An efficient and expeditious catalyst-free procedure was developed for the one- pot synthesis of 1, 4-dihydropyridine derivatives via the three-component reaction of various aldehydes, ethyl acetoacetate, and ammonium acetate in PEG-400. The reaction was carried out at 110°С and the products were obtained in good to high yields.

ZrP2O7 nanoparticles (NPs) as an efficient catalyst have been used for the preparation of 1,6-diamino-2- oxo-4-phenyl-1,2-dihydropyridine-3,5-dicarbonitrile derivatives via one-pot coupling of hyrazine hydrate, ethyl cyanoacetate, malononitrile and aromatic aldehydes under reflux conditions in ethanol. Using this method we obtained low reaction times, easy isolation of the targeted molecules, e...

The dihydropyridine calcium channel blocker, nitrendipine, was studied for its effects on the sodium current of single cultured ventricular cells from neonatal rats. The patch-clamp method of recording whole cell currents was used, and sodium currents were isolated by suppressing potassium and calcium currents. Potassium currents were blocked by replacing potassium with cesium in the internal a...

The influx of Ca ions into the presynaptic nerve terminal through ion channels is a key link between the action potential and the release of chemical transmitters. It is not clear, however, which types of Ca channel are involved in neurosecretion at vertebrate synapses. In particular, there is disagreement as to whether these channels are sensitive to dihydropyridine blockers, characteristic of...

Skeletal and cardiac dihydropyridine receptors function both as voltage-dependent L-type calcium channels (L-channels) and as critical proteins that trigger calcium release from the sarcoplasmic reticulum in muscle. In spite of these similarities, skeletal L-channels exhibit a markedly slower activation rate than cardiac L-channels. We investigated the mechanisms underlying this difference by c...

The multicomponent reaction of 2-nitroacetophenone (or nitroacetone), acetaldehyde diethyl acetal, ?-dicarbonyl compound, and ammonium acetate in an acetic acid solution allowed the acquisition previously undescribed 4-methyl-substituted derivatives 5-nitro-1,4-dihydropyridine satisfactory yields. oxidation obtained resulted corresponding 2,4-dimethyl-5-nitropyridines. In addition, for first ti...

We investigated the mechanism of interaction of individual L-type channel amino acid residues with dihydropyridines within a dihydropyridine-sensitive a1A subunit (a1ADHP). Mutation of individual residues in repeat III and expression in Xenopus oocytes revealed that Thr is not required for dihydropyridine interaction but that bulky side chains (tyrosine, phenylalanine) in this position sterical...

the 1,4-dihydropyridine (dhp) derivatives are a known class of calcium channel blockers. some derivatives of dhp showed significant cytotoxicity. it was shown that this effect may not be the result of interaction with ca2+ channels. in this study, we performed an investigation about the intrinsic cytotoxicity of some derivatives of dhp containing nitroimidazole moiety on their c4 position on fo...

The subcellular distribution of the 1,4-dihydropyridine receptor was determined in rabbit skeletal muscle in situ by immunofluorescence and immunoelectron microscopy. Longitudinal and transverse cryosections (5-8 microns) of rabbit gracilis muscle were labeled with monoclonal antibodies specific against either the alpha 1-subunit (170,000-D polypeptide) or the beta-subunit (52,000-D polypeptide...