• Title/Summary/Keyword: $\beta$-Blockers

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Characterization of Acetylcholine-induced Currents in Male Rat Pelvic Ganglion Neurons

  • Park, Joong-Hyun;Park, Kyu-Sang;Cha, Seung-Kyu;Lee, Keon-Il;Kim, Min-Jung;Park, Jong-Yeon;Kong, In-Deok;Lee, Joong-Woo
    • The Korean Journal of Physiology and Pharmacology
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    • v.8 no.4
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    • pp.219-225
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    • 2004
  • The pelvic ganglia provide autonomic innervations to the various urogenital organs, such as the urinary bladder, prostate, and penis. It is well established that both sympathetic and parasympathetic synaptic transmissions in autonomic ganglia are mediated mainly by acetylcholine (ACh). Until now, however, the properties of ACh-induced currents and its receptors in pelvic ganglia have not clearly been elucidated. In the present study, biophysical characteristics and molecular nature of nicotinic acetylcholine receptors (nAChRs) were studied in sympathetic and parasympathetic major pelvic ganglion (MPG) neurons. MPG neurons isolated from male rat were enzymatically dissociated, and ionic currents were recorded by using the whole cell variant patch clamp technique. Total RNA from MPG neuron was prepared, and RT-PCR analysis was performed with specific primers for subunits of nAChRs. ACh dose-dependently elicited fast inward currents in both sympathetic and parasympathetic MPG neurons $(EC_{50};\;41.4\;{\mu}M\;and\;64.0\;{\mu}M,\;respectively)$. ACh-induced currents showed a strong inward rectification with a reversal potential near 0 mV in current-voltage relationship. Pharmacologically, mecamylamine as a selective antagonist for ${\alpha}3{\beta}4$ nAChR potently inhibited the ACh-induced currents in sympathetic and parasympathetic neurons $(IC_{50};\;0.53\;{\mu}M\;and\;0.22\;{\mu}M,\;respectively)$. Conversely, ${\alpha}-bungarotoxin$, ${\alpha}-methyllycaconitine$, and $dihydro-{\beta}-erythroidine$, which are known as potent and sensitive blockers for ${\alpha}7$ or ${\alpha}4{\beta}2$ nAChRs, below micromolar concentrations showed negligible effect. RT-PCR analysis revealed that ${\alpha}3$ and ${\beta}4$ subunits were predominantly expressed in MPG neurons. We suggest that MPG neurons have nAChRs containing ${\alpha}3$ and ${\beta}4$ subunits, and that their activation induces fast inward currents, possibly mediating the excitatory synaptic transmission in pelvic autonomic ganglia.

Effect of Various Receptor Blockers on the Action of Adenosine Triphosphate on Uterine Smooth Muscle Motility in Immature Pig (미성숙 돼지 자궁 평활근의 운동성에 대한 Adenosine Triphosphate의 작용에 있어서 수종의 Receptor 차단제의 영향)

  • Kim, Joo-heon;Kwun, Jong-kuk;Kim, Yong-keun
    • Korean Journal of Veterinary Research
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    • v.27 no.2
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    • pp.201-206
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    • 1987
  • This study was carried out to investigate the action of ATP, which has been known as the neurotransmitter of noncholinergic- and nonadrenergic-nerve, on the motility of immature pig uterine smooth muscle. The results were summarized as follows; 1. The contraction and the contractile responses caused by ATP were increased in a dose-dependent manner between the concentration of ATP $10^{-6}M$ and $10^{-3}M$. The maximal contractile effect was appeared at the concentration of ATP $10^{-3}M$ and it was 70.2% of 100mM K contraction. 2. The contractile responses induced by ATP ($10^{-4}M$) were not blocked by the pretreatment with cholinergic receptor blocker, atropine ($10^{-6}M$). 3. The contractile responses induced by ATP ($10^{-4}M$) were not blocked by pretreatment with ${\alpha}$-adrenergic receptor blocker, phentolamine ($10^{-6}M$) and ${\beta}$-adrenergic receptor blocker, propranolol ($10^{-6}M$). 4. The contractile response induced by ATP ($10^{-4}M$) was not blocked by the pretreatment with $H_1-receptor$ blocker, pyrilamine ($10^{-6}M$) and $H_2-receptor$ blocker, cimetidine ($10^{-6}M$).

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Radiofrequency catheter ablation of atrioventricular nodal reentry tachycardia in children and adolescents: a single center experience

  • Hyun, Myung Chul
    • Clinical and Experimental Pediatrics
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    • v.60 no.12
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    • pp.390-394
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    • 2017
  • Purpose: Atrioventricular nodal reentry tachycardia (AVNRT) is less common in pediatric patients than in adult patients. Thus, data for pediatric AVNRT patients are insufficient. Hence, we aimed to analyze the patient characteristics, treatment, and any recurrences in pediatric AVNRT patients. Methods: We reviewed the records of 50 pediatric AVNRT patients who had undergone radiofrequency catheter ablation (RFCA) between January 1998 and December 2016 at a single regional center. The patients were aged ${\leq}18years$. Results: Among 190 pediatric patients who underwent RFCA for tachyarrhythmia, 50 (26.3%; mean age, $13.4{\pm}2.6years$) were diagnosed as having AVNRT by electrophysiological study. Twenty-five patients (25 of 50, 50%) were male. Twenty patients (20 of 50, 40%) used beta-blockers before RFCA. All patients had no structural heart disease except 1 patient with valvular aortic stenosis and coarctation of the aorta. RFCA was performed using the anatomic approach under fluoroscopic guidance. The most common successfully ablated region was the midseptal region (25 of 50, 50%). Slow pathway (SP) ablation and SP modulation were performed in 43 and 6 patients, respectively. Complication occurred in 1 patient with complete atrioventricular block. During follow-up, 6 patients had recurrence of supraventricular tachycardia, as confirmed by electrocardiography. Among them, 5 underwent successful ablation at the first procedure. In 1 patient, induction failed during the first procedure. Conclusion: RFCA is safe and effective in pediatric AVNRT patients. However, further research is needed for establishing the endpoints of ablation in pediatric AVNRT patients and for identifying risk factors by evaluating data on AVNRT recurrence after RFCA.

A Study on Doping Test of Bojungchisheup-tang (보중치습탕(補中治濕湯)의 도핑검사 대상약물(對象藥物)에 관(關)한 연구(硏究))

  • Kim, Sung-Yong;Geum, Dong-Ho;Lee, Myeong-Jong
    • Korean Journal of Oriental Medicine
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    • v.3 no.1
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    • pp.289-319
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    • 1997
  • Non-medical use of drugs to enhance performance at Olympic Games by athletes has been prohibited by the International Olympic Committee(IOC) since 1968 on medical and ethical grounds. IOC wants to protect athlete from harmful side effect of drugs due to misuse of it. It also, ethically, wants to have Games run on fair base, not fortified by performance enhancing drugs, The banned substances include stimulants, narcotic analgesics, anabolic sterolds, ${\beta}-blockers$ and diuretics. In order to prevent the positive reaction in the doping test induced by herb medicine, this study was done on about Bojungchisheup-tang. The laboratory set up doping analyses methods to cover as many drugs as possible without sacrificing sensitivity and specificity within one procedure. Its screening method consisted of four different procedures. The results were negative. According to the above results, Bojungchisheup-tang taken by athletes would show the negative reaction in the doping test. So its prescription for athletes can be given without worries of the doping test.

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Studies on the Physiological Properties of the Histamine Receptor of Ileal Smooth Muscle in Dog (개 회장 평활근에 있어서 Histamine Receptor의 생리적 특성에 관한 연구)

  • Kim, Joo-heon;Park, Yong-bae;Kwun, Jong-kuk
    • Korean Journal of Veterinary Research
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    • v.24 no.1
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    • pp.17-23
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    • 1984
  • To validate the physiological properties of the histamine receptors of ileal smooth muscle in dog, the effects of adrenergic-, cholineric-, and H-receptor antagonists on the responses of ileal smooth muscle strips to histamine were investigated. The results were summarized as follows; 1. Histamine caused the contraction of ileal smooth muscle and the contractile responses were increased between the concentration of histamine $10^{-7}M$ and $10^{-5}M$ with dose-dependent manner in dog. 2. The shorter the treatment interval of histamine, the lower the contractile activity until the treatment interval extended to 40 minutes. 3. The contractile response induced by histamine was completely blocked by the pre treatment with a $H_1$-receptor blocker, chlorpheniramine and not by the pretreatment with a $H_2$-receptor blockers cimetidine. 4. The contractile response induced by histamine was not blocked by the pretreatment with a cholinergic receptor blocker, atropine. 5. The contractile response induced by histamine was not blocked by the pretreatment with an ${\alpha}$-adrenergic receptor blocker, phenoxybenzamine, or a ${\beta}$-adrenergic receptor blocker, propranolol. From these results, it was suggested that the contraction induced by histamine was elicited through $H_1$-receptor on the ileal smooth muscle in dog.

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A Neonate Diagnosed with Wolff-Parkinson-White Syndrome Presenting with Cardiogenic Shock

  • Ha, Ji Eun;Lee, Sun Hyang;Park, Ga Young;Shin, Young-Lim;Kim, Sung Shin;Jang, Mi-Ae
    • Neonatal Medicine
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    • v.28 no.2
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    • pp.77-82
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    • 2021
  • We present the case of a healthy 28-day-old female full-term neonate who was admitted to the neonatal intensive care unit for severe metabolic acidosis, hypoglycemia, and an initial sinus rhythm. The first diagnostic hypothesis was hypovolemic shock, and fluid resuscitation was started immediately. During fluid therapy, cardiovascular collapse occurred with supraventricular tachycardia. The latter was successfully treated with adenosine and beta-blockers. After 8 days, electrocardiography showed ventricular pre-excitation, and Wolff-Parkinson-White syndrome was diagnosed. A novel variant of the MYL2 gene that is related to hypertrophic cardiomyopathy and conduction defect was found after discharge. Cardiogenic shock should be considered, despite being a rare cause of shock in neonates.

Excitatory Influences of Noradrenaline on the Spontaneous Contractions and Electrical Activity of Antral Circular Muscle of the Guinea-pig Stomach

  • Lee, Taik-Jong;Kim, Jin-Hwan;Kim, Ki-Whan
    • The Korean Journal of Physiology
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    • v.25 no.2
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    • pp.147-158
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    • 1991
  • The effects of noradrenaline on the spontaneous contraction recorded from a strip of mucosa-free antral circular muscle were studied in the guinea-pig stomach, and the changes in slow waves and membrane resistance were analyzed in order to elucidate the mechanism for the excitatory response to noradrenaline. Electrical responses of circular muscle cells were recorded using glass microelectrodes filled with 3 M KCI. Electrotonic potentials were produced to estimate membrane resistance by the partition stimulating method. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C$. The results obtained were as follows: 1) The spontaneous contractions were potentiated dose-dependently by the application of noradrenaline. 2) Through the experiments using adrenoceptor-blockers, the strong excitatory effect via $[\alpha}-adrenoceptors$ and the weak inhibitory efffect via ${\beta}-adrenoceptors$ were noted. 3) Noradrenaline produced hyperpolarization of membrane potential, and increases in the amplitude and the maximum rate of rise of slow waves. 4) In the presence of apamin, Ca-dependent K channel blocker, the characteristic hyperpolarization was not developed. However, the excitatory effect of noradrenaline on spontaneous contraction remained. 5) Membrane resistance was reduced during the hyperpolarized state by the application of noradrenaline, and the change of membrane resistance and the hyperpolarized state were completely abolished by apamin. From the above results, following conclusions could be made: Excitatory responses to noradrenaline result from the dominant ${\alpha}-excitatory$, and the weak ${\beta}-inhibitory$ action of noradrenaline. Hyperpolarization of membrane potential by noradrenaline is due to the activation of Ca-dependent K channel.

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Effect of Intravenous Intraoperative Esmolol on Pain Management Following Lower Limb Orthopedic Surgery

  • Haghighi, Mohammad;Sedighinejad, Abbas;Mirbolook, Ahmadreza;Nabi, Bahram Naderi;Farahmand, Maral;leili, Ehsan Kazemnezhad;Shirvani, Masoumeh;Jahromi, Sina Khajeh
    • The Korean Journal of Pain
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    • v.28 no.3
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    • pp.198-202
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    • 2015
  • Background: Lack of proper control of acute postoperative pain often leads to lingering or chronic pain. Several studies have emphasized the role of beta-blockers in reducing postoperative pain. Esmolol is a selective short-acting beta-blocker that produces few side effects. The purpose of this study was to examine the effect of intravenous intraoperative esmolol on postoperative pain reduction following orthopedic leg fracture surgery. Methods: In a clinical trial, 82 patients between 20-65 years of age with tibia fractures and American Society of Anesthesiologists (ASA) physical status I & II who underwent surgery were divided into two groups. Group A received esmolol and group B received normal saline. Postoperative pain was measured at three time points: entering the recovery unit, and at 3 h and 6 h following surgery, using the Visual Analogue Scale (VAS). A P value of < 0.05 was considered significant. Results: Mean VAS scores at all three time points were significantly different between the two test groups (P = 0.02, P = 0.0001, and P = 0.0001, respectively). The consumption of pethidine was lower in group A than in group B (P = 0.004) and the duration of its effect was significantly longer in time (P = 0.026). Conclusions: Intravenous intraoperative esmolol is effective in the reduction of postoperative pain following leg fracture surgery. It reduced opioid consumption following surgery and delayed patient requests for analgesics.

Study on Metabolism and Excretion of Carteolol in Human Urine using GC/MS (GC/MS를 이용한 carteolol의 대사 및 배설연구)

  • Min, Hye-Ki;Kim, Myungsoo;Cho, Hyun-Woo;Kim, Taek-Jae;Kim, Dong-Hyun;Myung, Seung-Woon
    • Analytical Science and Technology
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    • v.15 no.5
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    • pp.482-487
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    • 2002
  • International Olympic Committee (IOC) prohibits the use of carteolol which is one of ${\beta}$-blockers. To prove whether carteolol product was taken or not, the analytical method in urine using GC/MS was established, and metabolism and excretion study were evaluated. As compared with acid hydrolysis, enzyme hydrolysis method was more efficiency. Coefficients of variation for intra-assay precision was around 10%. Error was less than 5% except the concentration of $0.05{\mu}g/m{\ell}$. Recovery was 78.5% at $2{\mu}g/m{\ell}$. Free carteolol, conjugated carteolol, and small amount of p-OH carteolol were found in dosed human urine samples. The conjugated form was being 59.4% of the total carteolol in human urine. The amount of carteolol renal excreted for 72 h after oral dose of 10 mg of carteolol was 49% of the administred dose.

Korean Society of Heart Failure Guidelines for the Management of Heart Failure: Management of the Underlying Etiologies and Comorbidities of Heart Failure

  • Sang Min Park;Soo Youn Lee;Mi-Hyang Jung;Jong-Chan Youn;Darae Kim;Jae Yeong Cho;Dong-Hyuk Cho;Junho Hyun;Hyun-Jai Cho;Seong-Mi Park;Jin-Oh Choi;Wook-Jin Chung;Seok-Min Kang;Byung-Su Yoo;Committee of Clinical Practice Guidelines, Korean Society of Heart Failure
    • Korean Circulation Journal
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    • v.53 no.7
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    • pp.425-451
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    • 2023
  • Most patients with heart failure (HF) have multiple comorbidities, which impact their quality of life, aggravate HF, and increase mortality. Cardiovascular comorbidities include systemic and pulmonary hypertension, ischemic and valvular heart diseases, and atrial fibrillation. Non-cardiovascular comorbidities include diabetes mellitus (DM), chronic kidney and pulmonary diseases, iron deficiency and anemia, and sleep apnea. In patients with HF with hypertension and left ventricular hypertrophy, renin-angiotensin system inhibitors combined with calcium channel blockers and/or diuretics is an effective treatment regimen. Measurement of pulmonary vascular resistance via right heart catheterization is recommended for patients with HF considered suitable for implantation of mechanical circulatory support devices or as heart transplantation candidates. Coronary angiography remains the gold standard for the diagnosis and reperfusion in patients with HF and angina pectoris refractory to antianginal medications. In patients with HF and atrial fibrillation, longterm anticoagulants are recommended according to the CHA2DS2-VASc scores. Valvular heart diseases should be treated medically and/or surgically. In patients with HF and DM, metformin is relatively safer; thiazolidinediones cause fluid retention and should be avoided in patients with HF and dyspnea. In renal insufficiency, both volume status and cardiac performance are important for therapy guidance. In patients with HF and pulmonary disease, beta-blockers are underused, which may be related to increased mortality. In patients with HF and anemia, iron supplementation can help improve symptoms. In obstructive sleep apnea, continuous positive airway pressure therapy helps avoid severe nocturnal hypoxia. Appropriate management of comorbidities is important for improving clinical outcomes in patients with HF.