OBJECTIVETo demonstrate the inhibitory effect of kappa-opioid receptor activation by U50488H on hypertrophy induced by NE in cultured neonatal rat cardiac myocytes and compare its effect with that of prazosin and propranolol.

METHODSThe cellular proliferation was determined with crystal violet staining. The protein content was assayed with Lowry's method. The cardiomyocytes volumes were measured by computer photograph analysis system. The protein synthesis was assayed with [3H]-lencine incorporation method.

RESULTS(1) NE significantly induced the increase of protein content, [3H]-leucine incorporation and cell size without a concomitant increase in cell number in low serum medium. OThese responses were partially suppressed by prazosin or propranolol alone and completely abolished by both in combination. U50488H significantly inhibited the NE-induced increase of protein content, [3H]-leucine incorporation and cell size. The inhibitory effects of U50488H on NE-induced cardiac hypertrophy were greater than either prazosin or propranolol, but comparable to combination of both.

CONCLUSIONNE, acting via both alpha1- and beta-adrenergic pathway, stimulates myocyte hypertrophy. Stimulating kappa-opioid receptor significantly inhibits NE-induced cardiac hypertrophy, which may be related with alpha1- and beta1-adrenergic pathway.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer ; pharmacology ; Adrenergic alpha-1 Receptor Antagonists ; pharmacology ; Adrenergic beta-Antagonists ; pharmacology ; Animals ; Animals, Newborn ; Cardiomegaly ; chemically induced ; pathology ; prevention & control ; Cell Enlargement ; drug effects ; Cells, Cultured ; Female ; Male ; Myocytes, Cardiac ; cytology ; Norepinephrine ; Prazosin ; pharmacology ; Propranolol ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, Opioid, kappa ; agonists

OBJECTIVETo observe the effects of combined beta(1) adrenergic receptor (AR) antagonist with beta(2)AR agonist therapy on cardiac function and cardiomyocyte apoptosis in heart failure rats.

METHODSHeart failure was induced by isoproterenol and rats were randomly divided into metoprolol group (50 mg/kg twice daily/gavage, n = 11), combined treatment group (fenoterol 125 microg/kg and metoprolol 50 mg/kg twice daily/gavage, n = 11) and placebo group (saline, n = 10), another normal 9 male Wistar rats served as control group. After 8 weeks' treatment, cardiac function, apoptosis index (AI), Caspase-3 activity, expression levels of bcl-2 and bax protein, organ weight/body weight and collagen volume fraction (CVF) were evaluated.

RESULTS(1) Left ventricular end diastolic dimension, left ventricular end systolic dimension and E/A ratio were significantly increased and fractional shortening, ejection fraction significantly reduced post isoproterenol (all P < 0.05 vs. control) and these changes were significantly attenuated by metoprolol alone (all P < 0.05 vs. placebo) and further attenuated by the metoprolol and fenoterol combination therapy (all P < 0.05 vs. placebo and metoprolol). (2) Left ventricular weight to body weight ratio, lung weight to body weight ratio and CVF were also significantly reduced in metoprolol and combined treatment group than those in placebo group (all P < 0.01). (3) Compared with placebo group, AI and Caspase-3 activity were significantly lower in metoprolol group (all P < 0.01 vs. placebo) and further reduced in combined treatment group (all P < 0.01 vs. metoprolol). (4) The expression level of bax protein was significantly lower in metoprolol group while bcl-2/bax significantly higher than those in placebo group. These changes were more significant in combined treatment group (all P < 0.01 vs. metoprolol).

CONCLUSIONSbeta(1)AR antagonist in combination with beta(2)AR agonist further improved the cardiac function and prevented cardiac remodeling compared with using beta(1)AR antagonist alone in heart failure rats. Downregulated bax and upregulated bcl-2/bax expressions might contribute to the observed beneficial therapy effects by reducing cardiomyocyte apoptosis in these animals.

Adrenergic beta-1 Receptor Antagonists ; Adrenergic beta-2 Receptor Agonists ; Adrenergic beta-Agonists ; pharmacology ; therapeutic use ; Adrenergic beta-Antagonists ; pharmacology ; therapeutic use ; Animals ; Apoptosis ; drug effects ; Drug Therapy, Combination ; Heart Failure ; drug therapy ; Male ; Myocytes, Cardiac ; cytology ; Rats ; Rats, Wistar ; Ventricular Remodeling

Adrenal Cortex Hormones ; administration & dosage ; Adrenergic beta-2 Receptor Agonists ; Adrenergic beta-Agonists ; administration & dosage ; Asthma ; drug therapy ; Clinical Trials as Topic ; Drug Therapy, Combination ; Humans ; Patient Compliance ; Practice Guidelines as Topic ; Pulmonary Disease, Chronic Obstructive ; drug therapy

This study aims to elucidate the mechanisms by which dexmedetomidine alleviates pulmonary edema in rats with acute lung injury induced by lipopolysaccharide (LPS). Male Wistar rats were randomly divided into five groups: normal saline control (NS) group, receiving intravenous 0.9% normal saline (5 mL/kg); LPS group, receiving intravenous LPS (10 mg/kg); small-dose dexmedetomidine (S) group, treated with a small dose of dexmedetomidine (0.5 μg · kg(-1) · h(-1)); medium-dose dexmedetomidine (M) group, treated with a medium dose of dexmedetomidine (2.5 μg · kg(-1) · h(-1)); high-dose dexmedetomidine (H) group, treated with a high dose of dexmedetomidine (5 μg · kg(-1) · h(-1)). The rats were sacrificed 6 h after intravenous injection of LPS or NS, and the lungs were removed for evaluating histological characteristics and determining the lung wet/dry weight ratio (W/D). The levels of tumor necrosis factor-alpha (TNF-&alpha;) and interleukin-1&beta; (IL-1&beta;) in the lung tissues were assessed by enzyme- linked immunosorbent assay (ELISA). The mRNA and protein expression levels of aquaporin-1 (AQP1) and aquaporin-5 (AQP5) were detected by RT-PCR, immunohistochemistry, and Western blotting. The lung tissues from the LPS groups were significantly damaged, which were less pronounced in the H group but not in the small-dose dexmedetomidine group or medium-dose dexmedetomidine group. The W/D and the concentrations of TNF-&alpha; and IL-1&beta; in the pulmonary tissues were increased in the LPS group as compared with those in NS group, which were reduced in the H group but not in S group or M group (P<0.01). The expression of AQP1 and AQP5 was lower in the LPS group than in the NS group, and significantly increased in the H group but not in the S group or M group (P<0.01). Our findings suggest that dexmedetomidine may alleviate pulmonary edema by increasing the expression of AQP-1 and AQP-5.
Acute Lung Injury ; chemically induced ; drug therapy ; genetics ; pathology ; Adrenergic alpha-2 Receptor Agonists ; pharmacology ; Animals ; Aquaporin 1 ; agonists ; genetics ; immunology ; Aquaporin 5 ; agonists ; genetics ; immunology ; Dexmedetomidine ; pharmacology ; Dose-Response Relationship, Drug ; Drug Administration Schedule ; Gene Expression Regulation ; Injections, Intravenous ; Interleukin-1beta ; antagonists & inhibitors ; genetics ; immunology ; Lipopolysaccharides ; Lung ; drug effects ; immunology ; pathology ; Male ; Organ Size ; drug effects ; Pulmonary Edema ; chemically induced ; drug therapy ; genetics ; pathology ; Rats ; Rats, Wistar ; Signal Transduction ; Transcription, Genetic ; Tumor Necrosis Factor-alpha ; antagonists & inhibitors ; genetics ; immunology

The studies on gene polymorphisms in biological pathways of the drugs for the treatment of asthma refer to the studies in which pharmacogenetic methods, such as genome-wide association studies, candidate gene studies, genome sequencing, admixture mapping analysis, and linkage disequilibrium, are used to identify, determine, and repeatedly validate the effect of one or more single nucleotide polymorphisms on the efficacy of drugs. This can provide therapeutic strategies with optimal benefits, least side effects, and lowest costs to patients with asthma, and thus realize individualized medicine. The common drugs for asthma are &beta;2 receptor agonists, glucocorticoids, and leukotriene modifiers. This article reviews the research achievements in polymorphisms in biological pathways of the common drugs for asthma, hoping to provide guidance for pharmacogenetic studies on asthma in future and realize individualized medicine for patients with asthma soon.
Adrenergic beta-2 Receptor Agonists ; therapeutic use ; Asthma ; drug therapy ; genetics ; Glucocorticoids ; therapeutic use ; Leukotrienes ; genetics ; therapeutic use ; Metabolic Networks and Pathways ; Pharmacogenetics ; Polymorphism, Single Nucleotide ; Precision Medicine

A novel rapid method for detection of the illicit beta2-agonist additives in health foods and traditional Chinese patent medicines was developed with the desorption corona beam ionization mass spectrometry (DCBI-MS) technique. The DCBI conditions including temperature and sample volume were optimized according to the resulting mass spectra intensity. Matrix effect on 9 beta2-agonists additives was not significant in the proposed rapid determination procedure. All of the 9 target molecules were detected within 1 min. Quantification was achieved based on the typical fragment ion in MS2 spectra of each analyte. The method showed good linear coefficients in the range of 1-100 mg x L(-1) for all analytes. The relative deviation values were between 14.29% and 25.13%. Ten claimed antitussive and antiasthmatic health foods and traditional Chinese patent medicines from local pharmacies were analyzed. All of them were negative with the proposed DCBI-MS method. Without tedious sample pretreatments, the developed DCBI-MS is simple, rapid and sensitive for rapid qualification and semi-quantification of the illicit beta2-agonist additives in health foods and traditional Chinese patent medicines.
Adrenergic beta-2 Receptor Agonists ; analysis ; Drugs, Chinese Herbal ; chemistry ; Food, Organic ; analysis ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Substance Abuse Detection ; methods ; Tandem Mass Spectrometry

AIMTo study the effects of beta 2-adrenergic receptor-selective agonist clenbuterol on nitrogen metabolism and glucose-6-phosphate dehydrogenase activity of rat hepatocyte and its pharmacological mechanism.

METHODSBiochemical methods were used to study the influence of clenbuterol on urea-nitrogen concentration of hepatocyte culture medium, 3H-leucine incorporation into hepatocyte, insulin-like growth factor I (IGF-I) production and glucose-6-phosphate dehydrogenase (G6PDH) activity of rat hepatocyte.

RESULTSThe results showed that urea-nitrogen production by cultured rat hepatocytes was markedly affected with clenbuterol treatment (1 x 10(-6) mol.L-1), urea-nitrogen concentration of culture medium was decreased by 25.51% (P < 0.05) compared with control. The inhibitory effect of hepatocyte urea-nitrogen production of clenbuterol was blocked by propranolol, a beta-adrenoreceptor antagonist (1 x 10(-6) mol.L-1), but hepatocyte urea-nitrogen level was not affected with propranolol treatment only (P > 0.05). The content of 3H-leucine incorporation in rat hepatocyte was significantly increased by 23.35% (P < 0.05) with clenbuterol-treatment (1 x 10(-6) mol.L-1), and the enhanced effect of 3H-leucine incorporation into hepatocyte was antagonized by propranolol (1 x 10(-6) mol.L-1. The level of 3H-leucine incorporation of rat hepatocyte was not influenced by propranolol alone. IGF-I production of rat hepatocyte might be affected by clenbuterol. IGF-I concentration of culture medium was increased by 39.46% with clenbuterol (1 x 10(-6) mol.L-1), but no significant difference was found compared with the control (P > 0.05). Moreover, G6PDH activity of rat hepatocyte was significantly decreased by 43.36% (P < 0.05) with clenbuterol treatment (1 x 10(-6) mol.L-1), and the declined effect of clenbuterol was antagonized by propranolol. G6PDH activity of rat hepatocyte was not affected on condition that propranolol was administered alone (P > 0.05).

CONCLUSIONIt is suggested that clenbuterol may regulate nitrogen and fat metabolism by means of increasing nitrogen retention and protein synthesis, and decreasing G6PDH activity of rat hepatocyte for pharmacological effects.

Adrenergic beta-2 Receptor Agonists ; Animals ; Cells, Cultured ; Clenbuterol ; pharmacology ; Glucosephosphate Dehydrogenase ; metabolism ; Hepatocytes ; drug effects ; enzymology ; metabolism ; Nitrogen ; metabolism ; Rats ; Rats, Sprague-Dawley

Adrenal Cortex Hormones ; metabolism ; Adrenergic beta-2 Receptor Agonists ; metabolism ; Humans ; Multiple Pulmonary Nodules ; diagnosis ; metabolism ; pathology ; Pulmonary Disease, Chronic Obstructive ; diagnosis ; metabolism ; pathology ; World Health Organization

BACKGROUND AND OBJECTIVES: Knowing the ototoxic potential of the agents used in medical treatments is important for the protection of hearing. Although we have knowledge regarding some effects of dexmedetomidine, which is an anesthetic-sparing drug, its influence over the hearing system has never been studied and is obscure yet. The aim of this study is to determine the effects of intravenous dexmedetomidine application during sevoflurane anesthesia on otoacoustic emissions (OAEs). SUBJECTS AND METHODS: This prospective randomized study was performed on 60 patients (34 male, 26 female, mean age: 30.6±9.2 years) who were scheduled for an elective surgery under general anesthesia and the patients were enrolled and randomly divided into 2 groups. They received dexmedetomidine (Group D) or Saline (Group S) infusion during a standardized Sevoflurane anesthesia. Transient and distortion product OAEs were measured preoperatively and postoperatively (24th hour). OAE results were compared within and between groups. RESULTS: In group D postoperative OAEs were lower than preoperative OAEs and postoperative levels of group S, especially at low frequencies (p<0.05). CONCLUSIONS: Dexmedetomidine infusion affects the micromechanical function of cochlea especially in the low-frequency region. Dexmedetomidine should be carefully used during general anesthesia to avoid its probable harmful effects on cochlear micromechanics.
Adrenergic alpha-2 Receptor Agonists ; Anesthesia ; Anesthesia, General ; Cochlea ; Dexmedetomidine ; Female ; Hearing ; Humans ; Male ; Prospective Studies

BACKGROUND: This study evaluated the effect of decrease in loading dose administration rate of dexmedetomidine (DMT) on sedation and DMT requirement in elderly patients. METHODS: Fifty-eight patients over 65 years old with ASA I–II who were planned to receive DMT sedation during spinal anesthesia were randomly assigned to two groups. Group S (n = 29) received a 0.5 µg/kg DMT loading dose over 20 minutes, while group C (n = 29) received the DMT loading dose over 10 minutes. Then, both groups received a continuous infusion of 0.4 µg/kg/h. The sedative status was recorded before and at 5, 10, 15, 20, 25, and 30 minutes after administration of DMT and at the end of the anesthesia according to the Ramsay sedation scale (RSS). Also, the time to reach RSS-3 (patients asleep, responsive to commands) and the dose of DMT until reaching RSS-3 were recorded. RESULTS: The time to reach RSS-3 was similar between the two groups (group S = 16.0 ± 4.3 minutes vs. group C = 15.5 ± 4.2 minutes, P = 0.673). However, the DMT required to reach RSS-3 in group S was significantly lower than that in group C (23.3 ± 7.1 vs. 32.5 ± 6.0 µg, P < 0.001). There was no difference in RSS between the two groups from the administration of DMT to the end of the anesthesia (P = 0.927). CONCLUSIONS: Decreasing the administration rate of the DMT loading dose did not delay the onset of RSS-3 sedation and reduced the DMT requirement in elderly patients.
Adrenergic alpha-2 Receptor Agonists ; Aged* ; Anesthesia ; Anesthesia, Spinal* ; Dexmedetomidine* ; Humans ; Hypnotics and Sedatives