brl-37344 and Disease-Models--Animal

brl-37344 has been researched along with Disease-Models--Animal* in 13 studies

Other Studies

13 other study(ies) available for brl-37344 and Disease-Models--Animal

ArticleYear
Effect of Beta 3 Adrenoreceptor Modulation on Patency of the Ductus Arteriosus.
    Cells, 2020, 12-07, Volume: 9, Issue:12

    β3-adrenoreceptor (β3-AR), a G-protein coupled receptor, has peculiar regulatory properties in response to oxygen and widespread localization. β3-AR is expressed in the most frequent neoplasms, also occurring in pregnant women, and its blockade reduces tumor growth, indicating β3-AR-blockers as a promising alternative to antineoplastic drugs during pregnancy. However, β3-AR involvement in prenatal morphogenesis and the consequences of its blockade for the fetus remain unknown. In this study, after the demonstrated expression of β3-AR in endothelial and smooth muscle cells of ductus arteriosus (DA), C57BL/6 pregnant mice were acutely treated at 18.5 of gestational day (GD) with indomethacin or with the selective β3-AR antagonist SR59230A, or chronically exposed to SR59230A from 15.5 to 18.5 GD. Six hours after the last treatment, fetuses were collected. Furthermore, newborn mice were treated straight after birth with BRL37344, a β3-AR agonist, and sacrificed after 7 h. SR59230A, at the doses demonstrated effective in reducing cancer progression (10 and 20 mg/kg) in acute and chronic mode, did not induce fetal DA constriction and did not impair the DA ability to close after birth, whereas at the highest dose (40 mg/kg), it was shown to cause DA constriction and preterm-delivery. BRL37344 administered immediately after birth did not alter the physiological DA closure.

    Topics: Adrenergic beta-3 Receptor Antagonists; Animals; Animals, Newborn; Disease Models, Animal; Disease Progression; Ductus Arteriosus; Ductus Arteriosus, Patent; Ethanolamines; Female; Indomethacin; Male; Maternal Exposure; Mice; Mice, Inbred C57BL; Pregnancy; Pregnancy, Animal; Propanolamines; Receptors, Adrenergic, beta-3; Receptors, G-Protein-Coupled; Time Factors

2020
Effect of co-administration of BRL-37344 and tadalafil on reduction of overactive bladder symptoms after induction of detrusor overactivity in mice1.
    Acta cirurgica brasileira, 2019, Feb-28, Volume: 34, Issue:2

    To evaluate the impact of the combination of BRL 37344 and tadalafil (TDF) on the reduction of overactive bladder (OB) symptoms.. Thirty mice were randomized into 5 groups (G) of 6 animals each. L-NAME was used to induce DO. G1: Control; G2: L-NAME; G3: L-NAME + TDF; G4: L-NAME + BRL 37344; G5: L-NAME + TDF + BRL 37344. After 30 days of treatment, the animals were submitted to cystometry to evaluate non-voiding contractions (NVC), threshold pressure (TP), baseline pressure (BP), frequency of micturition (FM) and threshold volume (TV). Differences between the groups were analyzed with ANOVA followed by the Tukey test.. NVC increased in G2 (4.33±2.58) in relation to G1 (1.50±0.55). NVC decreased in G3 (2.00±1.10), G4 (1.50±1.52) and G5 (2.00±1.26) compared to G2 (p<0.05). FM decreased in G3 (0.97±0.71), G4 (0.92±0.38) and G5 (1.05±0.44) compared to G2 (p<0.05). However, the combination of TDF and BRL37344 was not more effective at increasing NVC and improving FM than either drug alone. The five groups did not differ significantly with regard to TV.. The combination of BRL 37344 and TDF produced no measurable additive effect on reduction of OB symptoms.

    Topics: Animals; Disease Models, Animal; Drug Therapy, Combination; Ethanolamines; Male; Mice; NG-Nitroarginine Methyl Ester; Random Allocation; Tadalafil; Urinary Bladder, Overactive; Urination; Urological Agents

2019
Effect of co-administration of two different phosphodiesterase inhibitors and a β
    European journal of pharmacology, 2018, Aug-15, Volume: 833

    The purpose of this study was to evaluate in vitro the effect of the combination of BRL 37344 (ß

    Topics: Adrenergic beta-3 Receptor Agonists; Animals; Disease Models, Animal; Drug Evaluation, Preclinical; Drug Synergism; Drug Therapy, Combination; Ethanolamines; Humans; Male; Mice; Muscle Contraction; Muscle Relaxation; Muscle, Smooth; NG-Nitroarginine Methyl Ester; Phosphodiesterase 4 Inhibitors; Phosphodiesterase 5 Inhibitors; Rolipram; Tadalafil; Treatment Outcome; Urinary Bladder; Urinary Bladder, Overactive

2018
The effect of combined treatment with a β
    Neurourology and urodynamics, 2017, Volume: 36, Issue:3

    The objective of the study was to evaluate the efficacy and safety of the combined treatment with the β. The ROCK inhibitor (GSK 269962) and/or the β. The combined use of GSK 269962 and BRL 37344 in doses ineffective in monotherapies, ameliorated DO. An increase was found in voided volume, voiding efficiency, volume threshold, intercontraction interval, bladder compliance, and volume threshold to elicit nonvoiding contractions, accompanied by a decrease in basal pressure, threshold pressure, detrusor overactivity index, nonvoiding contractions amplitude, and frequency. The combination therapy in question proved to have no effect on micturition voiding pressure, post-void residual, bladder contraction duration, or relaxation time. A 24 hr observation of female rats who received GSK 269962 and/or BRL 37344 did not show any significant changes in urine production. BRL 37344 increased heart rate and blood pressure proportionately to the applied dose. The assessment of the combined treatment with GSK 269962 and BRL 37344 revealed a significant drop of cardiovascular parameters when compared to the rats which only received BRL 37344.. The combined use of β. This polytherapy appears to improve urine storage with no impairment of voiding function. Neurourol. Urodynam. 36:580-588, 2017. © 2016 Wiley Periodicals, Inc.

    Topics: Animals; Arterial Pressure; Disease Models, Animal; Drug Therapy, Combination; Ethanolamines; Female; Heart Rate; Imidazoles; Oxadiazoles; Rats; Rats, Wistar; Treatment Outcome; Urinary Bladder; Urinary Bladder, Overactive; Urination; Urological Agents

2017
Modulation of musculoskeletal hyperalgesia by brown adipose tissue activity in mice.
    Pain, 2016, Volume: 157, Issue:11

    Cold exposure and a variety of types of mild stress increase pain in patients with painful disorders such as fibromyalgia syndrome. Acutely, stress induces thermogenesis by increasing sympathetic activation of beta-3 (β3) adrenergic receptors in brown adipose tissue. Chronic stress leads to the hypertrophy of brown adipose, a phenomenon termed adaptive thermogenesis. Based on the innervation of skeletal muscle by collaterals of nerves projecting to brown adipose, we theorized an association between brown adipose tissue activity and musculoskeletal hyperalgesia and tested this hypothesis in mice. Exposure to a cold swim or injection of BRL37344 (β3 adrenergic agonist) each enhanced musculoskeletal hyperalgesia, as indicated by morphine-sensitive decreases in grip force responses, whereas SR59230A (β3 adrenergic antagonist) attenuated swim-induced hyperalgesia. Chemical ablation of interscapular brown adipose, using Rose Bengal, attenuated the development of hyperalgesia in response to either swim stress or BRL37344. In addition, elimination of the gene expressing uncoupling protein-1 (UCP1), the enzyme responsible for thermogenesis, prevented musculoskeletal hyperalgesia in response to either a swim or BRL37344, as documented in UCP1-knockout (UCP1-KO) mice compared with wild-type controls. Together, these data provide a convergence of evidence suggesting that activation of brown adipose contributes to stress-induced musculoskeletal hyperalgesia.

    Topics: Adipose Tissue, Brown; Adrenergic beta-Agonists; Animals; Body Temperature; Body Weight; Cold Temperature; Disease Models, Animal; Ethanolamines; Female; Hyperalgesia; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle Strength; Musculoskeletal Pain; Pain Threshold; Reaction Time; Swimming; Tail; Uncoupling Protein 1

2016
β3 adrenergic receptor selective stimulation during ischemia/reperfusion improves cardiac function in translational models through inhibition of mPTP opening in cardiomyocytes.
    Basic research in cardiology, 2014, Volume: 109, Issue:4

    Selective stimulation of β3 adrenergic-receptor (β3AR) has been shown to reduce infarct size in a mouse model of myocardial ischemia/reperfusion. However, its functional long-term effect and the cardioprotective mechanisms at the level of cardiomyocytes have not been elucidated, and the impact of β3AR stimulation has not been evaluated in a more translational large animal model. This study aimed at evaluating pre-perfusion administration of BRL37344 both in small and large animal models of myocardial ischemia/reperfusion. Pre-reperfusion administration of the β3AR agonist BRL37344 (5 μg/kg) reduced infarct size at 2-and 24-h reperfusion in wild-type mice. Long-term (12-weeks) left ventricular (LV) function assessed by echocardiography and cardiac magnetic resonance (CMR) was significantly improved in β3AR agonist-treated mice. Incubation with β3AR agonist (BRL37344, 7 μmol/L) significantly reduced cell death in isolated adult mouse cardiomyocytes during hypoxia/reoxygenation and decreased susceptibility to deleterious opening of the mitochondrial permeability transition pore (mPTP), via a mechanism dependent on the Akt-NO signaling pathway. Pre-reperfusion BRL37344 administration had no effect on infarct size in cyclophilin-D KO mice, further implicating mPTP in the mechanism of protection. Large-white pigs underwent percutaneous coronary ischemia/reperfusion and 3-T CMR at 7 and 45 days post-infarction. Pre-perfusion administration of BRL37344 (5 μg/kg) decreased infarct size and improved long-term LV contractile function. A single-dose administration of β3AR agonist before reperfusion decreased infarct size and resulted in a consistent and long-term improvement in cardiac function, both in small and large animal models of myocardial ischemia/reperfusion. This protection appears to be executed through inhibition of mPTP opening in cardiomyocytes.

    Topics: Adrenergic beta-3 Receptor Agonists; Animals; Cardiotonic Agents; Cell Death; Cyclophilins; Disease Models, Animal; Ethanolamines; Magnetic Resonance Imaging; Male; Mice, Knockout; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Myocardial Infarction; Myocardial Reperfusion Injury; Myocytes, Cardiac; Nitric Oxide; Peptidyl-Prolyl Isomerase F; Proto-Oncogene Proteins c-akt; Receptors, Adrenergic, beta-3; Signal Transduction; Swine; Time Factors; Ventricular Function, Left

2014
Heart rate variability after BRL37344, a beta-3 agonist, in experimental bladder outlet obstruction.
    Postepy higieny i medycyny doswiadczalnej (Online), 2013, Aug-12, Volume: 67

    Bladder overactivity symptoms accompany benign prostatic hyperplasia (BPH) syndrome. The autonomic nervous system (ANS) disturbances may be involved in bladder dysfunction. An ameliorating effect on bladder overactivity is being assigned to the currently investigated β-3 adrenoreceptor agonists. However, little is known about the influence of β-3 agonists on ANS activity. The aim of our study was to estimate ANS activity using heart rate variability (HRV) in experimental model of bladder outlet obstruction (BOO), reflecting human BPH.. 30 female rats, divided into control, non-treated BOO (LLBOO), and β-3 agonist (BRL37344) BOO treated (LLBOO+β3 agonist) were studied. BOO was evoked by 5-week long partial proximal urethra ligation. Next, 20-minute resting HRV recordings were performed in each of the studied groups following i.p. administration of the vehicle (LLBOO) or BRL37344 (LLBOO+β3 agonist).. LLBOO rats were characterized by diminished NN range, SDNN, and rMSSD in time-domain analysis. Similarly, TP and non-normalized spectral HRV parameters were also decreased. Contrary to these findings, normalized spectral parameters were lower (nLF) and higher (nHF). The animals treated with BRL37344 demonstrated no significant differences in time--domain HRV parameters. In spectral analysis, a decrease in LF and HF, together with a fall in TP, was found. Moreover, both nLF and nHF reached almost the same values in control and β-3 agonist treated rats. DISSCUSSION: Our data indicates that BRL37344 is an agent abolishing the autonomic imbalance in experimental BOO, which may contribute to relieving the symptoms of bladder overactivity in β-3 agonists treated participants.

    Topics: Adrenergic beta-Agonists; Animals; Autonomic Nervous System; Disease Models, Animal; Ethanolamines; Female; Heart Rate; Male; Organ Size; Prostatic Hyperplasia; Rats; Rats, Wistar; Urinary Bladder; Urinary Bladder Neck Obstruction; Urinary Bladder, Overactive

2013
Beta3-adrenoceptors in the rat sacral spinal cord and their functional relevance in micturition under normal conditions and in a model of partial urethral obstruction.
    Neurourology and urodynamics, 2011, Volume: 30, Issue:7

    Beta3-adrenoceptor selective agonists are evaluated as a new treatment for patients with lower urinary tract symptoms . It is believed that β3-AR selective agonists exert their effects via a peripheral site of action. However, β3-ARs have been found in brain tissue. This study examined whether β3-ARs are present in rat sacral spinal cord, and whether there are differences in β3-AR expression between normal and partial urethral obstruction (PUO) animals, and furthermore assessed the functional relevance of spinal β3-ARs for micturition.. Thirty-eight male Sprague-Dawley rats underwent either PUO or sham-operation. Two weeks after operation, half of the animals were used for histomorphological analysis. Remaining animals were used for functional experiments, where a β3-AR selective agonist, BRL 37344, was given intrathecally. Bladder function was assessed by continuous cystometry in non-anesthetized animals before and after drug administration.. Beta3-ARs were found in sacral spinal cord segments with an accumulation in the ventral horn. There was a significant increase of β3-AR expression in obstructed rats. In functional experiments obstructed rats showed increased bladder weight, micturition frequency, spontaneous activity, and bladder pressures (all P < 0.05) compared to controls. Intrathecally administered BRL 37344 showed no effect in non-obstructed rats. In obstructed rats intrathecal BRL 37344 significantly reduced bladder pressures, spontaneous activity, and micturition frequency (all P < 0.05).. Beta3-ARs are present in rat sacral spinal cord, and are significantly up-regulated after PUO. Besides their well-established peripheral site of action in the treatment of voiding dysfunction, β3-AR selective agonists might exert relevant effects at a central nervous site of action.

    Topics: Adrenergic beta-3 Receptor Agonists; Animals; Blotting, Western; Disease Models, Animal; Ethanolamines; Immunohistochemistry; Male; Pilot Projects; Rats; Rats, Sprague-Dawley; Receptors, Adrenergic, beta-3; Sacrum; Spinal Cord; Time Factors; Up-Regulation; Urethral Obstruction; Urinary Bladder; Urination; Urodynamics

2011
Lateral paracapsular GABAergic synapses in the basolateral amygdala contribute to the anxiolytic effects of beta 3 adrenoceptor activation.
    Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 2010, Volume: 35, Issue:9

    Norepinephrine (NE) is known to play an integral role in the neurobiological response to stress. Exposure to stressful stimuli increases NE levels in brain regions that regulate stress and anxiety, like the basolateral amygdala (BLA). NE is thought to increase excitability in these areas through alpha- and beta-adrenoceptors (ARs), leading to increased anxiety. Surprisingly, recent studies have shown that systemic beta 3-AR agonist administration decreases anxiety-like behaviors, suggesting that beta 3-ARs may inhibit excitability in anxiety-related brain regions. Therefore, in this study we integrated electrophysiological and behavioral approaches to test the hypothesis that the anxiolytic effects of beta 3-AR agonists may be mediated by an increase in BLA GABAergic inhibition. We examined the effect of a selective beta 3-AR agonist, BRL37344 (BRL), on GABAergic synapses arising from local circuit interneurons and inhibitory synapses originating from a recently described population of cells called lateral paracapsular (LPCS) interneurons. Surprisingly, BRL selectively enhanced LPCS-evoked inhibitory postsynaptic currents (eIPSCs) with no effect on local GABAergic inhibition. BRL also had no effect on glutamatergic synaptic excitation within the BLA. BRL potentiation of LPCS eIPSCs was blocked by the selective beta 3-AR antagonist, SR59230A, or by intracellular dialysis of Rp-CAMPS (cAMP-dependent protein kinase inhibitor), and this enhancement was not associated with any changes in spontaneous IPSCs or LPCS paired-pulse ratio. BRL also increased the amplitude of unitary LPCS IPSCs (uIPSCs) with no effect on uIPSC failure rate. Finally, bilateral BLA microinjection of BRL reduced anxiety-like behaviors in an open-field assay and the elevated plus-maze. Collectively, these data suggest that beta 3-AR activation selectively enhances LPCS, but not local, BLA GABAergic synapses, and that increases in LPCS-mediated inhibition may contribute to the anxiolytic profile of beta 3-AR agonists.

    Topics: Adrenergic beta-Agonists; Adrenergic beta-Antagonists; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; Amygdala; Animals; Anxiety; Behavior, Animal; Cyclic AMP; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Ethanolamines; Evoked Potentials; Excitatory Amino Acid Agonists; Excitatory Amino Acid Antagonists; Exploratory Behavior; GABA Antagonists; gamma-Aminobutyric Acid; Inhibitory Postsynaptic Potentials; Interneurons; Locomotion; Male; Microinjections; Morpholines; Patch-Clamp Techniques; Propranolol; Protein Kinase Inhibitors; Rats; Rats, Sprague-Dawley; Receptors, Adrenergic, beta-3; Synapses; Thionucleotides

2010
β(3) adrenergic stimulation of the cardiac Na+-K+ pump by reversal of an inhibitory oxidative modification.
    Circulation, 2010, Dec-21, Volume: 122, Issue:25

    inhibition of L-type Ca(2+) current contributes to negative inotropy of β(3) adrenergic receptor (β(3) AR) activation, but effects on other determinants of excitation-contraction coupling are not known. Of these, the Na(+)-K(+) pump is of particular interest because of adverse effects attributed to high cardiac myocyte Na(+) levels and upregulation of the β(3) AR in heart failure.. we voltage clamped rabbit ventricular myocytes and identified electrogenic Na(+)-K(+) pump current (I(p)) as the shift in holding current induced by ouabain. The synthetic β(3) AR agonists BRL37344 and CL316,243 and the natural agonist norepinephrine increased I(p). Pump stimulation was insensitive to the β(1)/β(2) AR antagonist nadolol and the protein kinase A inhibitor H-89 but sensitive to the β(3) AR antagonist L-748,337. Blockade of nitric oxide synthase abolished pump stimulation and an increase in fluorescence of myocytes loaded with a nitric oxide-sensitive dye. Exposure of myocytes to β(3) AR agonists decreased β(1) Na(+)-K(+) pump subunit glutathionylation, an oxidative modification that causes pump inhibition. The in vivo relevance of this was indicated by an increase in myocardial β(1) pump subunit glutathionylation with elimination of β(3) AR-mediated signaling in β(3) AR(-/-) mice. The in vivo effect of BRL37344 on contractility of the nonfailing and failing heart in sheep was consistent with a beneficial effect of Na(+)-K(+) pump stimulation in heart failure.. the β(3) AR mediates decreased β(1) subunit glutathionylation and Na(+)-K(+) pump stimulation in the heart. Upregulation of the receptor in heart failure may be a beneficial mechanism that facilitates the export of excess Na(+).

    Topics: Adrenergic beta-Agonists; Adrenergic beta-Antagonists; Animals; Dioxoles; Disease Models, Animal; Ethanolamines; Glutathione; Heart Failure; Mice; Mice, Knockout; Myocardial Contraction; Myocytes, Cardiac; Nadolol; Oxidative Stress; Patch-Clamp Techniques; Rabbits; Receptors, Adrenergic, beta-3; Sheep; Sodium; Sodium-Potassium-Exchanging ATPase

2010
Sepsis is associated with an upregulation of functional beta3 adrenoceptors in the myocardium.
    European journal of heart failure, 2007, Volume: 9, Issue:12

    To analyze the implication of the beta3-adrenoceptor (beta3-AR) pathway in human septic myocardium and a murine model of sepsis, a condition associated with myocardial depression.. beta3-AR and eNOS protein abundance were increased (332+/-66.4% and 218+/-39.3; P<0.05) in hearts from septic patients. The effect of BRL37344, a beta3-AR-preferential agonist, was analyzed by videomicroscopy on the contractility of neonatal mouse ventricular myocytes (NMVM) incubated with conditioned medium from LPS-stimulated cultured macrophages (Mc-LPS+ medium). Stimulation of untreated NMVM with BRL37344 dose-dependently decreased the amplitude of contractile shortening (P<0.05). This response was abolished by L-NAME (NOS inhibitor). Incubation in Mc-LPS+ medium potentiated the depressing effect of BRL37344 (P<0.05) as well as of SR58611A (P<0.05) in wild-type myocytes. Importantly, the contractile depression was abrogated in cardiomyocytes from beta3-AR KO mice.. beta3-AR are upregulated during sepsis in the human myocardium and by cytokines in murine cardiomyocytes, where they mediate an increased negative inotropic response to beta3 agonists. Activation of the beta3-AR pathway by catecholamines may contribute to the myocardial dysfunction in sepsis.

    Topics: Adrenergic beta-3 Receptor Agonists; Adrenergic beta-Agonists; Adult; Animals; Animals, Newborn; Blotting, Western; Cells, Cultured; Culture Media, Conditioned; Disease Models, Animal; Ethanolamines; Humans; Male; Mice; Mice, Inbred C57BL; Middle Aged; Myocardial Contraction; Myocytes, Cardiac; Rats; Rats, Wistar; Receptors, Adrenergic, beta-3; Reverse Transcriptase Polymerase Chain Reaction; RNA; Sepsis; Stereoisomerism; Up-Regulation

2007
Proinflammatory role of leptin in experimental colitis in rats benefit of cholecystokinin-B antagonist and beta3-agonist.
    Life sciences, 2001, Jun-22, Volume: 69, Issue:5

    Leptin, a hormone primarily secreted from adipocytes, plays a key role in controlling body weight homeostasis. In vitro studies indicate that it is also implicated in immune responses. Hyperleptinaemia has been reported in acute inflammation, especially during the early stages of intestinal inflammation in rats. The present study investigated the possible role of leptin in the pathogenesis of trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats. Since no specific antagonist of leptin is available, a CCK-B antagonist (YM022) and a beta3 agonist (BRL37344) were used in this study to inhibit leptin secretion. Colitis was induced by intracolonic instillation of TNBS in rats. Five TNBS-groups were subcutaneously implanted with micropumps containing: placebo, YM022, BRL37344, BRL37344 and exogenous leptin simultaneously, or leptin alone. At sacrifices, colitis severity was assessed by macroscopic and histological scoring systems and by determination of tissue myeloperoxidase activity. The TNBS-induced hyperleptinaemia was significantly reduced by YM022 and BRL37344 (p<0.05). Inhibition of leptin secretion markedly reduced colonic inflammation, whatever the criteria considered (i.e. macroscopic, histological or biochemical). In contrast, administration of exogenous leptin completely abolished the beneficial effect of leptin-lowering drugs on colitis severity. These results provide the first direct evidence for an important deleterious role of leptin in the pathogenesis of experimental intestinal inflammation and suggest that a pro-inflammatory activity is attributable to leptin in vivo. Further studies are required to determine if these results have clinical significance.

    Topics: Adrenergic beta-3 Receptor Agonists; Adrenergic beta-Agonists; Analysis of Variance; Animals; Benzodiazepines; Colitis; Disease Models, Animal; Ethanolamines; Hormone Antagonists; Inflammatory Bowel Diseases; Leptin; Male; Rats; Rats, Wistar; Receptor, Cholecystokinin B; Receptors, Adrenergic, beta-3; Receptors, Cholecystokinin; Severity of Illness Index

2001
Upregulation of functional beta(3)-adrenergic receptor in the failing canine myocardium.
    Circulation research, 2001, Sep-28, Volume: 89, Issue:7

    Altered expression and functional responses to cardiac beta(3)-adrenergic receptors (ARs) may contribute to progressive cardiac dysfunction in heart failure (CHF). We compared myocyte beta(3)-AR mRNA and protein levels and myocyte contractile, [Ca(2+)](i) transient, and Ca(2+) current (I(Ca,L)) responses to BRL-37344 (BRL, 10(-8) mol/L), a selective beta(3)-AR agonist, in 9 instrumented dogs before and after pacing-induced CHF. Myocytes were isolated from left ventricular myocardium biopsy tissues. Using reverse transcription-polymerase chain reaction, we detected beta(3)-AR mRNA from myocyte total RNA in each animal. Using a cloned canine beta(3)-AR cDNA probe and myocyte poly A(+) RNA, we detected a single band about 3.4 kb in normal and CHF myocytes. beta(3)-AR protein was detected by Western blot. beta(3)-AR mRNA and protein levels were significantly greater in CHF myocytes than in normal myocytes. Importantly, these changes were associated with enhanced beta(3)-AR-mediated negative modulation on myocyte contractile response and [Ca(2+)](i) regulation. Compared with normal myocytes, CHF myocytes had much greater decreases in the velocity of shortening and relengthening with BRL accompanied by larger reductions in the peak systolic [Ca(2+)](i) transient and I(Ca,L). These responses were not modified by pretreating myocytes with metoprolol (a beta(1)-AR antagonist) or nadolol (a beta(1)- and beta(2)-AR antagonist), but were nearly prevented by bupranolol or L-748,337 (beta(3)-AR antagonists). We conclude that in dogs with pacing-induced CHF, beta(3)-AR gene expression and protein levels are upregulated, and the functional response to beta(3)-AR stimulation is increased. This may contribute to progression of cardiac dysfunction in CHF.

    Topics: Adrenergic beta-1 Receptor Antagonists; Adrenergic beta-2 Receptor Antagonists; Adrenergic beta-Agonists; Adrenergic beta-Antagonists; Animals; Blotting, Western; Calcium; Cardiac Pacing, Artificial; Cell Separation; Disease Models, Animal; Disease Progression; Dogs; Dose-Response Relationship, Drug; Enzyme Inhibitors; Ethanolamines; Heart Failure; Myocardial Contraction; Myocardium; Receptors, Adrenergic, beta-3; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Up-Regulation

2001