The pore-forming subunits of canonical voltage-gated sodium and calcium channels are encoded by four repeated domains of six-transmembrane (6TM) segments. We expressed and characterized a bacterial ion channel (NaChBac) from Bacillus halodurans that is encoded by one 6TM segment. The sequence, especially in the pore region, is similar to that of voltage-gated calcium channels. The expressed cha...

Venoms from various predatory species, such as fish hunting molluscs scorpions, snakes and arachnids contain a large spectrum of toxins that include blockers of voltage-gated calcium channels. These peptide blockers act by two principal manners - physical occlusion of the pore and prevention of activation gating. Many of the calcium channel-blocking peptides have evolved to tightly occupy their...

BACKGROUND The macrolide antibiotics clarithromycin and erythromycin may potentiate calcium-channel blockers by inhibiting cytochrome P450 isoenzyme 3A4. However, this potential drug interaction is widely underappreciated and its clinical consequences have not been well characterized. We explored the risk of hypotension or shock requiring hospital admission following the simultaneous use of cal...

aLaboratório de Meiofauna, Departamento de Zoologia, Centro de Ciências Biológicas – CCB, Universidade Federal de Pernambuco – UFPE, Av. Prof. Moraes Rego, 1235, CEP 50670-901, Recife, PE, Brazil bLaboratório de Ornitologia, Programa de Pós-graduação em Etnobiologia e Conservação da Natureza, Departamento de Biologia, Universidade Federal Rural de Pernambuco – UFRPE, Rua Dom Manuel de Medeiros,...

BACKGROUND AND OBJECTIVES A major obstacle to the successful use of chemotherapy in the treatment of leukemia and other cancers is the emergence of drug resistance. One of the most studied resistance mechanisms is mediated by P-glycoprotein, which can be modulated by calcium channel blockers. Here we investigated whether the Ca(2+) channel blockers verapamil and nifedipine are toxic alone and i...

Clinical trials have reported reduced cardiovascular events with certain antihypertensive agents at a rate that could not be predicted by changes in brachial arterial pressure alone. These findings may be explained, in part, by pleiotropic effects of these agents and modulation of central blood pressures. This review focuses on the mechanisms by which calcium channel blockers exert pleiotropic ...

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...

Subjects. Patients aged :<:: 60 years with sitting systolic blood pressure (BP) 160 219 mmHg and sitting diastolic BP< 95 mmHg during run-in phase. Methods and Results. Four thousand, six hundred and ninety-five patients were randomly assigned to active treatment (N = 2 398), i.e. nitrendipine, with the possible addition of enalapril and hydrochlorothiazide, or to matching placebos (N = 2 297)....

Objective: To explore the anti-inflammatory activity of calcium channel blockers. Material and Methods: The anti-inflammatory activity was determined by producing inflammation in rats of either sex. Acute inflammation was produced by injecting carrageenan, formalin and histamine in hindpaw of rats. For sub-acute inflammation the cotton pellets granuloma method was employed. Formaldehyde induced...

We have undertaken a detailed study of the mechanisms of maintenance of intracellular Ca2+ homeostasis in human polymorphonuclear neutrophils (PMN) and its implications for phagocytosis and IgG Fc receptor (FcR) signaling. When PMN were incubated in Ca2+free medium, cytoplasmic calcium concentration ([Ca"+Ii) was markedly depressed and intracellular stores were depleted of calcium. [Ca2+Ii n th...