Β-adrenergic Blockers Research Articles

Microinjection of NMDA-neurotoxin into the superior salivatory nucleus of the rat: Short-term secretory and long-term drinking behavior effects

The anatomical location of the superior salivatory nucleus (SSN), the site of origin of the parasympathetic preganglionic cell bodies that innervate the submandibular-sublingual salivary glands, is well established in rats. However, as of yet there is no functional data that convincingly shows the secretory nature of this region. Previous studies have not been able to differentiate between interventions on efferent or afferent fibers connected to the SSN versus interventions on the salivatory nucleus itself. Taking advantage of the fact that salivatory neurons express NMDA-receptors on their somas, in the present study SSN cell bodies were activated and lesioned sequentially by means of intracerebral application of NMDA-neurotoxin. In exp. 1 two effects, a short- and a long-term effect, were observed following NMDA administration. The first effect was high submandibular-sublingual saliva secretion during the hour following administration of the neurotoxin and the second was a profound change in drinking behavior once the animals recovered from the lesion. Thus, on post-surgery days 16, 17 and 18, the rats exhibited hyperdipsia in the presence of dry food but not in the presence of wet food. In expt. 2 results showed that saliva hypersecretion observed after NMDA-microinjection was completely blocked by the administration of atropine (a cholinergic blocker) but not after the administration of dihydroergotamine plus propranolol (α and β-adrenergic blockers, respectively). From a functional perspective, these data suggest that the somata of the parvocellular reticular formation control the secretory activity of the submandibular-sublingual salivary glands and thus constitute the SSN.

Lipase catalyzed chemo-enzymatic synthesis of propranolol: A newer enzymatic approach

The biocatalytic processes are greener and safer alternatives for synthesis of drug and drug intermediates. This study reports one such approach of chemo-enzymatic synthesis of propranolol, a β-adrenergic receptor blocker. A green synthetic route was employed for synthesis of propranolol using enzymatic kinetic resolution. Racemic mixture of secondary alcohol [1-chloro-3-(naphthalen-1-yloxy)propan-2-ol] (RS)-5 was synthesized chemically in two step reaction and further its enzymatic kinetic resolution was carried out by using lipase to synthesize enantiomeric forms (R)-5 and S-(6) of propranolol. The kinetic resolution of (RS)-5 involves the transesterification of secondary racemic alcohol in which vinyl acetate is used as acyl donor. Initially, we screened commercially available lipases for kinetic resolution and of all the screened lipases Addzyme 001 showed the best results. The several reaction parameters such as organic solvent, acyl donor, temperature, reaction time and enzyme concentration were optimized to improve rate of reaction and to achieve maximum enantioselectivity. Addzyme 001 at 40 mg shows the maximum conversion rate of 49% using cyclohexane as the organic solvent, vinyl acetate as the acyl donor and it was found that the reaction yield was higher for (R)-5 along with the (S)-6 (eep = 98%, ees = 97%) at 40 °C in 48 h. Further, the treatment of (R)-5 with isopropyl amine resulted into formation of (S)-propranolol eep = 98%, and overall yield 29% independently. To synthesize (R)-propranolol, S-(6) acetate was produced enzymatically and was further deacylated by chemical hydrolysis for the production of (R)-propranolol. This study reports newer approach for synthesis of (R) and (S) propranolol using chemoenzymatic route.

Enantiocomplementary synthesis of β-adrenergic blocker precursors via biocatalytic nitration of phenyl glycidyl ethers

Enantiopure β-nitroalcohols, as an important class of nitro-containing compounds, are essential building blocks in pharmaceutical and organic chemistry, particularly for the synthesis of β-adrenergic blockers. In this study, we present the successful protein engineering of halohydrin dehalogenase HHDHamb for the enantioselective bio-nitration of various phenyl glycidyl ethers to the corresponding chiral β-nitroalcohols, using the inexpensive, commercially available, and safer nitrite as a nitrating agent. The chiral (R)- and (S)-1-nitro-3-phenoxypropan-2-ols were synthesized by the several enantiocomplementary HHDHamb variants through the whole-cell biotransformation, which showed good catalytic efficiency (up to 43% isolated yields) and high optical purity (up to >99% ee). In addition, we also demonstrated that the bio-nitration method was able to tolerate the substrate at a high concentration of 1000 mM (150 g/L). Furthermore, representative synthesis of two optically active enantiomers of the β-adrenergic blocker metoprolol was successfully achieved by utilizing the corresponding chiral β-nitroalcohols as precursors.

<i>NOS2</i>, <i>NOS3</i>, <i>SONE</i> gene transcripts levels in peripheral blood leukocytes and their relationship with markers of endothelial dysfunction in hypertension

Objective. The aim of the study was to evaluate the level of expression of the NOS2, NOS3, SONE genes in peripheral blood leukocytes (PBL) of patients with hypertension (HTN) and to study the relationship between the level of transcripts of these genes and the content of nitric oxide metabolites and markers of endothelial dysfunction.Design and methods. The study included healthy people (25 people) and patients with HTN (stages I–II) before prescribing antihypertensive drugs (15 people) and taking cardioselective β-adrenergic receptor blockers for more than a year (metoprolol (25 mg per day) or bisoprolol (5–10 mg per day)) (20 people). The level of gene transcripts was assessed by real-time polymerase chain reaction (PCR). The level of nitric oxide metabolites was determined by the colorimetric method using the Griess reagent. The content of asymmetric dimethylarginine (ADMA), soluble forms of vascular cell adhesion molecule (sVCAM), and intercellular adhesion molecule (sICAM) in blood plasma was determined by ELISA. The content of malondialdehyde (MDA) in blood plasma was determined spectrophotometrically by color reaction with thiobarbituric acid. Statistical processing of the results was carried out using the Statgraphics Centurion XVI software package (version 16.1.11).Results. The level of nitric oxide metabolites in the blood plasma of HTN patients without antihypertensive therapy was 2,1 times higher than in healthy individuals (p = 0,001) and 1,7 times higher than in patients with HTN taking metoprolol or bisoprolol (p = 0,002). The relative content of mRNA of the NOS3 gene in PBL of individuals included in the study did not differ (p > 0,05). The level of NOS2 gene transcripts in PBL of HTN patients before the prescription of antihypertensive drugs exceeded that in healthy individuals (p = 0,0009) and in HTN patients taking metoprolol or bisoprolol (p = 0,0002). The number of SONE transcripts in the PBL of HTN patients was higher than in people with normal blood pressure (p < 0,00001 when comparing patients before the prescription of antihypertensive therapy and individuals from the control group; p = 0,04 when comparing patients with HTN taking antihypertensive drugs and normotensive subjects). The content of MDA, ADMA, sVCAM was higher in the plasma of HTN patients without antihypertensive therapy compared with people from the control group (p = 0,005, 0,003, 0,039, respectively) and patients taking metoprolol or bisoprolol (p = 0,0006, 0,019, 0,016, respectively). The content of nitric oxide metabolites positively correlated with NOS2, SONE, VCAM1 mRNA level in PBL, the content of MDA and ADMA in blood plasma (p < 0,05). A positive correlation was found between the concentration of MDA and ADMA in plasma (p = 0,03).Conclusions. An increase in the level of nitric oxide metabolites in HTN is associated with an increase in the transcriptional activity of the NOS2 gene, a disturbance of the redox balance of the body, and the development of endothelial dysfunction. The SONE gene is probably involved in the modulation of nitric oxide levels in HTN not only as an antisense transcript that destabilizes the mRNA of the NOS3 gene in vascular endothelial cells, but also indirectly, namely, through the regulation of homeostasis of immune system cells through autophagy.

B1-adrenergic blockers preserve motor function by inhibiting the production of extracellular traps

Sepsis is characterized by a dysregulated host response to an infection, potentially leading to fatal organ dysfunctions. Among these organs, the central nervous system (CNS) is particularly affected with encephalopathies associated or not with chronic disabling pain. These symptoms are caused by broad neuroinflammation with activation of resident microglia cells and infiltration of leukocytes, especially neutrophils. These immune cells have the ability to produce extracellular traps (ETs) in blood and tissues. These components are composed of chromatins and various antimicrobial proteins, and its role is to capture and destroy pathogens. However, in case of excessive production, deleterious effects occur such as tissue damage and reduction of neuronal excitability.In this study, the objectives were: 1) to determine whether in a model of endotoxemic shock, neutrophils and microglia form ETs in the CNS; 2) and to determine if a modulation of ETs production was beneficial on neuromuscular disorders associated with endotoxemic shock.We observed an infiltration of neutrophils in the SNC, an activation of microglia and a production of ETs following intraperitoneal lipopolyssacharide (LPS) administration in mice (adult Swiss male, 30-45g). Atenolol, a β1-adrenergic blocker with intrinsic immunomodulatory properties, significantly decreases the production of ETs associated in both microglia and neutrophils (citrullinated histone H3: 279.1 ± 101.9 MFI versus 117.1 ± 77.21 MFI, p<0,01). In addition, this treatment preserved the gastrocnemius motoneurons excitability (39,93 ± 15,16 mV in control group, 8.147 ± 5.892 mV in LPS group and 27.32 ± 10.73 mV in LPS+atenolol group). Similar results have been observed when the production of ETs was prevented by using sivelestat (inhibitor of extracellular traps).In conclusion, our results demonstrate that sepsis increases neutrophil infiltration into the spinal cord, activates immune cells and produces extracellular traps that directly impair motor function. Prevention of ETs formation partly restores motor function and could be a good target in order to reduce adverse effects in sepsis but also in other motor related pathologies. This work was supported by funding from the Chancellerie des Universites de Paris (Legs Poix), INSERM and Paris-Saclay University-UVSQ. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

B1-adrenergic blockers provide cardiac protection through extracellular traps inhibition during widespread inflammation

Sepsis is one of the leading causes of death worldwide, and no therapy is available other than intensive care treatments. Drug development attempts have mainly focused on controlling inflammation or treating dysfunction, without significant improvement in the last decades. Recently, interest has emerged in β1-adrenergic blockade, which has proved beneficial to both parameters. Unfortunately, the specific underlying mechanisms have not been addressed yet. Our study aimed to investigate on mice (adult Swiss male, 30-45g) lipopolyssacharide or cecal ligature and puncture models the effects of atenolol, a β1-adrenergic blocker, currently used in intensive care units for hypertension and arrhythmia. The results demonstrated a beneficial effect of treatment on survival and a preservation of cardiac function including left ventricular ejection fraction (33±2,8% in sepsis group versus 55±5,1% in sepsis-treated group, p<0,05) at a concentration reducing heart rate by approximately 10%.We wondered if beneficial results obtained with atenolol could be due to a modulation of extracellular traps. These components are essential in pathogen spreading control and are increased during sepsis. However, an excess of their production induces vascular occlusions and acute heart injuries.We demonstrated that neutrophils extracellular traps were increased in heart and blood during sepsis and decreased significantly following atenolol administration (blood: 1.1±0,3% in control group, 13,4±1.8% in sepsis group, 6.9±1.2% in sepsis-treated group). This beneficial effect of atenolol was not associated with other modulations of neutrophil function such as their ability to phagocyte (33,6±3,9% in sepsis group versus 25.6±3.6% in sepsis-treated group, p>0,05), to undergo apoptosis (Annexin V+/ L/D-: 13,2±2.1% in sepsis group versus 14.1±2.9% in sepsis-treated group, p>0,05) or to degranulate. Blood neutrophil phenotypes associated with their maturation state (expression of CD62L and CXCR2) or ability to migrate into tissue (expression of adhesion molecules PSGL1, LFA1, VLA4, PECAM1) was also similar between LPS and LPS-treated groups. Although, the modulation of extracellular traps production by atenolol was also observed in other immune cells population able to extrude chromatin fibers in extracellular space such as macrophages. These results suggest a specific beneficial effect of ß1-adrenergic blockers on extracellular traps formation associated with cardiac function preservation and ultimately survival without detrimental effect on heart rate during widespread inflammation. This work was supported by funding from INSERM and Paris-Saclay University-UVSQ. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Enantioseparation, quantification, molecular docking and molecular dynamics study of five β-adrenergic blockers on Lux-Cellulose-2 column

Enantioseparation of five β-adrenergic blockers was studied using two mobile phases on a cellulose tris(3‐chloro‐4‐methylphenylcarbamate) (Lux-Cellulose-2) chiral column in normal phase mode. The first mobile phase composed of n-hexane: ethanol: diethylamine 60: 40: 0.1 by volume has successfully resolved the chromatographic peaks of three pairs of β-adrenergic blockers namely, bisoprolol, carvedilol and atenolol. A mixture of n-hexane: ethanol: diethyl amine 75: 25: 0.1 by volume was used as the second mobile phase to separate the four pairs of enantiomers, metoprolol, carvedilol, nebivolol and atenolol with high resolution values. The mobile phases were pumped at a flow rate 1 mL/min with column temperature 25 °C using a UV detector at 230 nm. Molecular docking simulations of the five pairs of enantiomers was carried out in the cavities of the chiral stationary phase to gain a better understanding of the interaction between analyte enantiomers and chiral stationary phase and to better understand the mechanism of chiral recognition. According to the results, hydrogen bond interactions and π-π- interactions were the main types of interaction involved in the chiral recognition. Molecular dynamics simulation was performed to investigate the solvent effect on the interaction of the five pair of enantiomers in the chiral stationary phase cavity under dynamic conditions.

The β1 Adrenergic Blocker Nebivolol Ameliorates Development of Endotoxic Acute Lung Injury

Acute lung injury (ALI) is a disease, with no effective treatment, which might result in death. Formations of excessive inflammation and oxidative stress are responsible for the pathophysiology of ALI. Nebivolol (NBL), a third-generation selective β1 adrenoceptor antagonist, has protective pharmacological properties, such as anti-inflammatory, anti-apoptotic, and antioxidant functions. Consequently, we sought to assess the efficacy of NBL on a lipopolysaccharide (LPS)-induced ALI model via intercellular adhesion molecule-1 (ICAM-1) expression and the tissue inhibitor of metalloproteinases-1 (TIMP-1)/matrix metalloproteinases-2 (MMP-2) signaling. Thirty-two rats were split into four categories: control, LPS (5 mg/kg, intraperitoneally [IP], single dose), LPS (5 mg/kg, IP, one dosage 30 min after last NBL treatment), + NBL (10 mg/kg oral gavage for three days), and NBL (10 mg/kg oral gavage for three days). Six hours after the administration of LPS, the lung tissues of the rats were removed for histopathological, biochemical, gene expression, and immunohistochemical analyses. Oxidative stress markers such as total oxidant status and oxidative stress index levels, leukocyte transendothelial migration markers such as MMP-2, TIMP-1, and ICAM-1 expressions in the case of inflammation, and caspase-3 as an apoptotic marker, significantly increased in the LPS group. NBL therapy reversed all these changes. The results of this study suggest that NBL has utility as a potential therapeutic agent to dampen inflammation in other lung and tissue injury models.

INTEGRATIVE AND BIOCHEMICAL PARAMETERS IN RATS IN THE SIMULATION OF DOXORUBICIN CHRONIC HEART FAILURE AND DURING THE USE OF Β-ADRENERGIC BLOCKERS

β-adrenergic blockers have been actively used in the treatment of heart failure, which relieve excessive sympathetic stimulation of the myocardium, reduce calcium overload of cardiomyocytes, reduce the heart's oxygen demand, inhibit lipid peroxidation and stabilize cell membranes, have an antiarrhythmic effect. The aim: to compare efficiency of various drugs with new potential "Hypertril" in the conditions of modeling doxorubicin chronic heart failure (CHF) to improve parameters. Objective: CHF was modeled on 85 white outbred rats weighing 190–220g by administering doxorubicin at a cumulative dose of 15 mg/kg. Material and metods: Nebivalol, Carvedilol, Bisoprolol, Metoprolol and Hypertril were administered intragastrically once a day in the form of a suspension of 1% starch mucus for 30 days after a 14-day administration of doxorubicin. To determine damage, we used the solid-phase immunosorbent sandwich ELISA method, enzyme immunoassay and the immunoturbodimetric method. Result and discussion: Administration of Hypertril to rats with CHF led to a decrease in the blood of the main molecular markers of CHF to the values of intact animals, which indicated its significant cardioprotective effect in comparison with other drugs. Hypertril reduces manifestations of mitochondrial dysfunction, protects the myocardium and positively affects the morphological and functional parameters of cardiomyocytes, inhibits apoptosis

The differences in the adrenergic receptors of proximal urethra between sexes.

The bladder and urethra work as a physiologically functional unit to facilitate continence in the storage and voiding phase. Sex differences have been found in the urethral contraction in response to α-adrenergic receptor activation. This study aimed to investigate the role of adrenergic receptors in the proximal urethra of male and female mice. Urinary bladder and proximal urethral smooth muscle (USM) samples from male and female C57BL/6 mice were isolated and mounted in an organ bath. Acetylcholine-induced contraction of the urinary bladder was compared in male and female mice. Phenylephrine and norepinephrine (NE) induced little contraction at a lower concentration, but a relaxing phase of female proximal USM was observed at a higher concentration. This contraction profile was inhibited by NG-nitro-L-arginine, lidocaine, and capsaicin. In addition, the NE-induced contraction was greater in the incubation of propranolol than that of L-NNA or lidocaine. These results suggested that the β-adrenoceptor may be the dominant receptor of female proximal USM, and the activity of calcitonin gene-related peptide sensory nerves and nitrergic nerves may pose an anti-contraction effect on the proximal urethra in female mice. β-adrenoceptor may be the dominant receptor of female proximal USM. The use of β-adrenergic receptor blocker agents might have the potential for the treatment of female voiding dysfunction.

Propranolol Modulates Cerebellar Circuit Activity and Reduces Tremor.

Tremor is the most common movement disorder. Several drugs reduce tremor severity, but no cures are available. Propranolol, a β-adrenergic receptor blocker, is the leading treatment for tremor. However, the in vivo circuit mechanisms by which propranolol decreases tremor remain unclear. Here, we test whether propranolol modulates activity in the cerebellum, a key node in the tremor network. We investigated the effects of propranolol in healthy control mice and Car8wdl/wdl mice, which exhibit pathophysiological tremor and ataxia due to cerebellar dysfunction. Propranolol reduced physiological tremor in control mice and reduced pathophysiological tremor in Car8wdl/wdl mice to control levels. Open field and footprinting assays showed that propranolol did not correct ataxia in Car8wdl/wdl mice. In vivo recordings in awake mice revealed that propranolol modulates the spiking activity of control and Car8wdl/wdl Purkinje cells. Recordings in cerebellar nuclei neurons, the targets of Purkinje cells, also revealed altered activity in propranolol-treated control and Car8wdl/wdl mice. Next, we tested whether propranolol reduces tremor through β1 and β2 adrenergic receptors. Propranolol did not change tremor amplitude or cerebellar nuclei activity in β1 and β2 null mice or Car8wdl/wdl mice lacking β1 and β2 receptor function. These data show that propranolol can modulate cerebellar circuit activity through β-adrenergic receptors and may contribute to tremor therapeutics.

Carvedilol exhibits anti-acute T lymphoblastic leukemia effect in vitro and in vivo via inhibiting β-ARs signaling pathway

An increasing number of studies have focus upon β-adrenergic receptor blockers and their anti-tumor effects. However, the use of Carvedilol (CVD), the third generation β-AR blocker, has not been explored for use against T-ALL. In this study, the level of β-ARs was explored in pediatric T-ALL patients. Moreover, the antitumor effects of CVD against T-ALL were assessed in vitro and in vivo, and the underlying mechanisms were investigated. The viability of T-ALL cells following CVD treatment was detected using a CCK-8 assay, and the apoptotic and cell cycle effects were measured using flow cytometry. The protein levels of β-ARs, cAMP, Epac, JAK2, STAT3, p-STAT3, PI3K, p-PI3K, AKT, p-AKT, mTOR, cyclin D1, PCNA, and cleaved caspase-3 were assessed by Western blotting. In vivo experiments were used to investigate the effect of CVD on T-ALL growth in mice. The results indicated that β-ARs were highly expressed in the newly diagnosed T-ALL cells when compared to those in the control group (P < 0.05). In vitro, CVD significantly inhibited T-ALL cell viability, promoted apoptosis and blocked the G0/G1 phase of cell cycle. After CVD treatment, the protein levels of β-ARs, cAMP, Epac, PI3K, p-PI3K, AKT, p-AKT, mTOR, JAK2, STAT3, p-STAT3, cyclin D1 and PCNA were significantly downregulated (P < 0.05); whereas cleaved caspase-3 was significantly upregulated (P < 0.05). In vivo, the volume and weight of the xenograft tumors were significantly decreased in the CVD group (P < 0.05). CVD promoted xenograft tumor apoptosis and reduced the proportion of CEM-C1 cells in murine peripheral blood and bone marrow (P < 0.05). Our results demonstrate that β-ARs are expressed in T-ALL. CVD has a strong antitumor effect against T-ALL and inhibits β-AR associated signaling pathways. Therefore, CVD may provide a potential therapy for T-ALL.

Shikonin reverses pyruvate kinase isoform M2-mediated propranolol resistance in infantile hemangioma through reactive oxygen species-induced autophagic dysfunction.

Infantile hemangioma (IH) is the most common benign tumor in infancy. Propranolol, a nonselective β-adrenergic receptor blocker, is now the first-line therapy for IH. Recently, low sensitivity to propranolol therapy has become one major reason for the failure of IH treatment. However, the exact underlying mechanisms are yet to be fully elucidated. Here, we reported that pyruvate kinase isoform M2 (PKM2), an essential glycolytic enzyme, played a critical role in regulating the progression of IH and the therapeutic resistance of propranolol treatment. Shikonin reversed the propranolol resistance in hemangioma-derived endothelial cells and in hemangioma animal models. Moreover, shikonin combined with propranolol could induce excessive reactive oxygen species (ROS) accumulation and lead to autophagic dysfunction, which is essential for the enhanced therapeutic sensitivity of propranolol treatment. Taken together, our results indicated that PKM2 has a significant role in hemangiomas progression and therapeutic resistance; it could be a safe and effective therapeutic strategy for those hemangiomas with poor propranolol sensitivity combined with shikonin.

470 Infantile hemangioma telocytes and noradrenaline are the prerequisite for response to propranolol

Propranolol, a nonselective β-adrenergic receptor blocker, is the first-line medical treatment for severe infantile hemangiomas (IH). We have shown in mice that propranolol-induced tumor growth inhibition was correlated with altered expression of Aquaporin-1 (AQP1), an aqueous channel modulated in angiogenesis and tumor cell migration. In IH, AQP1 made it possible to identify interstitial cell named telocytes (TC). TC are characterized by long cytoplasmic processes, the telopods, which form a three-dimensional communication network between cells, in organs such as skin, and in particular the dermal vessels.

Regulation of Cisplatin Resistance in Lung Cancer Cells by Nicotine, BDNF, and a β-Adrenergic Receptor Blocker.

It is well-recognized that cigarette smoking is a primary risk factor in the development of non-small cell lung cancer (NSCLC), known to account for ~80% of all lung cancers with nicotine recognized as the major addictive component. In investigating the effect of nicotine, brain-derived neurotrophic factor (BDNF), and the β-adrenergic receptor blocker, propranolol, on sensitivity of NSCLC cell lines, A549 and H1299, to cisplatin, we found increased cell viability, and enhanced cisplatin resistance with nicotine and/or BDNF treatment while opposite effects were found upon treatment with propranolol. Cell treatment with epinephrine or nicotine led to EGFR and IGF-1R activation, effects opposite to those found with propranolol. Blocking EGFR and IGF-1R activation increased cell sensitivity to cisplatin in both cell lines. PI3K and AKT activities were upregulated by nicotine or BDNF and downregulated by cell treatment with inhibitors against EGFR and IGF-1R and by propranolol. Apoptosis and cell sensitivity to cisplatin increased upon co-treatment of cells with cisplatin and inhibitors against PI3K or AKT. Our findings shed light on an interplay between nicotine, BDNF, and β-Adrenergic receptor signaling in regulating survival of lung cancer cells and chemoresistance which can likely expand therapeutic opportunities that target this regulatory network in the future.

SHOCK FROM NADOLOL OVERDOSE: THE FIRST REPORTED CASE OF SUCCESSFULLY TREATED WITH CONTINUOUS RENAL REPLACEMENT THERAPY (CRRT)

SHOCK FROM NADOLOL OVERDOSE: THE FIRST REPORTED CASE OF SUCCESSFULLY TREATED WITH CONTINUOUS RENAL REPLACEMENT THERAPY (CRRT)

Antihypertensive therapy of late arterial hypertension in children following successful coarctation correction.

Late arterial hypertension (AH) is the most significant complication of coarctation of the aorta (CoA). Only a few clinical studies described antihypertensive treatment of late AH following successful CoA repair. The primary objective of this multicentre cross-sectional study was to describe real-life antihypertensive therapy for late AH in children after hemodynamically successful CoA repair. The secondary objective was to describe antihypertensive therapy used within different haemodynamic phenotypes of AH. Blood pressure status, echocardiographic parameters and central blood pressure measurements were evaluated in 110 children aged 6-18 years following successful CoA repair with right arm blood pressure not exceeding leg blood pressure by at least 20 mmHg. AH was found in 62 (56%) patients including 47 who were already treated and 15 with new diagnosed AH of whom seven presented with masked hypertension. Among treated patients, 10 presented with masked hypertension. The dominant phenotype of AH among patients with uncontrolled AH was isolated systolic hypertension (32 patients out of 37; 87.5%). AH was controlled in 53% of treated patients. Fifty-three percent of hypertensive patients had elevated central SBP and 39% had left ventricular hypertrophy with various left ventricle geometry patterns, 23% of them had both. β-adrenergic receptor blockers were the most used antihypertensive drugs followed by angiotensin-converting enzyme inhibitors with doses within the lower recommended range. High prevalence of uncontrolled AH despite successful CoA repair and use of relatively low doses of antihypertensive drugs indicates the need of close blood pressure monitoring and more intensive and combined antihypertensive therapy.

β-ADRENERGIC RECEPTOR BLOCKERS AS A REGULATOR OF T CELL VIABILITY (IN THE MODEL SYSTEM OF THE JURKAT CELLS)

Our research aimed to establish the effectiveness of various β-adrenergic receptor blockers in the regulation of T cell proliferation in the model system of the Jurkat cells.Material and Methods. The research was conducted on the human leukemic mature T cells (Jurkat cells) (DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen (Germany)) activated by phytohemagglutinin (PHA). Viability and proliferative activity of intact and PHA-stimulated Jurkat cells under the influence of Nebilet, Egilok, Betalok Zok, and Propranolol were studied with the MTT test. Results. Study results show that β-adrenergic receptors blockers selectively influence the activity of mitochondrial dehydrogenases, and therefore viability in both intact and mitogen-stimulated Jurkat cells. In particular, Nebilet, Betalok Zok, and Propranolol induced a statistically significant decrease of intact Jurkat cells viability by 63%, 20%, and 32%, respectively; Egilok and Betalok Zok (25mg) didn’t statistically significantly affect the PHA- activated Jurkat cells viability. Nebilet, Betalok Zok (50 mg), and Propranolol decreased the viability of the mitogen (PHA) activated Jurkat cells (for PHA dose 20μg/ml) and didn’t affect at a PHA dose of 50μg/ml.

Beta-blocker use and urothelial bladder cancer survival: a Swedish register-based cohort study

Background Recent observational studies linked β-adrenergic receptor blocker use with improved survival in patients with several cancer types, but there is no information on the potential effects of β-blockers in patients with bladder cancer. Literature from pre-clinical studies is also limited, but urothelial cancer can exhibit significant overexpression of β-adrenergic receptors relative to normal urothelial tissue, suggesting that urothelial cancer may benefit from β-blockade therapy. We thus aimed to explore the possible association between β-blocker use and bladder cancer-specific mortality (BCSM) among patients with urothelial bladder cancer. Material and methods Patients diagnosed during 2006–2014 and identified from the Swedish Cancer Register (n = 16,669) were followed until 31 December 2015. Cox regression was used to evaluate the association of β-blockers dispensed within 90 days prior to cancer diagnosis with BCSM (primary outcome) and all-cause mortality, while controlling for socio-demographic factors, tumor characteristics, comorbidity, other medications and surgical procedures. Hazard ratios (HR) with 95% confidence intervals (CI) were reported. Results Overall, β-blocker use was associated with lower BCSM [HR 0.88 (95%CI 0.81–0.96)]. Especially use of nonselective β-blockers showed a clear inverse association in comparison with both nonuse [0.66 (0.50–0.86)] and use of other antihypertensive medications [0.72 (0.54–0.95)]. The inverse association was most pronounced among patients with locally advanced/metastatic disease: [0.35 (0.18–0.68)]. A lower-magnitude inverse association was observed for selective β-blocker use [0.91 (0.83–0.99)]. Largely similar inverse associations were observed for hydrophilic [0.82 (0.70–0.95)] and lipophilic [0.91 (0.83–1.00)] β-blocker use. Conclusion β-blocker use, particularly of the nonselective type, was associated with lower BCSM, especially in patients with locally advanced/metastatic urothelial bladder cancer.

Impact of R-Carvedilol on β2-Adrenergic Receptor-Mediated Spontaneous Calcium Release in Human Atrial Myocytes

A hallmark of atrial fibrillation is an excess of spontaneous calcium release events, which can be mimicked by β1- or β2-adrenergic stimulation. Because β1-adrenergic receptor blockers (β1-blockers) are primarily used in clinical practice, we here examined the impact of β2-adrenergic stimulation on spontaneous calcium release and assessed whether the R- and S-enantiomers of the non-selective β- blocker carvedilol could reverse these effects. For this purpose, human atrial myocytes were isolated from patients undergoing cardiovascular surgery and subjected to confocal calcium imaging or immunofluorescent labeling of the ryanodine receptor (RyR2). Interestingly, the β2-adrenergic agonist fenoterol increased the incidence of calcium sparks and waves to levels observed with the non-specific β-adrenergic agonist isoproterenol. Moreover, fenoterol increased both the amplitude and duration of the sparks, facilitating their fusion into calcium waves. Subsequent application of the non β-blocking R-Carvedilol enantiomer reversed these effects of fenoterol in a dose-dependent manner. R-Carvedilol also reversed the fenoterol-induced phosphorylation of the RyR2 at Ser-2808 dose-dependently, and 1 µM of either R- or S-Carvedilol fully reversed the effect of fenoterol. Together, these findings demonstrate that β2-adrenergic stimulation alone stimulates RyR2 phosphorylation at Ser-2808 and spontaneous calcium release maximally, and points to carvedilol as a tool to attenuate the pathological activation of β2-receptors.