally, these channels serve as potential drug targets for the development of antitumor medications. In this review, we first discuss the current research status of these pathways, examining how they modulate various tumor functions such as epithelial-mesenchymal transition (EMT), metabolism, and drug resistance. Simultaneously, we summarize the recent progress in the study of novel small-molecule drugs over the past 5 years and their current status.


Subject(s)
Antineoplastic Agents , Calcium Channel Blockers , Calcium Channels , Epithelial-Mesenchymal Transition , Neoplasms , Humans , Neoplasms/drug therapy , Neoplasms/metabolism , Neoplasms/pathology , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Calcium Channels/metabolism , Animals , Epithelial-Mesenchymal Transition/drug effects , Calcium Channel Blockers/pharmacology , Calcium Channel Blockers/therapeutic use , Drug Development/methods , Drug Resistance, Neoplasm , Calcium/metabolism
10.
Cell Res ; 34(6): 440-450, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38605177

ABSTRACT

The Cav3.2 subtype of T-type calcium channels has been targeted for developing analgesics and anti-epileptics for its role in pain and epilepsy. Here we present the cryo-EM structures of Cav3.2 alone and in complex with four T-type calcium channel selective antagonists with overall resolutions ranging from 2.8 Å to 3.2 Å. The four compounds display two binding poses. ACT-709478 and TTA-A2 both place their cyclopropylphenyl-containing ends in the central cavity to directly obstruct ion flow, meanwhile extending their polar tails into the IV-I fenestration. TTA-P2 and ML218 project their 3,5-dichlorobenzamide groups into the II-III fenestration and place their hydrophobic tails in the cavity to impede ion permeation. The fenestration-penetrating mode immediately affords an explanation for the state-dependent activities of these antagonists. Structure-guided mutational analysis identifies several key residues that determine the T-type preference of these drugs. The structures also suggest the role of an endogenous lipid in stabilizing drug binding in the central cavity.


Subject(s)
Calcium Channel Blockers , Calcium Channels, T-Type , Cryoelectron Microscopy , Calcium Channels, T-Type/metabolism , Calcium Channels, T-Type/chemistry , Humans , Calcium Channel Blockers/chemistry , Calcium Channel Blockers/pharmacology , Binding Sites , Protein Binding , Models, Molecular , HEK293 Cells
11.
Toxicology ; 505: 153809, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38648961

ABSTRACT

The present work, using chromaffin cells of bovine adrenal medullae (BCCs), aims to describe what type of ionic current alterations induced by lead (Pb2+) underlies its effects reported on synaptic transmission. We observed that the acute application of Pb2+ lead to a drastic depression of neurotransmitters release in a concentration-dependent manner when the cells were stimulated with both K+ or acetylcholine, with an IC50 of 119,57 µM and of 5,19 µM, respectively. This effect was fully recovered after washout. Pb2+ also blocked calcium channels of BCCs in a time- and concentration-dependent manner with an IC50 of 6,87 µM. This blockade was partially reversed upon washout. This compound inhibited the calcium current at all test potentials and shows a shift of the I-V curve to more negative values of about 8 mV. The sodium current was not blocked by acute application of high Pb2+ concentrations. Voltage-dependent potassium current was also shortly affected by high Pb2+. Nevertheless, the calcium- and voltage-dependent potassium current was drastically depressed in a dose-dependent manner, with an IC50 of 24,49 µM. This blockade was related to the prevention of Ca2+ influx through voltage-dependent calcium channels coupled to Ca2+-activated K+-channels (BK) instead a direct linking to these channels. Under current-clamp conditions, BCCs exhibit a resting potential of -52.7 mV, firing spontaneous APs (1-2 spikes/s) generated by the opening of Na+ and Ca2+-channels, and terminated by the activation of K+ channels. In spite of the effect on ionic channels exerted by Pb2+, we found that Pb2+ didn't alter cellular excitability, no modification of the membrane potential, and no effect on action potential firing. Taken together, these results point to a neurotoxic action evoked by Pb2+ that is associated with changes in neurotransmitter release by blocking the ionic currents responsible for the calcium influx.


Subject(s)
Calcium Channels , Chromaffin Cells , Lead , Neurotransmitter Agents , Animals , Chromaffin Cells/drug effects , Chromaffin Cells/metabolism , Lead/toxicity , Cattle , Calcium Channels/metabolism , Calcium Channels/drug effects , Neurotransmitter Agents/pharmacology , Cells, Cultured , Dose-Response Relationship, Drug , Calcium Channel Blockers/pharmacology , Synaptic Transmission/drug effects , Calcium/metabolism , Acetylcholine/metabolism
12.
Arch Toxicol ; 98(6): 1827-1842, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38563869

ABSTRACT

Aminoglycosides are commonly used antibiotics for treatment of gram-negative bacterial infections, however, they might act on inner ear, leading to hair-cell death and hearing loss. Currently, there is no targeted therapy for aminoglycoside ototoxicity, since the underlying mechanisms of aminoglycoside-induced hearing impairments are not fully defined. This study aimed to investigate whether the calcium channel blocker verapamil and changes in intracellular & extracellular calcium could ameliorate aminoglycoside-induced ototoxicity in zebrafish. The present findings showed that a significant decreased number of neuromasts in the lateral lines of zebrafish larvae at 5 days' post fertilization after neomycin (20 µM) and gentamicin (20 mg/mL) exposure, which was prevented by verapamil. Moreover, verapamil (10-100 µM) attenuated aminoglycoside-induced toxic response in different external calcium concentrations (33-3300 µM). The increasing extracellular calcium reduced hair cell loss from aminoglycoside exposure, while lower calcium facilitated hair cell death. In contrast, calcium channel activator Bay K8644 (20 µM) enhanced aminoglycoside-induced ototoxicity and reversed the protective action of higher external calcium on hair cell loss. However, neomycin-elicited hair cell death was not altered by caffeine, ryanodine receptor (RyR) agonist, and RyR antagonists, including thapsigargin, ryanodine, and ruthenium red. The uptake of neomycin into hair cells was attenuated by verapamil and under high external calcium concentration. Consistently, the production of reactive oxygen species (ROS) in neuromasts exposed to neomycin was also reduced by verapamil and high external calcium. Significantly, zebrafish larvae when exposed to neomycin exhibited decreased swimming distances in reaction to droplet stimulus when compared to the control group. Verapamil and elevated external calcium effectively protected the impaired swimming ability of zebrafish larvae induced by neomycin. These data imply that prevention of hair cell damage correlated with swimming behavior against aminoglycoside ototoxicity by verapamil and higher external calcium might be associated with inhibition of excessive ROS production and aminoglycoside uptake through cation channels. These findings indicate that calcium channel blocker and higher external calcium could be applied to protect aminoglycoside-induced listening impairments.


Subject(s)
Anti-Bacterial Agents , Calcium Channel Blockers , Calcium , Gentamicins , Hair Cells, Auditory , Neomycin , Verapamil , Zebrafish , Animals , Calcium Channel Blockers/pharmacology , Calcium/metabolism , Verapamil/pharmacology , Neomycin/toxicity , Hair Cells, Auditory/drug effects , Hair Cells, Auditory/metabolism , Gentamicins/toxicity , Anti-Bacterial Agents/toxicity , Reactive Oxygen Species/metabolism , Ototoxicity/prevention & control , Aminoglycosides/toxicity , Lateral Line System/drug effects , Larva/drug effects , Hearing Loss/chemically induced , Hearing Loss/prevention & control
13.
Eur J Pharmacol ; 971: 176489, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38492875

ABSTRACT

Substance abuse disorder is a chronic condition for which pharmacological treatment options remain limited. L-type calcium channels (LTCC) have been implicated in drug-related plasticity and behavior. Specifically, dopaminergic neurons in the mesocorticolimbic pathway express Cav1.2 and Cav1.3 channels, which may regulate dopaminergic activity associated with reward behavior. Therefore, this study aimed to investigate the hypothesis that pre-administration of the LTCC blocker, isradipine can mitigate the effects of cocaine by modulating central glutamatergic transmission. For that, we administered isradipine at varying concentrations (1, 7.5, and 15 µg/µL) via intracerebroventricular injection in male Swiss mice. This pretreatment was carried out prior to subjecting animals to behavioral assessments to evaluate cocaine-induced locomotor sensitization and conditioned place preference (CPP). The results revealed that isradipine administered at a concentration of 1 µg/µL effectively attenuated both the sensitization and CPP induced by cocaine (15 mg/kg, via i. p.). Moreover, mice treated with 1 µg/µL of isradipine showed decreased presynaptic levels of glutamate and calcium in the cortex and hippocampus as compared to control mice following cocaine exposure. Notably, the gene expression of ionotropic glutamate receptors, AMPA, and NMDA, remained unchanged, as did the expression of Cav1.2 and Cav1.3 channels. Importantly, these findings suggest that LTCC blockage may inhibit behavioral responses to cocaine, most likely by decreasing glutamatergic input in areas related to addiction.


Subject(s)
Calcium Channel Blockers , Cocaine , Mice , Male , Animals , Calcium Channel Blockers/pharmacology , Isradipine/pharmacology , Glutamic Acid , Cocaine/pharmacology , Dopamine/metabolism
14.
Hypertension ; 81(4): 811-822, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38507511

ABSTRACT

BACKGROUND: The zona glomerulosa of the adrenal gland is responsible for the synthesis and release of the mineralocorticoid aldosterone. This steroid hormone regulates salt reabsorption in the kidney and blood pressure. The most important stimuli of aldosterone synthesis are the serum concentrations of angiotensin II and potassium. In response to these stimuli, voltage and intracellular calcium levels in the zona glomerulosa oscillate, providing the signal for aldosterone synthesis. It was proposed that the voltage-gated T-type calcium channel CaV3.2 is necessary for the generation of these oscillations. However, Cacna1h knock-out mice have normal plasma aldosterone levels, suggesting additional calcium entry pathways. METHODS: We used a combination of calcium imaging, patch clamp, and RNA sequencing to investigate calcium influx pathways in the murine zona glomerulosa. RESULTS: Cacna1h-/- glomerulosa cells still showed calcium oscillations with similar concentrations as wild-type mice. No calcium channels or transporters were upregulated to compensate for the loss of CaV3.2. The calcium oscillations observed were instead dependent on L-type voltage-gated calcium channels. Furthermore, we found that L-type channels can also partially compensate for an acute inhibition of CaV3.2 in wild-type mice. Only inhibition of both T- and L-type calcium channels abolished the increase of intracellular calcium caused by angiotensin II in wild-type. CONCLUSIONS: Our study demonstrates that T-type calcium channels are not strictly required to maintain glomerulosa calcium oscillations and aldosterone production. Pharmacological inhibition of T-type channels alone will likely not significantly impact aldosterone production in the long term.


Subject(s)
Calcium Channels, L-Type , Zona Glomerulosa , Mice , Animals , Zona Glomerulosa/metabolism , Calcium Channels, L-Type/metabolism , Calcium Channel Blockers/pharmacology , Aldosterone/metabolism , Calcium Signaling , Calcium/metabolism , Angiotensin II/pharmacology , Angiotensin II/metabolism
15.
Biomed Pharmacother ; 174: 116472, 2024 May.
Article in English | MEDLINE | ID: mdl-38531121

ABSTRACT

The Voltage-Gated Calcium Channel (VGCC) auxiliary subunit Cavα2δ-1 (CACNA2D1) is the target/receptor of gabapentinoids which are known therapeutics in epilepsy and neuropathic pain. Following damage to the peripheral sensory nervous system, Cavα2δ-1 is upregulated in dorsal root ganglion (DRG) neurons in several animal models of chronic neuropathic pain. Gabapentinoids, such as gabapentin and pregabalin, engage with Cavα2δ-1 via binding an arginine residue (R241) within an RRR motif located at the N-terminus of human Cavα2δ-1. A novel, next generation gabapentinoid, engineered not to penetrate the brain, was able to generate a strong analgesic response in Chronic Constriction Injury animal model of chronic neuropathic pain and showed binding specificity for Cavα2δ-1 versus the Cavα2δ-2 subunit. This novel non-brain penetrant gabapentinoid, binds to R241 and a novel binding site on Cavα2δ-1, which is located within the VGCC_α2 domain, identified as a lysine residue within an IKAK amino acid motif (K634). The overall whole cell current amplitudes were diminished by the compound, with these inhibitory effects being diminished in R241A mutant Cavα2δ-1 subunits. The functional effects occurred at lower concentrations than those needed for inhibition by gabapentin or pregabalin, which apparently bound the Cavα2δ-1 subunit only on the R241 and not on the K634 residue. Our work sets the stage for the identification and characterisation of novel compounds with therapeutic properties in neuropathic pain and possibly in other disorders and conditions which require engagement of the Cavα2δ-1 target.


Subject(s)
Calcium Channels, L-Type , Neuralgia , Neuralgia/drug therapy , Neuralgia/metabolism , Animals , Ligands , Humans , Male , Calcium Channels/metabolism , Calcium Channels/genetics , Gabapentin/pharmacology , Rats, Sprague-Dawley , Ganglia, Spinal/metabolism , Ganglia, Spinal/drug effects , Rats , Calcium Channel Blockers/pharmacology , Calcium Channels, N-Type/metabolism , Calcium Channels, N-Type/genetics , Analgesics/pharmacology , Disease Models, Animal , Pregabalin/pharmacology
17.
Exp Physiol ; 109(5): 779-790, 2024 May.
Article in English | MEDLINE | ID: mdl-38445814

ABSTRACT

Endothelial dysfunction develops with age and may precede cardiovascular disease. Animal data suggest that T-type calcium channels play an important role in endothelial function, but data from humans are lacking. This study included 15 healthy, sedentary, elderly males for a double blinded, randomized controlled trial. For 8 weeks, they were given 40 mg/day of either efonidipine (L- and T-type calcium channel blocker (CCB)) or nifedipine (L-type CCB). Vascular function was evaluated by graded femoral arterial infusions of acetylcholine (ACh; endothelium-dependent vasodilator) and sodium nitroprusside (endothelium-independent vasodilator) both with and without co-infusion of N-acetylcysteine (NAC; antioxidant). We measured leg blood flow and mean arterial pressure and calculated leg vascular conductance to evaluate the leg vascular responses. Despite no significant change in blood pressure in either group, we observed higher leg blood flow responses (Δ 0.43 ± 0.45 l/min, P = 0.006) and leg vascular conductance (Δ 5.38 ± 5.67 ml/min/mmHg, P = 0.005) to intra-arterial ACh after efonidipine, whereas there was no change in the nifedipine group, and no differences between groups. We found no upregulation of endothelial nitric oxide synthase in vastus lateralis muscle biopsies within or between groups. Smooth muscle cell responsiveness was unaltered by efonidipine or nifedipine. Intravenous co-infusion of NAC did not affect endothelium-dependent vasodilatation in either of the CCB groups. These results suggest that 8 weeks' inhibition of T- and L-type calcium channels augments endothelium-dependent vasodilatory function in healthy elderly males. Further studies are required to elucidate if T-type calcium channel inhibition can counteract endothelial dysfunction.


Subject(s)
Calcium Channel Blockers , Calcium Channels, T-Type , Endothelium, Vascular , Nifedipine , Nitrophenols , Humans , Male , Calcium Channels, T-Type/metabolism , Calcium Channels, T-Type/drug effects , Aged , Calcium Channel Blockers/pharmacology , Nifedipine/pharmacology , Pilot Projects , Double-Blind Method , Endothelium, Vascular/drug effects , Endothelium, Vascular/metabolism , Endothelium, Vascular/physiology , Dihydropyridines/pharmacology , Vasodilation/drug effects , Vasodilation/physiology , Vasodilator Agents/pharmacology , Blood Pressure/drug effects , Blood Pressure/physiology , Regional Blood Flow/drug effects , Regional Blood Flow/physiology , Organophosphorus Compounds/pharmacology , Acetylcholine/pharmacology , Leg/blood supply , Nitroprusside/pharmacology , Middle Aged
19.
Talanta ; 274: 125947, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38537353

ABSTRACT

Calcium channel blockers (CCB) of astrocytes can blockade the calcium ions entry through the voltage gated calcium channels (VGCC), and is widely used in the diseases related with VGCC of astrocytes. But many aspects of the interaction mechanisms between the CCB and VGCC of astrocytes still remain unclear due to the limited resolution of the approaches. Herein the effects of the nicardipine (a type of CCB) on VGCC of astrocytes were investigated at very high spatial, force and electrical resolution by multiple modes of Atomic Force Microscopy (AFM) directly. The results reveal that after the addition of nicardipine, the recognition signals of VGCC disappeared; the specific unbinding forces vanished; the conductivity of the astrocytes decreased (the current decreased about 2.9 pA and the capacitance was doubled); the surface potential of the astrocytes reduced about 14.2 mV. The results of electrical properties investigations are consistent with the simulation experiments. The relations between these biophysical and biochemical properties of VGCC have been discussed. All these demonstrate that the interactions between nicardipine and VGCC have been studied at nanometer spatial resolution, at picoNewton force resolution and very high electrical signal resolution (pA in current, pF in capacitance and 0.1 mV in surface potential) level. The approaches are considered to be high resolution and high sensitivity, and will be helpful and useful in the further investigations of the effects of other types of CCB on ion channels, and will also be helpful in the investigations of mechanisms and therapy of ion channelopathies.


Subject(s)
Astrocytes , Calcium Channel Blockers , Calcium Channels , Microscopy, Atomic Force , Nicardipine , Astrocytes/drug effects , Astrocytes/metabolism , Astrocytes/cytology , Nicardipine/pharmacology , Animals , Calcium Channels/metabolism , Calcium Channels/drug effects , Calcium Channel Blockers/pharmacology , Rats , Cells, Cultured
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