| Sandmann S, Unger T |
L- and T-type calcium channel blockade - the efficacy of the calcium channel antagonist mibefradil
Journal of Clinical and Basic Cardiology 1999; 2 (2): 187-201
PDF Summary Figures
| Figure |
| |
|
|
Kalziumkanal - Alpha-1-Einheit
Figure 1: Schematic representation of the α1 unit of the calcium channel with its structural composition of subunits I-IV and segments S1-S6, and the functional importance of the several components
Keywords: alpha-1-unit,
calcium channel,
Kalziumkanal,
Schema
|
| |
| |
|
|
L-Typ-Kalziumkanal - Medikamenteninteraktion
Figure 2: Schematic overview of the drug interaction sites of the CCA (dihydropyridines, diltiazem, verapamil, fantofarone, mibefradil) with the L-type calcium channel
Keywords: Dihydropyridin,
dihydropyridines,
Diltiazem,
Diltiazem,
Fantofaron,
fantofarone,
L-Typ-Kalziumkanal,
L-type calcium channel,
mibefradil,
mibefradil,
Schema,
Verapamil,
Verapamil
|
| |
| |
|
|
Kalziumkanal - Mibefradil
Figure 3A-C: Effects of 1 micromol/l mibefradil on T-type (A), L-type (B), and composite (C) Ba2+ current (IBa). (o conforms control group, black square conforms 1 microM mibefradil treated group). A: T-type IBa (VT= -20 mV from VH= -80 mV) was 80 % inhibited after 5 minutes by 1 micromol/l mibefradil. B: L-type IBa (VT= +20 mV from VH= -30 mV) was reduced by only 28 % after 8 minutes in 1 micromol/l mibefradil. C: The T-type peak and the same 28 % of L-type IBa as in B were blocked at 5 minutes by 1 micromol/l mibefradil (VT= +20 mV from VH= -80 mV). All tracings are from the same vascular muscle cell.
Keywords: Diagramm,
L-Typ-Kalziumkanal,
L-type calcium channel,
mibefradil,
mibefradil,
T-Typ-Kalziumkanal,
T-type calcium channel
|
| |
| |
|
|
Kalziumkanal - Mibefradil
Figure 4: Concentration-response curve for the action of mibefradil on vascular muscle Ca2+ currents shows that the actions are more efficacious on T-type currents (T, black triangle, peak up). L indicates L-type currents (black triangle, peak down). Black square indicates L- and T-type currents. These percent inhibitions are based on reductions of the Ba2+ current (IBa) as shown in figure 3, corresponding T to figure 3A, L to figure 3B, and L and T to figure 3C. Data represent mean +/- SEM for 6 to 16 cells at each concentration.
Keywords: Diagramm,
L-Typ-Kalziumkanal,
L-type calcium channel,
mibefradil,
mibefradil,
T-Typ-Kalziumkanal,
T-type calcium channel
|
| |
| |
|
|
Kalziumkanal - Mibefradil
Figure 5: Left panel: Inhibition of volume-activated Cl- currents by mibefradil. a: Activation of the volume-sensitive Cl- current ICl,vol by challenging the cell with a 27 % hypotonic solution. Mibefradil induced a fast and reversible block of ICl,vol. b: At the times indicated, I-V curves were depicted. Reversal potential was approximately at the expected ECl= -16 mV. c: Concentrationresponse curve of the inhibitory action of mibefradil on ICl,vol. Right panel: High-affinity block of Ca2+ activated Cl- channels by mibefradil. a: A CPAE cell was loaded with a Ca2+-solution buffered at 500 nM after breaking the membrane. Elevation of [Ca2+]i activated a Cl- current ICl,Ca. This current was probed by application of voltage ramps. From these ramps, the current can be measured at any potential. Shown is the current activation at +100 mV. Application of 10 microM mibefradil induced a fast and reversible block of ICl,Ca. b: At the times indicated in A, I-V curves were depicted; 1) shows the fully activated Cl- current, 2) the blocked current after application of mibefradil. c: Concentration-response curve of the inhibitory action of mibefradil.
Keywords: calcium channel,
Diagramm,
Kalziumkanal,
mibefradil,
mibefradil
|
| |
| |
|
|
Kalziumkanal - Mibefradil
Figure 6: Inhibition of proliferation of CPAE cells by mibefradil. Cells were seeded in the absence (sqaure, control) and the presence of (circle) 1 microM, (triangle, peak up) 10 micorM and (triangle, peak down) 100 microM mibefradil. Inhibition of proliferation was significant at all concentrations. At 100 microM no living cells were present, at 10 microM adhesive cells could still be counted indicating true antiproliferative effects. Plotted are mean +/- SEM (vertical lines) at each day after seeding.
Keywords: calcium channel,
Diagramm,
Kalziumkanal,
mibefradil,
mibefradil
|
| |
| |
|
|
Kalziumkanal - Mibefradil
Figure 7: Effects of verapamil (1 mg/kg i.v.) and mibefradil (3 mg/kg i.v.) on coronary blood flow (CBF) in dogs compared to placebo treated controls. CBF was measured with radioactive microspheres before and 10 min after initiation of drug treatment. Mean +/- SEM, * p<0.05 versus before therapy
Keywords: calcium channel,
coronary blood flow,
Diagramm,
Kalziumkanal,
koronarer Blutfluss,
mibefradil,
mibefradil,
Verapamil,
Verapamil
|
| |
| |
|
|
Kalziumkanal - Mibefradil
Figure 8A-B: Cumulative concentration-response curves for the effects of mibefradil, verapamil, and nifedipine on force of contraction in isolated, electrically driven human left ventricular papillary muscle strips. Original records (A) of isometric force of contraction after application of mibefradil (upper) and nifedipine (lower) and a summary of the results (B) are shown. Ordinate in B, force of
contraction in percentage of predrug value. Abscissa in B, concentration of drug (in microM). Number of strips is shown in brackets.
Keywords: calcium channel,
contraction force,
Diagramm,
Diltiazem,
Diltiazem,
Felodipin,
felodipine,
Isradipin,
isradipine,
Kalziumkanal,
Kontraktionskraft,
mibefradil,
mibefradil,
Nifedipin,
nifedipine,
Nitrendipin,
nitrendipine,
Verapamil,
Verapamil
|
| |
| |
|
|
Kalziumkanal - Mibefradil
Figure 9: Infarct size is given as percentage of left ventricular circumference (%) 6 weeks after induction of myocardial infarction (MI) in rats. Indicated are animals subjected to control MI animals (placebo, black column) and mibefradil-treated animals (10 mg/kg/d p.o.) started at different time points before and after induction of MI (striped columns, 7 d pre, 3 h post, 24 h post, 3 d post, 7 d post). Data represent mean +/- SEM, n = 12-15; * significant versus control MI (p < 0.05).
Keywords: calcium channel,
Diagramm,
infarct size,
Infarktgröße,
Kalziumkanal,
left ventricle,
linker Ventrikel,
mibefradil,
mibefradil
|
| |
| |
|
|
Kalziumkanal - Mibefradil
Figure 10: Cumulative percent survival of rats with chronic heart failure, either untreated (circle, n = 68) or treated with mibefradil (15 mg/kg/d, n = 59, white triangle) or cilazapril (10 mg/kg/d, n = 59, black triangle)
Keywords: calcium channel,
cilazapril,
cilazapril,
heart failure,
Herzinsuffizienz,
Kalziumkanal,
mibefradil,
mibefradil,
survival,
Überleben
|
| |
| |
|
|
Kalziumkanal - Mibefradil
Figure 11: Time courses of blood pressure, heart rate, PQ time, and change of cardiac output on day 1 (left panel) and day 8 (right panel) in patients with hypertension after oral administration of mibefradil given once daily as drinking solution (white circle indicates placebo (PL), triangle indicates 50 mg/kg, black circle indicates 150 mg/kg, square indicates 200 mg/kg mibefradil). Data are shown as mean +/- SEM.
Keywords: blood pressure,
Blutdruck,
calcium channel,
cardiac output,
cardiac output,
Diagramm,
heart rate,
Herzfrequenz,
Kalziumkanal,
mibefradil,
mibefradil,
PQ-time,
PQ-Zeit
|
| |
| |
|
|
Kalziumkanal - Mibefradil
Figure 12: Left panel: Maximal ST-segment depression in mV before (open bars) and 2 hours after (hatched bars) intake of placebo or 50, 100, or 200 mg/kg mibefradil; * p < 0.05. Right panel: Mean exercise duration in minutes before (open bars) and 2 hours after (hatched bars) intake of placebo or 50, 100, or 200 mg/kg mibefradil; * p < 0.05.
Keywords: Belastung,
calcium channel,
Diagramm,
exercise,
Kalziumkanal,
mibefradil,
mibefradil,
ST-segment depression,
ST-Segmentsenkung
|
| |
| |
|
|
Kalziumkanal - Mibefradil
Figure 13: Bar graph showing changes in the number and duration of silent ischaemia events with mibefradil treatment. A significant linear dose-response relation is shown across all treatment groups for ischaemic events and ischaemia duration, p < 0.001.
Keywords: calcium channel,
Diagramm,
ischaemia,
Ischämie,
Kalziumkanal,
mibefradil,
mibefradil
|
| |
| |
|
|