the goal of this study was to determine the effects of the l-type calcium channel blockers verapamil and diltiazem on the currents of voltage-gated potassium channel (fkv1.4δn), an n-terminal-deleted mutant of the ferret kv1.4 potassium channel. measurements were made using a two electrode voltage clamp technique with channels expressed stably in xenopus oocytes. the fkv1.4δn currents displayed...

The goal of these studies was to determine whether different calcium channel antagonists affect glucose transport in a neuronal cell line. Rat pheochromocytoma (PC-12) cells were treated with L-, T-, and N-type calcium channel antagonists before measurement of accumulation of 2-[(3)H]deoxyglucose (2-[(3)H]DG). The L-type channel antagonists nimodipine, nifedipine, verapamil, and diltiazem all i...

The goal of this study was to determine the effects of the L-type calcium channel blockers verapamil and diltiazem on the currents of voltage-gated potassium channel (fKv1.4ΔN), an N-terminal-deleted mutant of the ferret Kv1.4 potassium channel. Measurements were made using a two electrode voltage clamp technique with channels expressed stably in Xenopus oocytes. The fKv1.4ΔN currents displayed...

Channel activity of the calcium release channel from skeletal muscle, ryanodine receptor type 1, was measured in the presence and absence of protamine sulfate on the cytoplasmic side of the channel. Single-channel activity was measured after incorporating channels into planar lipid bilayers. Optimally and suboptimally calcium-activated calcium release channels were inactivated by the applicatio...

The L type calcium channel agonist (+/-)Bay K 8644 has been reported to cause characteristic motor abnormalities in adult mice. The current study shows that administration of this drug can also cause the unusual phenomenon of self-injurious biting, particularly when given to young mice. Self-biting is provoked by injecting small quantities of (+/-)Bay K 8644 directly into the lateral ventricle ...

The aim of the present study was to examine the effects of calcium channel protein on ovarian cancer cells. The expression of calcium channel protein in normal ovarian cells and ovarian cancer cells was detected by fluorescence quantitative PCR. Subsequently, the ovarian cancer cells were added to calcium channel protein activator media at various concentrations of 0, 1, 4, 8, 12, 16 and 20 mmo...

We present the cloning and characterization of two novel calcium-activated potassium channel beta subunits, hKCNMB3 and hKCNMB4, that are enriched in the testis and brain, respectively. We compare and contrast the steady state and kinetic properties of these beta subunits with the previously cloned mouse beta1 (mKCNMB1) and the human beta2 subunit (hKCNMB2). Once inactivation is removed, we fin...

BACKGROUND Physicians' financial relationships with the pharmaceutical industry are controversial because such relationships may pose a conflict of interest. It is unknown to what extent industry support of medical education and research influences the opinions and behavior of clinicians and researchers. The recent debate over the safety of calcium-channel antagonists provided an opportunity to...

Calcium channel blockers are widely used antihypertensives. Mineralocorticoid receptor antagonists are also used to treat hypertension and heart failure. We report here that a number of widely used dihydropyridine class calcium channel blockers are able to inhibit aldosterone-induced activation of mineralocorticoid receptor. These dihydropyridines varied in the extent of their effect on mineral...

39 The quantitative relationship between presynaptic calcium influx and transmitter 40 release critically depends on the spatial coupling of presynaptic calcium channels to 41 synaptic vesicles. When there is a close association between calcium channels and 42 synaptic vesicles, the flux through a single open calcium channel may be sufficient to 43 trigger transmitter release. With increasing s...