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

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

Angiotensin II ; metabolism ; Cells, Cultured ; Endothelial Cells ; drug effects ; secretion ; Endothelins ; secretion ; Humans ; Polyphenols ; pharmacology ; Propanolamines ; pharmacology ; Tea ; chemistry ; Weightlessness Simulation

Adrenergic beta-Antagonists ; pharmacology ; Animals ; Cardiopulmonary Resuscitation ; Diastole ; drug effects ; Female ; Male ; Natriuretic Peptide, Brain ; blood ; Propanolamines ; pharmacology ; Rabbits ; Ventricular Function, Left ; drug effects

BACKGROUND: Sevoflurane is widely used to anesthetize children because of its rapid action with minimal irritation of the airways. However, there is a high risk of agitation after emergence from anesthesia. Strabismus surgery, in particular, can trigger agitation because patients have their eyes covered in the postoperative period. The aim of this study was to determine whether or not esmolol and lidocaine could decrease emergence agitation in children. METHODS: Eighty-four patients aged 3 to 9 years undergoing strabismus surgery were randomly assigned to a control group (saline only), a group that received intravenous lidocaine 1.5 mg/kg, and a group that received intravenous esmolol 0.5 mg/kg and lidocaine 1.5 mg/kg. Agitation was measured using the objective pain score, Cole 5-point score, and Richmond Agitation Sedation Scale score at the end of surgery, on arrival in the recovery room, and 10 and 30 min after arrival. RESULTS: The group that received the combination of esmolol and lidocaine showed lower OPS and RASS scores than the other two groups when patients awoke from anesthesia (OPS = 0 (0-4), RASS = -4 [(-5)-1]) and were transferred to the recovery room (OPS = 0 (0-8), RASS = -1 [(-5)-3]) (P < 0.05). There was no significant difference in the severity of agitation among the three groups at other time points (P > 0.05). CONCLUSIONS: When pediatric strabismus surgery is accompanied by sevoflurane anesthesia, an intravenous injection of esmolol and lidocaine could alleviate agitation until arrival in the recovery room. TRIAL REGISTRATION Clinical Research Information Service, No. KCT0002925; https://cris.nih.go.kr/cris/en/search/search_result_st01.jsp?seq=11532.
Anesthesia ; methods ; Child ; Child, Preschool ; Double-Blind Method ; Humans ; Injections, Intravenous ; Lidocaine ; administration & dosage ; pharmacology ; Propanolamines ; administration & dosage ; pharmacology ; Sevoflurane ; therapeutic use ; Strabismus ; surgery ; Wakefulness ; drug effects

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

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

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 examine serum B-type natriuretic peptide (BNP) levels and BNP expression of protein and mRNA in the right ventricular myocardium in juvenile rats with right heart failure (RHF) and the effects of beta-adrenergic receptor blocker carvedilol on serum and myocardial BNP levels in order to investigate the role of BNP in the diagnosis and treatment of RHF.

METHODSFifty-one four-week-old Sprague-Dawley rats were randomly assigned to 5 groups: RHF 1, RHF 2, carvedilol-treated RHF, control 1 and control 2. RHF was developed 4 weeks after an intraperitoneal injection of monocrotaline in the RHF 1, RHF 2 and carvedilol-treated RHF groups. The rats in the RHF 1 and the control 1 groups were sacrificed after the RHF event for observing pathological changes in the myocardium. After the RHF event, the carvedilol-treated group was given intragastric administration of carvedilol (3.5 mg/kg/d) for 2 weeks. The RHF 2 and the control 2 groups were given distilled water of equal dose instead. The rats were sacrificed 2 weeks after carvedilol or distilled water administration. Serum BNP levels were measured using ELISA. BNP protein and mRNA expression in the right ventricular myocardium were measured by immunohistochemistry and RT-PCR, respectively. Haemodynamics and some physiological indexes were measured.

RESULTSSerum BNP levels and BNP protein and mRNA expression in the right ventricular myocardium were significantly higher in the RHF 1 group than those in the control 1 group (p<0.01). Serum BNP levels and BNP protein and mRNA expression in the right ventricular myocardium increased more significantly in the RHF 2 group. There was a positive correlation between serum BNP levels and myocardial BNP protein expression in the RHF group (r=0.698, p<0.01). Serum BNP levels and BNP protein and mRNA expression in the carvedilol-treated RHF group were significantly reduced when compared with the RHF 2 group (p<0.05). Carvedilol treatment also resulted in improved hemodynamics and relieved right ventricular hypertrophy.

CONCLUSIONSBNP may serve an index for the diagnosis of RHF and the evaluation of severity in children with RHF. Carvedilol shows protections against RHF caused by pressure load.

Adrenergic beta-Antagonists ; pharmacology ; Animals ; Carbazoles ; pharmacology ; therapeutic use ; Heart Failure ; blood ; drug therapy ; pathology ; physiopathology ; Natriuretic Peptide, Brain ; blood ; genetics ; Propanolamines ; pharmacology ; therapeutic use ; RNA, Messenger ; analysis ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the effects of carvedilol on stabilizing atherosclerosis plaque.

METHODSForty five male Japanese white rabbits were divided randomly into 5 groups with 9 for each. One group was fed up with normal diet as blank control. In other four groups, the common carotid artery of rabbits fed up with high cholesterol diet were injured by balloon. Three groups of them were transfected by wild-type p53 gene 8 weeks later, and then two groups of them were treated with carvedilol (3 mgxkg(-1)xd(-1)) and metoprolol (6 mgxkg(-1)xd(-1)) respectively, high cholesterol diet should be continued for other 4 weeks. Serum lipid, hypersensitive C-reaction protein (hsCRP), oxidized low density lipoprotein (oxLDL), superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-PX) were measured in 0, 8, 12 weeks after experiment. The apoptosis rate of smooth muscle cell (SMC) in endomembrane and the local expression of p53, bcl-2, bax, alpha-actin were examined after experiment, and the carotid arteries were examined by light microscopy and transmission electron microscopy.

RESULTSThe typical carotid atherosclerotic plaques were observed in balloon-injured groups. The local expression rates of p53 in groups transfected by wild type p53 gene were higher obviously than them in other two groups (P < 0.01). Compared with the rabbits received simple transfection, the thickness of the fibrous cap in rabbits received carvedilol and metoprolol were all increased, but the change could be observed significantly in carvedilol group (P < 0.05). Compared with metoprolol, carvedilol could reduce the level of serum hsCRP, oxLDL, MDA, and increase the concentration of SOD and GSH-PX significantly (P < 0.05 or 0.01), but two medicines had no obvious influence to serum lipid. The apoptosis rate of SMC in endomembrane, the local expression of bax gene and bax/bcl-2 ratio were decreased, the positive expression rates of alpha-actin and bcl-2 were enhanced in carvedilol group (P < 0.01).

CONCLUSIONSBoth carvedilol and metoprolol can improve the stability of the plaque, but carvedilol is superior. Its mechanisms may lie in that carvedilol still has function of anti-inflammation, anti-oxidation, decreasing the apoptosis rate of SMC in addition to its function of blocking beta-receptor.

Animal Feed ; Animals ; Apoptosis ; drug effects ; Carbazoles ; pharmacology ; Carotid Artery Diseases ; genetics ; pathology ; Genes, p53 ; Humans ; Male ; Metoprolol ; pharmacology ; Oxidative Stress ; drug effects ; Propanolamines ; pharmacology ; Rabbits ; Transfection ; Tumor Suppressor Protein p53 ; genetics ; metabolism