The purpose of this study was to determine the mechanisms by which organic calcium channel blockers inhibit cerebral vasoconstriction. Isolated bovine middle cerebral arteries were cut into rings to measure contractility or into strips to measure radioactive calcium (45Ca) influx and efflux. Calcium channel blockers (10(-5) M verapamil or 3.3 X 10(-7) M nifedipine) and calcium-deficient solutio...

BACKGROUND The prognostic significance of heart rate (HR) and its relationship with beta-blocker use are controversial and have never been evaluated in resistant hypertension. METHODS In a prospective study, 528 patients with resistant hypertension had HR measured on clinical examination, electrocardiography (ECG), and during ambulatory blood pressure monitoring. Primary endpoints were a comp...

BACKGROUND β-blockers have little effectiveness in preventing vasovagal syncope in unselected populations, but they might be effective in older patients. We determined whether β-blockers prevent vasovagal syncope in an age-related fashion. METHODS AND RESULTS Two populations were studied. A proportional hazards analysis was performed on an observational cohort study of 153 patients with vasov...

the high performance liquid chromatography (hplc) enantioseparation of four β-blocking agents metoprolol, bisoprolol, propranolol and atenolol was performed on amylose tris-(3,5-dimethylphenylcarbamate) chiral stationary phase using n-hexane-ethanol-diethylamine (dea) as the mobile phase and related chiral recognition mechanisms were discussed. enantiomeric separation of the fourβ-blockers was ...

Entorhinal cortex (EC) is one of the first Entorhinal cortex (EC) is one of the first cerebral regions affected in Alzheimer’sdisease (AD). The pathology propagates to neighboring cerebral regions through a prion-likemechanism. In AD, intracellular calcium dyshomeostasis is associated with endoplasmicreticulum (ER) stress. This study was designed to examine hippocampal ER stre...

The daily changes in cellular shape observed in growth-synchronized cultures of Euglena gracilis Klebs strain Z, were altered by exposure to Ca2+ channel agonists and antagonists. The response of the cells to these pharmacological agents depended, in part, on the time in the growth cycle that the cells were exposed. The Ca2+ channel blockers verapamil and nifedipine and the intracellular Ca2+ a...

Systemic sclerosis (systemic scleroderma) is a chronic connective tissue disease of unknown etiology that causes widespread microvascular damage and excessive deposition of collagen in the skin and internal organs. Raynaud phenomenon and scleroderma (hardening of the skin) are hallmarks of the disease. The typical patient is a young or middle-age woman with a history of Raynaud phenomenon who p...