We show that peptide fragments of the dihydropyridine receptor II-III loop alter cardiac RyR (ryanodine receptor) channel activity in a cytoplasmic Ca2+-dependent manner. The peptides were AC (Thr-793-Ala-812 of the cardiac dihydropyridine receptor), AS (Thr-671-Leu-690 of the skeletal dihydropyridine receptor), and a modified AS peptide [AS(D-R18)], with an extended helical structure. The pept...

To evaluate the effects of calcium antagonists on sympathetic activity in hypertensive patients, a MEDLINE search for English language articles published between 1975 and May 1996 using the terms calcium antagonists, sympathetic nervous system, and catecholamines was conducted. Clinical studies only reporting the effects of calcium antagonists on blood pressure, heart rate, and plasma norepinep...

The binding of dihydropyridine (PN200-110) to skeletal muscle microsomes (which were 84% sealed inside-out vesicles) was not influenced by the addition of calcium or magnesium nor by addition of their chelators (EDTA or EGTA) unless the vesicles were pretreated with the calcium-magnesium ionophore A23187 and EDTA to remove entrapped cations. Separation of inside-out vesicles from right-side-out...

BACKGROUND Nilaparvata lugens, a major pest in rice-growing areas, is extremely difficult to manage. Neonicotinoids have increasingly been used in crop protection and animal health care against N. lugens. To discover new bioactive molecules and pesticides, we combined the active structure of cyanoacrylates, aromatic aldehydes, and substituted pyridyl (thiazolyl) methyl-2-substituted-methylidene...

mice were rendered tolerant and dependent to morphine by subcutaneous injection of morphine over a period of 5 days. the effects of acute and chronic administration of dihydropyridine calcium channel antagonist nifedipine on the development of tolerance and naloxone-precipitated morphine withdrawal signs were investigated. a single injection of nifedipine proved to be effective in inhibiting so...

An efficient one pot synthesis of dihydropyridine derivatives employing the transient zwitterions generated from aniline and allenoates is described.

Previous studies have demonstrated multiple components of whole-cell calcium currents in hypoglossal motoneurons (HMs); HMs possess a low-voltage-activated (LVA) current and three types of high-voltage-activated (HVA) calcium currents based on sensitivity to omega-Aga IVA, omega-Conotoxin GVIA (omega-CgTx) and dihydropyridine analogs (DHPs). In the present study, we recorded single-calcium chan...

Epilepsy is a chronic disorder of the brain affecting around 50 million people in the world.Up to 30% of epileptic patients do not respond to available drugs and medical therapies. In thispaper, anticonvulsant screening of 10 synthesized new derivatives of 1, 4-dihydropyridine-3,5-dicarboxamides was performed.Anticonvulsant activity was evaluated by intravenous and intraperitoneal pentylenetetr...

Hantzsch condensation of two equivalents of methyl-3-aminocrotonate with (m- and p)-methoxybenzaldehyde afforded the expected products 2,6-dimethyl-3,5-dimethoxycarbonyl-4-(m-methoxyphenyl)-1,4-dihydropyridine and 2,6-dimethyl-3,5-dimethoxycarbonyl-4-(p-methoxyphenyl)-1,4-dihydropyridine, whereas o-methoxy-benzaldehyde produced mainly 1-amino-2-methoxycarbonyl-3,5-bis(o-methoxy-phenyl)-4-oxa-cy...