The paper is aimed to investigate the pharmacokinetic (PK) and the pharmacodynamic (PD) properties of carvedilol using indirect response and effect-compartment link models, and compare the fitness of PK-PD models. Twenty male healthy Chinese volunteers received a single oral dose of 20 mg of carvedilol. The plasma concentrations of carvedilol were determined by reversed-phase HPLC method with fluorescence detection, and the pharmacokinetic parameters were calculated by DAS2.0. The mean arterial blood pressure was measured and the pharmacodynamics of carvedilol was characterized by tail-cuff manometry. The main pharmacokinetic parameters of carvedilol were as follows, t1/2 (4.56 +/- 2.56) h, Cmax (46.29 +/- 21.07) ng x mL(-1), AUC(0-infinity) (173.76 +/- 87.36) ng x mL(-1) x h. The estimated Kin was (0.41 +/- 0.31)% h(-1), Kout was (0.40 +/- 0.26) h(-1), the IC50 value was (24.40 +/- 21.10) ng x mL(-1) and the area under the effect curve (AUE) was (3.82 +/- 1.46)% h for the indirect response PD model. The Ke0 was (0.35 +/- 0.27) h(-1), the EC50 was (24.30 +/- 24.30) ng x mL(-1), and the AUE was (5.65 +/- 2.54)% h for the effect-compartment model. The HPLC method can be used for the pharmacokinetic study of carvedilol. The proposed effect-compartment link model provided more appropriate and better-fitting PK/PD characteristics than the indirect response model in Chinese healthy volunteers according to Akaike's information criterion values.
Antihypertensive Agents ; pharmacokinetics ; pharmacology ; Area Under Curve ; Blood Pressure ; drug effects ; Carbazoles ; blood ; pharmacokinetics ; pharmacology ; Humans ; Male ; Models, Cardiovascular ; Propanolamines ; blood ; pharmacokinetics ; pharmacology

Experiments were performed to investigate the effects of long-term treatment with adrenergic receptor antagonist on electrical remodeling of the left ventricle with chronic pressure-overload. New Zealand rabbits underwent subtotal banding of superrenal abdominal aorta. At 10 weeks after surgery, echocardiography examination was performed, then action potential (AP), inward rectifier potassium current (I(Ki)), delayed rectifier potassium current (I(K)) and Na(+)/Ca(2+) exchanger current (I(Na(+)/Ca(2+))) were recorded in midmyocardial cells isolated from left ventricle of abdominal aorta banded group (banded group), abdominal aorta banding plus Carvedilol intervention group (Carvedilol group), and normal control group rabbits by using the whole-cell patch-clamp techniques. The results showed that left ventricular mass index in control, banded, and Carvedilol groups were 1.78+/-0.06 (n=7), 2.33+/-0.11 (n=7), and 1.87+/-0.08 (n=7), respectively (banded vs control and Carvedilol, P<0.01). At basic cycle length of 2 s, AP duration (measured at 90% repolarization, APD(90), ms) in control, banded, and Carvedilol groups were 522.0+/-19.5 (n=6), 664.7+/-46.2 (n=7), 567.8+/-14.3 (n=8) respectively (banded vs control, P<0.01; Carvedilol vs banded, P<0.05). At test potential of -100 mV, inward I(Ki) density (pA/pF) in control, banded, and Carvedilol groups were -11.8+/-0.50 (n=8), -8.07+/-0.28 (n=8), -10.69+/-0.35 (n=8) respectively (banded vs control and Carvedilol, P<0.01). At test potential of +50 mV, I(K) tail current density (pA/pF) in control, banded, and Carvedilol groups were 0.59+/-0.04 (n=8), 0.40+/-0.02 (n=9), 0.51+/-0.02 (n=8) respectively (banded vs control, P<0.01; Carvedilol vs banded, P<0.05). At test potential of +60 mV, outward I(Na(+)/Ca(2+)) density (pA/pF) in control, banded, and Carvedilol groups were 1.06+/-0.11 (n=8), 1.54+/-0.10 (n=9), 1.24+/-0.07 (n=8), respectively (banded vs control and Carvedilol, P<0.01). At test potential of -120 mV, inward I(Na(+)/Ca(2+)) density (pA/pF) in control, banded, and Carvedilol groups were -0.54+/-0.06 (n =8), -0.75+/-0.04 (n=9), -0.60+/-0.03 (n=8), respectively (banded vs control, P<0.01; Carvedilol vs banded, P<0.05). It is shown that long-term treatment with Carvedilol not only prevents development of cardiac hypertrophy, but also improves the electrophysiological alterations in rabbit hearts with chronic pressure-overload. This finding may add new electrophysiological evidence for the treatment of heart failure and hypertension with adrenergic receptor antagonist.
Action Potentials ; Adrenergic Antagonists ; pharmacology ; Animals ; Carbazoles ; pharmacology ; Cardiac Output, Low ; physiopathology ; Electrophysiology ; Female ; Male ; Patch-Clamp Techniques ; Propanolamines ; pharmacology ; Rabbits ; Ventricular Remodeling ; drug effects

OBJECTIVETo investigate apoptosis-inducing effect and its mechanisms of HY-1, a carbazole alkaloid, on human erythroleukemia K562 cells.

METHODSCell proliferation was detected by sulforhodamine B (SRB) assay after treated with HY-1 at indicated doses. Cell cycle analysis was performed by flow cytometry, mitochondria membrane voltage change was assessed by rhodamine 123 staining, annexin V-PI apoptosis detecting kit and DNA agarose gel electrophoresis were used to identify apoptosis-inducing effect of HY-1. The alterations of apoptosis-relating proteins were detected by Western blot.

RESULTSThe IC(50) of HY-1 in K562 cells was (29.05 +/- 0.90) micromol/L by SRB assay. HY-1 had significant apoptotic inducing effect on K562 cells in a dose- and time-dependent manner as verified by appearance of Sub-G(1) peak on histogram of flow cytometry analysis, reduction of mitochondria membrane voltage, appearance of double positive cell group in Annexin V-PI apoptosis detecting test, and remarkable DNA ladder. The expression of cytosolic cytochrome c was apparently increased. Pro-caspase-9, pro-caspase-3 and PARP were all cleaved to active segments. There was no change in the expression of caspase-8.

CONCLUSIONHY-1 exerts its anticancer activity through triggering apoptosis of K562 cells by mitochondria-activating pathways.

Alkaloids ; isolation & purification ; pharmacology ; Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Carbazoles ; isolation & purification ; pharmacology ; Humans ; K562 Cells ; Mitochondria ; metabolism ; Rutaceae ; chemistry

AIMTo design and synthesize new methoxyl carbazole analogues as antitumor compounds.

METHODSMethoxyl-nitrobiphenyls (3a-3c) were prepared through the Ullmann reaction of 4,5-dimethoxyl-2-bromonitrobenzene and methoxyl-iodobenzene compounds with the catalysis of copper powder, and then reduced by P(EtO)3 to obtain methoxyl carbazoles 4a-4c. The modification at 9-position of the methoxyl carbazoles (4a-4c) gives 16 carbazole derivatives (5a-5p). These compounds were confirmed by 1HNMR, MS, IR and elemental analysis.

RESULTIn vitro antitumor activities evaluation in vitro demonstrated that IC50 value of the target compounds 4c, 5a, 5b, 5g, 5h, 5i, 5l, 5n and 5p against HT-29 cells were 12.1, 10.6, 8.1, 3.1, 4.4, 10.1 and 9.2 micromol x L(-1) respectively, and IC50 value of the target compound 4a against KB was 17.7 micromol x L(-1).

CONCLUSIONSome of the target compounds have better inhibitory effects against H-29 and KB cells.

Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Carbazoles ; chemical synthesis ; chemistry ; pharmacology ; HT29 Cells ; drug effects ; Humans ; KB Cells ; drug effects ; Molecular Structure

OBJECTIVETo explore change of ryanodine receptor (RyR) in junior mouse with heart failure (HF) and the effect of β-adrenoreceptor blocker and Radix astragali on RyR in HF in this experiment.

METHODThe animal model of congestive heart failure was established by coarctation of abdominal aorta. Five weeks old mice were randomly divided into 4 groups: (1) HF group without treatment (n = 30); (2) HF group treated with carvedilol (n = 30); (3) HF group treated with carvedilol and Radix astragali(n = 30); (4) Sham-operated group (n = 30). Carvedilol and Radix astragali were administered through direct gastric gavage. After 4 weeks of treatment the high frequency ultrasound was performed. Myocardial sarcoplasmic reticulum (SR) was fractionated with ultra centrifugation. The time courses of Ca(2+) uptake and leak were determined by fluorescent spectrophotometry. The levels of expression of RyR2 in the 4 groups were detected by semi-quantitative reverse transcription-polymerase chain reaction.

RESULTCompared with the sham-operated group, left ventricular diastolic dimension (LVEDD) (P < 0.05), left ventricular systolic dimension (LVESD), interventricular septal thickness at end-diastole (IVSTd), interventricular septal thickness at end-systole (IVSTs), left ventricular posterior wall thickness at end-diastole (LVPWTd), and left ventricular posterior wall thickness at endsystole (LVPWTs) were all significantly increased (P < 0.01), ejection fraction (EF)(%) (HF group without treatment 51.60 ± 1.15, HF treated with carvedilol 72.06 ± 1.39, HF treated with carvedilol and Radix astragali 79.06 ± 1.09, sham-operated group 85.86 ± 1.45) and fractional shortening (FS) (HF group without treatment 44.55 ± 1.20, HF treated with carvedilol 44.55 ± 1.20, HF treated with carvedilol and Radix astragali 53.58 ± 1.30, sham-operated group 59.03 ± 1.67) were decreased (P < 0.01) in HF group without treatment. LVEDD (P < 0.05), LVESD, IVSTd, IVSTs, LVPWTd and LVPWTs were all significantly decreased (P < 0.01), EF and FS were increased (P < 0.01) in the cases with HF treated with carvedilol and carvedilol and Radix astragali when compared with HF group without treatment. EF and FS were much more increased in the group treated with carvedilol and Radix astragali than in those treated with carvedilol (P < 0.05). After adding thapsigargin to the buffer including SR of the four groups, there were fewer Ca(2+) leak (%) in sham-operated group (11.5 ± 4.3), HF group treated with carvedilol (15.6 ± 5.8) and treated with carvedilol and Radix astragali (13.6 ± 4.8) than that of HF group without treatment (65.6 ± 6.2) (P < 0.01), while after adding FK506 and thapsigargin together to the buffer including SR of four groups, there were marked Ca(2+) leak in sham-operated group (60.6 ± 7.8), HF group treated with carvedilol (66.2 ± 4.5)and those treated with carvedilol and Radix astragali (70.2 ± 5.5, P < 0.01). However, there was no additional increase in Ca(2+) leak in HF group (67.3 ± 7.5) compared with that of the group where only thapsigargin was added (P > 0.05). The levels of expression of RyR2 were significantly decreased in HF group and increased in the group treated with carvedilol and the group treated with carvedilol and Radix astragali.

CONCLUSIONThere was more cardiac Ca(2+) leak and the expression of RyR2 mRNA decreased in HF. Carvedilol and Radix astragali can increase expression of RyR2 mRNA and inhibit Ca(2+) leak by restoring the binding of FKBP12.6 back to RyR in HF to improve cardiac function and prevent left ventricle from remodeling.

Adrenergic beta-Antagonists ; pharmacology ; Animals ; Astragalus Plant ; Carbazoles ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Heart Failure ; metabolism ; Male ; Propanolamines ; pharmacology ; Rats ; Rats, Wistar ; Ryanodine Receptor Calcium Release Channel ; drug effects ; metabolism

OBJECTIVEBrain-derived neurotrophic factor (BDNF) and its specific tryrosin kinase receptor-B (TrkB) are highly correlated to the chemoresistance of neuroblastoma (NB) cells and poor prognosis. This study observed the changes of the sensibility of NB cells to chemotherapy drug cisplatin (CDDP) before and after blockage of TrkB-BDNF signal pathway by specific tyrosin kinase inhibitor K252a.

METHODSHuman NB cell line SH-SY5Y (SY5Y) was routinely cultured. Expression of TrkB was induced with nM all trans-retinoid acid (ATRA). Then BDNF, CDDP or K252a were added to the cultured SY5Y cells. Cell livability was assessed by methyl thiazolyl tetrazolium (MTT) assay. TrkB autophosphorylation was determined by Western blot analysis. Cell apoptosis rate was detected by flow cytometry (FCM). The conformation of apoptosis cells was observed by transmission electron microscopy (TEM).

RESULTSThe livability and apoptosis rate in SY5Y cells treated with ATRA, BDNF and CDDP were not different from the blank control group. However, after K252a together with ATRA, BDNF and CDDP treatment, the sensibility of SY5Y cells to chemotherapy drug CDDP increased, the livability decreased and the apoptosis rate increased in SY5Y cells when compared with the blank control group (P <0.01). K252a treatment resulted in blockage of TrkB autophosphorylation.

CONCLUSIONSThe blockage of TrkB-BDNF signal pathway by K252a use can increase sensibility of NB cells to chemotherapy and thus decrease the livability of NB cells.

Apoptosis ; drug effects ; Brain-Derived Neurotrophic Factor ; antagonists & inhibitors ; Carbazoles ; pharmacology ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Humans ; Indole Alkaloids ; pharmacology ; Microscopy, Electron, Scanning ; Neuroblastoma ; drug therapy ; pathology ; Receptor, trkB ; antagonists & inhibitors ; Signal Transduction ; drug effects ; Tretinoin ; pharmacology

BACKGROUNDCarvedilol, an antagonist of alpha1- and beta-adrenergic receptors, has shown efficacy in reducing all-cause death and arrhythmia death for ischemic heart disease and congestive heart failure in several large-scale trials. It has been found to prevent ventricular remodeling, and recently was reported to reverse down-regulation of Na+ channel in a chronic heart failure model. This study was conducted to investigate whether carvedilol could reverse the ion remodeling in a myocardial infarction model of rabbit.

METHODSAfter the procedure of coronary ligation, animals were randomized to placebo or carvedilol treatment (5 mg/kg). Action potentials, L-type calcium current (Ica L) and the effect of isoproterenol stimulation on Ica L were measured using whole-cell patch method. Evaluation of the expression of calcium channel subunits was carried out by RT-PCR and Western blot.

RESULTSThe results indicate that mean peak Ica L densities (pA/pF) at +10 mV was reduced in postinfarction myocytes (5.33 +/- 0.45, n = 25) compared to sham myocytes (6.52 +/- 0.21, n = 20). Treatment of myocardial infarction rabbits with carvedilol could restore it partially (5.91 +/- 0.39, n = 20, P < 0.05). However, steady-state activation parameters were similar in three groups. With stimulation by isoproterenol (1 micromol/L) Ica L increased in all three groups, but the increase was smaller in postinfarction myocytes. mRNA levels of calcium channel subunit CaA1 gene was decreased but CaB2a, CaB2b and CaB3 mRNA levels did not change after MI. Corresponding change in CaA1 protein was also observed.

CONCLUSIONSThe results demonstrate that carvedilol restores Ica L density and reverse the downregulation of CaA1 postinfarction.

Action Potentials ; drug effects ; Adrenergic beta-Antagonists ; pharmacology ; Animals ; Calcium Channels, L-Type ; biosynthesis ; genetics ; metabolism ; Carbazoles ; pharmacology ; Male ; Myocardial Infarction ; metabolism ; physiopathology ; Propanolamines ; pharmacology ; Rabbits ; Random Allocation ; Ventricular Remodeling ; drug effects

The protective effect of carvedilol on abnormality of L-type calcium current induced by oxygen free radical in single guinea pig ventricular myocytes was studied. Whole-cell patch clamp technique was used to study the effect of H2O2 (0.5 mmol/L) on L-type calcium current in single guinea pig ventricular myocytes and the action of pretreatment with carvedilol (0.5 micromol/L). 0.5 micromol/L carvedilol had no significant effect on ICa,L and its channel dynamics. In the presence of 0.5 mmol/L H2O2, peak current of ICa,L was reduced significantly (P<0.001), the I-V curve of ICa,L was shifted upward, steady-state activation curve and steady-state deactivation curve of ICa,L were shifted left and recovery time of ICa,L was delayed significantly (P<0.001). 0.5 micromol/L carvedilol significantly alleviated the inhibitory effect of H2O2 on ICa,L as compared with that in H2O2 group (P<0.01). In addition, carvedilol reversed the changes of dynamics of ICa,L induced by H2O2. It was concluded that carvedilol could alleviate the abnormality of L-type calcium current induced by oxygen free radical in cardiomyocytes. It shows partly the possible mechanism of the special availability of carvedilol in chronic heart failure.
Adrenergic beta-Antagonists ; pharmacology ; Animals ; Calcium Channels, L-Type ; metabolism ; Carbazoles ; pharmacology ; Female ; Free Radicals ; adverse effects ; Guinea Pigs ; Heart Ventricles ; cytology ; Male ; Myocytes, Cardiac ; metabolism ; pathology ; Oxidative Stress ; Patch-Clamp Techniques ; Propanolamines ; pharmacology

This article reports the investigation of the effect of carvedilol (Car) on T-type calcium current (I(Ca,T)) of noninfarcted ventricular myocytes in rabbit models of healed myocardial infarction (HMI). Rabbits with left anterior descending artery ligation were prepared and allowed to recover for 8 weeks, as HMI group. Animals undergoing an identical surgical procedure without coronary ligation were served as the sham-operated group (sham group). Whole cell voltage-clamp techniques were used to measure and compare currents in cells from the different groups. Noting that I(Ca,T) density in HMI cells increased markedly to -2.36 +/- 0.12 pA/pF (at -30 mV) compared with cells of sham, where little I(Ca,T) (-0.35 +/- 0.02 pA/pF) was observed. Meanwhile, further analysis revealed a significant hyperpolarizing shift of steady-state activation curve of I(Ca,T) in HMI cells, where the time constants of deactivation were prolonged and the time of recovery from inactivation was shortened. Finally, the amplitude of I(Ca,T) was increased. Carvedilol (1 micromol x L(-1)) was found to decrease the amplitude of I(Ca,T) to -1.38 +/- 0.07 pA/pF through inhibiting process of I(Ca,T) activation. Furthermore, carvedilol delayed recovery from inactivation of I(Ca,T) and shortened the time constants of deactivation in HMI cells. This study suggested that the application of carvedilol in HMI cells contributes to the dynamic changes in I(Ca,T) and may account for reduction of incidence of arrhythmia after myocardial infarction.
Adrenergic beta-Antagonists ; pharmacology ; Animals ; Calcium Channels, T-Type ; drug effects ; Carbazoles ; pharmacology ; Female ; Male ; Myocardial Infarction ; pathology ; physiopathology ; Myocytes, Cardiac ; drug effects ; physiology ; Patch-Clamp Techniques ; Propanolamines ; pharmacology ; Rabbits

OBJECTIVETo evaluate the effects of Carvedilol on cardiopulmonary bypass (CPB)-induced myocardiocyte apoptosis and its effects on regulation of Fas, FasL expression, caspase-3 activity and oxidative stress in the left ventricle (LV) in this setting.

METHODSTen adult dogs undergoing conventional hypothermic CPB were randomly divided into control and Carvedilol treated groups (n = 5, respectively). Dogs in Carvedilol treated group received a bolus of Carvedilol (1 mg/kg) intravenously and a maintenance dosage of Carvedilol (3 micro g.min(-1).kg(-1)) for 3 hours after the reperfusion of the heart. Dogs in control group received no Carvediolol. LV samples were obtained before, during and 3 hours after CPB. In situ nick end-labeling (TUNEL) technique was used to detect the apoptotic cells. The expressions of Fas and FasL were detected immunohistochemically and quantified by fluorescence activated cell sorting (FACS). The activity of caspase-3 enzyme and malondialdehyde (MDA) level were measured by cleavage of Z-DEVD-AMC substrate and thiobarbituric acid reactive substance (TBARS) method, respectively.

RESULTSBefore and during CPB, all the parameters were not significantly different intra- or between groups (P > 0.05). After CPB, these parameters in both groups were significantly elevated compared with those of before and during CPB (P < 0.028, respectively). However, the number of apoptotic cells in Carvedilol treated group was significantly decreased compared with that of the control group (P < 0.021). The expressions of Fas and FasL were significantly downregulated by Carvedilol (P < 0.001 and 0.003, respectively). The caspase-3 activity and the content of MDA in the Carvedilol treated group was also significantly reduced (P < 0.026 and 0.005, respectively).

CONCLUSIONSCarvedilol significantly reduces CPB-induced cardiomyocyte apoptosis in dog hearts and the reduction of cardiomyocyte apoptosis is associated with downregulation of Fas and FasL expression, inhibition of caspase-3 activity and oxidative stress in LV.

Adrenergic beta-Antagonists ; pharmacology ; Animals ; Apoptosis ; Carbazoles ; pharmacology ; Cardiopulmonary Bypass ; Caspase 3 ; Caspases ; metabolism ; Dogs ; Down-Regulation ; Fas Ligand Protein ; Female ; In Situ Nick-End Labeling ; Male ; Membrane Glycoproteins ; metabolism ; Myocytes, Cardiac ; cytology ; metabolism ; Propanolamines ; pharmacology ; Signal Transduction ; fas Receptor ; metabolism