Dihydropyridine-sensitive calcium channels can be strongly modulated by cAMP-dependent phosphorylation. This modulation takes the form of increased channel availability in cardiac myocytes (for review, see McDonald et al., 1994) and has been suggested to be essential for voltage-dependent facilitation in adrenal chromaffin cells (Artalejo et al., 1992) and skeletal muscle (Sculptoreanu et al., ...

BACKGROUND AND PURPOSE Hypertension has been associated with Parkinson's disease (PD), but data on antihypertensive drugs and PD are inconclusive. We aim to evaluate antihypertensive drugs for an association with PD in hypertensive patients. METHODS Hypertensive patients who were free of PD, dementia and stroke were recruited from 2005-2006 using Taiwan National Health Insurance Database. We ...

Breast cancer resistance protein (BCRP, ABCG2) is a recently identified member of the ATP-binding cassette family of cell surface transport proteins. This study was conducted to investigate the effect of a series of newly synthesized 1,4-dihydropyridines and pyridines, designed as potent P-glycoprotein inhibitors, on BCRP-mediated drug efflux both in vitro and in vivo. The effects of 25 synthes...

PURPOSE Retinal photoreceptor cells are tonically depolarized in darkness. Ca2+ influx in darkness plays a critical role in the regulation of neurotransmitter release and melatonin synthesis in these sensory cells. The purpose of the present study was to examine the dynamic changes of intracellular Ca2+ concentrations ([Ca2+]in ) in response to a tonic depolarizing stimulus and to determine the...

Endothelin is a potent mammalian vasoconstrictive peptide with structural homology to cation channel-binding insect toxins. We tested the proposal that this peptide directly activates dihydropyridine-sensitive Ca2+ channels in cultured vascular smooth muscle (VSM) cells. First, we found that cell Ca2+ can be altered in VSM by activation of voltage-operated Ca2+ channels. KCl-induced depolarizat...

Increased ligand binding to dihydropyridine receptors in the central nervous system after chronic ethanol consumption is thought to contribute to the withdrawal syndrome. Previous studies demonstrated such changes when the binding was measured in vitro, which, as the receptors are voltage-sensitive, may not accurately reflect the binding in vivo. In the present study, dihydropyridine binding wa...