Target: L-type voltage-dependent Ca2+ channel, specifically the α1C subunit isoforms: α1C-a (cardiac isoform) and α1C-b (vascular isoform). For α1C-b, Kd (resting state) = 0.56 ± 0.10 nM; for α1C-a, Kd (resting state) = 2.1 ± 0.5 nM [1]
Inactivated state binding: KI for α1C-b = 0.08 ± 0.02 nM; for α1C-a = 0.16 ± 0.03 nM [1]

In vitro activity: Nisoldipine is a potent blocker of L-type calcium channels. Nisoldipine binds directly to inactive calcium channels stabilizing their inactive conformation Similar to other DHP CCBs. Nisoldipine displays selectivity for arterial smooth muscle cells due to great number of inactive channels and the α1 subunit of the channel. Nisoldipine is about 30 times less selective for delayed-rectifier K+ channels than for L-type Ca2+ channels, which inhibits IKr (rapidly activating delayed-rectifier K+ current) with IC50 of 23 μM, and IKs (slowly activating delayed-rectifier K+ current)with IC50 of 40 μM in guinea-pig ventricular myocytes. Nisoldipine also displays antioxidant potency with IC50 of 28.2 μM both before and after the addition of active oxygen. This is tested by means of rat myocardial membrane lipid peroxidation with a nonenzymatic active oxygen-generating system (DHF/FeC13-ADP).
Kinase Assay: CHO cells expressing the subunit of the voltage-dependent L-type Ca2+ channel are cultrured in medium without serum in the presence of different concentrations of Nisoldipine. Then Ca2+ channel current elicited from a holding potential of -100 mV or -50 mV is recorded at room temperature with the whole-cell configuration of the patch-clamp method using the List EPC-7 patch-clamp amplifer and pClamp software. The concentration of competitor inhibiting 50% of the specific binding represents IC50.
Cell Assay: The myocytes are bathed in normal Tyrodes solution, held at -80 mV, and depolarised after 200-ms prepulses (-40mV) to more positive potentials for 500 ms at 0.1 Hz, tail currents are recorded on repolarisations to -40mV. The myocytes are exposed to 10-100 mM Nisoldipine for 8-10 minutes. Then the whole-cell membrane currents are recorded using an EPC-7 amplifier.

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In Vitro: Nisoldipine inhibited Ba2+ current (Iα1) through recombinant α1C-a and α1C-b subunits expressed in CHO cells in a concentration-dependent manner. At holding potential -100 mV, the dissociation constant (K-100mV) was 2.1 ± 0.5 nM for α1C-a and 0.56 ± 0.10 nM for α1C-b, showing 4-fold higher potency on α1C-b. At holding potential -50 mV, K-50mV was 0.33 ± 0.07 nM for α1C-a and 0.15 ± 0.03 nM for α1C-b, showing 2-fold higher potency on α1C-b. Voltage-dependent increase in potency (K-100mV/K-50mV ratio) was 6 for α1C-a and 3.7 for α1C-b. Nisoldipine (3 nM) shifted the steady-state inactivation curve to more negative potentials: V0.5 changed from -45.5±0.3 mV to -63.4±0.9 mV in α1C-a cells, and from -44.5±1.2 mV to -69.6±1.4 mV in α1C-b cells. Calculated KR and KI from inactivation shift: for α1C-a, KR=4.9±1.8 nM, KI=0.25±0.01 nM; for α1C-b, KR=1.2±0.3 nM, KI=0.07±0.02 nM. Nisoldipine did not alter the position of the current-voltage relationship maximum or activation threshold in either isoform [1]

Nisoldipine decreases arterial smooth muscle contractility and subsequent vasoconstriction by inhibiting the influx of calcium ions through L-type calcium channels. This results in vasodilation and an overall decrease in blood pressure, based on which Nisoldipine is used to treat mild to moderate essential hypertension, chronic stable angina and Prinzmetals variant angina. Nisoldipine shows some ability in patients with Timothy syndrome having Cav1.2 missense mutation G406R with IC50 of 267 nM, which is helpful to treat TS.

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Enzyme Assay: [3H]-(+)-PN200-110 binding displacement experiments were performed in intact CHO cells expressing α1C-a or α1C-b subunits. Cells were incubated in medium containing 5 mM KCl (physiological) or 50 mM KCl (depolarizing) for 90 min at 37°C with [3H]-(+)-PN200-110 (75 Ci/mmol) and various concentrations of unlabeled competitor including Nisoldipine. Non-specific binding was determined in the presence of 1 µM nifedipine. The reaction was stopped by washing cells with a solution containing 0.9% NaCl, 5% DMSO, and 1% bovine serum albumin. Cells were solubilized in 0.2% sodium dodecylsulfate and radioactivity counted by liquid scintillation. Protein content was determined according to Lowry method. Inhibition constants (Kinh) were calculated from displacement curves. For Nisoldipine, in 5 mM KCl: Kinh = 1.3 ± 0.2 nM for α1C-a and 0.20 ± 0.01 nM for α1C-b; in 50 mM KCl: Kinh = 0.28 ± 0.04 nM for α1C-a and 0.07 ± 0.01 nM for α1C-b [1]

Cell Assay: Whole-cell patch-clamp recordings were performed at room temperature. CHO cells transfected with α1C-a or α1C-b cDNAs were superfused with bath solution containing (mM): NaCl 120, BaCl2 10, MgCl2 1.2, glucose 10, HEPES 10, pH 7.4 with NaOH. Patch pipettes (3-5 MΩ) were filled with internal solution containing (mM): NaCl 120, MgCl2 4, Na2ATP 5, glucose 10, HEPES 10, EGTA 3, pH 7.2 with NaOH. Currents were elicited by 25 ms depolarizing pulses to 0 mV from holding potentials of -100 mV or -50 mV, applied every 10 s. The effect of Nisoldipine was assessed by measuring current inhibition at various concentrations. Concentration-response curves were fitted to equation I(% control)=100K/(K+[A]). Steady-state inactivation was measured using 90 s conditioning potentials from -100 to -10 mV. The voltage of half-inactivation (V0.5) and slope factor (k) were fitted to Boltzmann equation. The shift in V0.5 in the presence of Nisoldipine (3 nM) was used to calculate KR and KI [1]

Dissolved in DMSO and diluted in saline; 10 mg/kg; oral gavage Male Wistar rats with chronic intragastric ethanol exposure

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Absorption, Distribution and Excretion
Nisodipine is well absorbed in the systemic circulation, with 87% of the radiolabeled drug recovered from urine and feces. The absolute bioavailability of nisodipine is approximately 5%. Although 60-80% of the oral dose is excreted in the urine, only trace amounts of the parent nisodipine are detected in urine. Metabolism/Metabolites Nisodipine undergoes first-pass metabolism in the intestinal wall, with the rate of metabolism decreasing gradually from the proximal to the distal end of the intestine. Nisodipine is actively metabolized, and five major urinary metabolites have been identified. The main biotransformation pathway appears to be the hydroxylation of isobutyl ester. The hydroxylated derivative of the side chain, with a plasma concentration approximately equal to that of the parent compound, appears to be the only active metabolite, with an activity approximately 10% that of the parent compound. Cytochrome P450 enzymes are thought to play an important role in the metabolism of nisodipine. The specific isoenzyme system responsible for its metabolism has not yet been identified, but other dihydropyridine drugs are metabolized by cytochrome P450 IIIA4. Known metabolites of nisodipine include 2,6-dimethyl-5-(2-methylpropoxycarbonyl)-4-(2-nitrophenyl)-1,4-dihydropyridine-3-carboxylic acid, dehydronisodipine, and 5-O-(1-hydroxy-2-methylpropyl)-3-O-methyl-2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid ester. Biological half-life: 7–12 hours

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Effects During Pregnancy and Lactation
◉ Overview of Medication Use During Lactation
Since there is currently no information regarding the use of nisodipine during lactation, alternative medications are recommended. ◉ Effects on Breastfed Infants
As of the revision date, no relevant published information was found. ◉ Effects on Lactation and Breast Milk
As of the revision date, no relevant published information was found.

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Protein Binding Rate
99%

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Br J Pharmacol.1998;125(5):1005-12;Br J Pharmacol.2003;140(5):863-70;Hepatology.1996;24(2):391-7.

Methyl 2-Methylpropyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid methyl ester is a dihydropyridine compound with the structure 1,4-dihydropyridine, substituted with methyl groups at positions 2 and 6, a methoxycarbonyl group at position 3, an o-nitrophenyl group at position 4, and an isobutyryloxycarbonyl group at position 5. The racemic form of this compound is a calcium channel blocker used to treat hypertension and angina. It is a C-nitro compound belonging to the diester, dihydropyridine, and methyl ester class of compounds, and is also a member of the dicarboxylic acid and its O-substituted derivatives family. Nisodipine is a 1,4-dihydropyridine calcium channel blocker. It primarily acts on vascular smooth muscle cells, exerting its effect through stabilizing the inactive conformation of voltage-gated L-type calcium channels. Nisodipine inhibits the influx of calcium ions into smooth muscle cells, preventing calcium-dependent smooth muscle contraction and subsequent vasoconstriction. Nisodipine can be used alone or in combination with other drugs to treat hypertension. Nisodipine is a dihydropyridine calcium channel blocker. Its mechanism of action is as a calcium channel antagonist. The physiological effect of nisodipine is to lower blood pressure. Nisodipine is a second-generation calcium channel blocker and a commonly used antihypertensive drug. Nisodipine treatment is associated with a low incidence of elevated serum enzymes, but no direct association has been found with clinically significant cases of acute liver injury. Nisodipine is a dihydropyridine calcium channel blocker. Nisodipine inhibits the transmembrane inflow of extracellular calcium ions into myocardial and vascular smooth muscle cells, leading to dilation of major coronary and systemic arteries and a decrease in myocardial contractility. This drug also inhibits the drug efflux pump P-glycoprotein, which is overexpressed in some multidrug-resistant tumors; therefore, nisodipine may enhance the efficacy of certain antitumor drugs. (NCI04) A dihydropyridine calcium channel antagonist with potent arterial vasodilatory and antihypertensive effects. It is also effective in patients with heart failure and angina. Indications Nisodipine is used to treat hypertension. It can be used alone or in combination with other antihypertensive drugs. Mechanism of Action Nisodipine inhibits the influx of extracellular calcium ions across the smooth muscle cell membranes of myocardial and vascular tissues by altering calcium channel structure, inhibiting ion-gating mechanisms, and/or interfering with the release of calcium ions from the sarcoplasmic reticulum. The decrease in intracellular calcium ion concentration inhibits the contractile process of myocardial smooth muscle cells, leading to dilation of coronary and systemic arteries, increasing oxygen supply to myocardial tissue, reducing total peripheral resistance, lowering systemic blood pressure, and reducing afterload. Pharmacodynamics Nisodipine is a dihydropyridine calcium channel blocker that can be used alone or in combination with angiotensin-converting enzyme inhibitors to treat hypertension, chronic stable angina, and prinzmetal angina. Nisodipine is similar to other peripheral vasodilators. Nisodipine may inhibit the influx of extracellular calcium ions across the membranes of cardiomyocytes and vascular smooth muscle cells by altering ion channel morphology, inhibiting ion gating mechanisms, and/or interfering with calcium ion release from the sarcoplasmic reticulum. The decrease in intracellular calcium ion concentration inhibits the contractile process of myocardial smooth muscle cells, leading to coronary and systemic arterial dilation, increased oxygen supply to myocardial tissue, reduced total peripheral resistance, decreased systemic blood pressure, and reduced afterload.

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Additional Info: Nisoldipine is a neutral dihydropyridine Ca2+ channel blocker with high vascular versus cardiac selectivity. In functional studies, the heart/vessel IC50 ratio for nisoldipine is about 1000, making it the most vascular-selective DHP among those tested. The higher affinity of Nisoldipine for the α1C-b (vascular) isoform compared to α1C-a (cardiac) isoform (4-7 fold at hyperpolarized potentials) may contribute to its tissue selectivity, but the ratio (about 7) is smaller than the functional selectivity ratio (1000). The difference in resting membrane potentials between cardiac and vascular cells (more negative in cardiac) amplifies the apparent selectivity: comparing inhibition at -100 mV in α1C-a cells with inhibition at -50 mV in α1C-b cells gives a potency ratio of about 15 for Nisoldipine, still lower than functional data. Thus, additional factors such as binding kinetics, voltage-dependence, and auxiliary subunits are involved in its tissue selectivity [1]

C20H24N2O6

388.4144

388.163

63675-72-9

Nisoldipine-d6;1285910-03-3;Nisoldipine-d4;1219795-47-7;Nisoldipine-d7;1189718-34-0

4499

Light yellow to yellow solid powder

1.2±0.1 g/cm3

505.8±50.0 °C at 760 mmHg

147-148°C

259.7±30.1 °C

0.0±1.3 mmHg at 25°C

1.544

3.3

1

7

7

28

704

0

O(C([H])([H])C([H])(C([H])([H])[H])C([H])([H])[H])C(C1=C(C([H])([H])[H])N([H])C(C([H])([H])[H])=C(C(=O)OC([H])([H])[H])C1([H])C1=C([H])C([H])=C([H])C([H])=C1[N+](=O)[O-])=O

VKQFCGNPDRICFG-UHFFFAOYSA-N

InChI=1S/C20H24N2O6/c1-11(2)10-28-20(24)17-13(4)21-12(3)16(19(23)27-5)18(17)14-8-6-7-9-15(14)22(25)26/h6-9,11,18,21H,10H2,1-5H3

3-isobutyl 5-methyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2.5 mg/mL (6.44 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (6.44 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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 (Please use freshly prepared in vivo formulations for optimal results.)