• Title/Summary/Keyword: cholinergic

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Cholinergic Role on Insulin Action in Exocrine Secretion of the Isolated Rat Pancreas

  • Lee, Yun-Lyul;Park, Hyung-Seo;Kim, Myoung-Sub;Kwon, Hyeok-Yil;Park, Hyoung-Jin
    • The Korean Journal of Physiology
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    • v.30 no.2
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    • pp.219-229
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    • 1996
  • In order to investigate intra-pancreatic cholinergic roles on insulin action in exocrine secretion, the pancreas was isolated from rats and continuously perfused with modified Krebs-Henseleit solution. Intra-arterial infusion of insulin (100 nM) or cholecystokinin (CCK, 14 pM) alone resulted in stimulation of the volume flow and amylase output. Also insulin potentiated the action of CCK in the exocrine secretion. Tetrodotoxin and atropine completely abolished the potentiating action of insulin and CCK as well as the action of insulin alone, but did not change the action of CCK alone. In order to see an effect of intra-pancreatic neural activation on the insulin action, electrical field stimulation (EFS) with parameters of 20 V, 2 msec and 8 Hz was applied to the isolated pancreas for 10 min under 2.5 or 18 mM glucose background. The EFS voltage-dependently elevated the flow rate and amylase output, and potentiated exocrine secretion in 18 mM glucose infusion compared with 2.5 mM glucose. The potentiating effects of EFS and 18 mM glucose were not observed in the streptozotocin-treated pancreas although it was perfused with 18 mM glucose. However, it was restored when the diabetic pancreas was perfused with porcine insulin(100 nM). Tetrodotoxin and atropine inhibited the pancreatic secretion induced by EFS with the background of 18 mM glucose. The results of present investigation indicate that the intra-pancreatic cholinergic tone exerts a stimulatory influence on the action of insulin in pancreatic exocrine secretion of rats.

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The Pharmacology of Botulinum Toxin (보툴리눔 독소의 약리)

  • Lee, Sang Hyuk;Lee, Hyun Sub;Jin, Sung Min
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.23 no.2
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    • pp.93-98
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    • 2012
  • Botulinum toxins are the most potent toxins known to mankind. Botulinum toxin acts by blocking the cholinergic neuromuscular or the cholinergic autonomic innervation of exocrine glands and smooth muscles. Seven distinct antigenic botulinum toxins (A, B, C, D, E, F and G) produced by different strains of Clostridium botulinum have been described and only A and B type of botulinum toxins were clinically used. Toxins were consisted of a heavy chain with a molecular weight of 100 kD and a light chain with a molecular weight of 50 kD. Toxins are bound with an astounding selectivity to glycoprotein structures located on the cholinergic nerve terminal. Subsequently light chain of toxin is internalized and cleaves different proteins of the acetylcholine transport protein cascade transporting the acetylcholine vesicle from the intracellular space into the synaptic cleft. After a decade of therapeutic application of the toxin, no anaphylaxis or deaths have been reported and systemic adverse effects have not been reported so far. However the toxin's immunologic properties can lead to the stimulation of antibody production, potentially rendering further treatments ineffective. Botulinum toxin is a safe and effective treatment. Use of botulinum toxin in clinical medicine has grown exponentially in recent years, and many parts of the human body are now being targeted for therapeutic purposes.

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Study of Effects of Electroacupuncture on the Hippocampal Cholinergic Neuronal Activity

  • Lee Kwang Ro;Kang Sei Young;Yoon Ji Won;Cho Chang Hyun;Sung Kang Keyng
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.6
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    • pp.1850-1855
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    • 2004
  • The purpose of this report is to investigate the electroacupuncture effect on the cholinergic neuronal activation in the hippocampal CA1 section. The electroacupuncture was performed on S36 of white rats and its consequencies were investigated by immunohistochemical method. Hippocampal CA1 sections of Sprague Dawley white male rats electroacupunctured on S36 at 20㎐ and 100㎐ are stained by cresyl violet to show that the values of 100㎐ and 20㎐ group increased significantly compared to sham group's one. Especially, 100㎐ group shows stronger neuronal activation compared to 20㎐ group. Induction of AChE, a neurotransmitter, in hippocampal CA1 is increased significantly in 100㎐ and 20㎐ group compared to sham group. Especially 20㎐ group shows higher AChE immunoreaction than 100㎐ does, although it wasn't significant enough. Induction of NGF(Nerve Growth Factor) in hippocampal CA1 sections was observed higher in 20㎐ and 100㎐ group than in sham group. Especially, 20㎐ group shows higher NGF immunoreaction compared to 100㎐. The facts above indicate that the eletroacupucture is effect to the cholinergic neuronal activation of hippocampus induced by focal ischemia.

Phellodendron amurense and Its Major Alkaloid Compound, Berberine Ameliorates Scopolamine-Induced Neuronal Impairment and Memory Dysfunction in Rats

  • Lee, Bom-Bi;Sur, Bong-Jun;Shim, In-Sop;Lee, Hye-Jung;Hahm, Dae-Hyun
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.2
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    • pp.79-89
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    • 2012
  • We examine whether Phellodendron amurense (PA) and its major alkaloid compound, berberine (BER), improved memory defects caused by administering scopolamine in rats. Effects of PA and BER on the acetylcholinergic system and pro-inflammatory cytokines in the hippocampus were also investigated. Male rats were administered daily doses for 14 days of PA (100 and 200 mg/kg, i.p.) and BER (20 mg/kg, i.p.) 30 min before scopolamine injection (2 mg/kg, i.p.). Daily administration of PA and BER improved memory impairment as measured by the passive avoidance test and reduced the escape latency for finding the platform in the Morris water maze test. Administration of PA and BER significantly alleviated memory-associated decreases in cholinergic immunoreactivity and restored brain-derived neurotrophic factor and cAMP-response element-binding protein mRNA expression in the hippocampus. PA and BER also decreased significantly the expression of proinflammatory cytokines such as interleukin-$1{\beta}$, tumor necrosis factor-${\alpha}$ and cyclooxygenase-2 mRNA in the hippocampus. These results demonstrated that PA and BER had significant neuroprotective effects against neuronal impairment and memory dysfunction caused by scopolamine in rats. These results suggest that PA and BER may be useful as therapeutic agents for improving cognitive functioning by stimulating cholinergic enzyme activity and alleviating inflammatory responses.

The Role of Nitric Oxide in Non-adrenergic Non-cholinergic Relaxation in the Rabbit Penile Corpus Cavernosum (토끼 음경해면체의 비-아드레날린 비-콜린성 이완반응에서 산화질소의 역할)

  • Park, Mi-Sun;Kim, Jin-Bo;Hong, Eun-Ju;Hong, Sung-Cheul
    • YAKHAK HOEJI
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    • v.41 no.3
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    • pp.370-380
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    • 1997
  • The role of nitric oxide (NO) on the non-adrenergic non-cholinergic (NANC) relaxations induced by the short and prolonged electrical field stimulation (EFS) has been studied in the rabbit corpus cavernosum. In the presence of atropine and guanethidine the prolonged EFS (2-16 Hz) of corpus cavernosal strips precontracted with phenylephrine produced frequency-dependent relaxations, which were abolished by tetrodotoxin as shown in the relaxations induced gy the short EFS, indicating that their orgin is NANC nerve stimulation. $N^G$-nitro-L-arginine (L-NNA), inhibitor of nitirc oxide synthase, caused a concentration-dependent inhibition to the NANC relaxation, and at 100 M L-NNA the relaxation were virtually abolished. The inhibitory effect of L-NNA was reversed by L-arginine. Hemoglobin abolished the relaxations to NO and also caused a concentration-dependent inhibition of the NANC relaxation. The hemoglobin-resistant relaxation induced by EFS was eliminated by L-NNA. Methylene blue significantly reduced the NANC relaxation in a conentration-dependent manner. The NANC relaxation was not affected by a VIP-inactivating pepridase, alpha0chymotrypsin, whereas VIP-induced relaxation was completely abolished. NO- and VIP-induced relaxation were not affected by L-NNA. These results indicate that the NANC relaxation induced by prolonged EFS of the rabbit corpus cavernosum is mediated by NO-guanosine 3',5'-cyclic monophosphate pathway as shown in the relaxation induced by the short EFS, and that VIP release is not essential for the NANC relaxation of the rabbit corpus cavernosum and VIP is not involved the generation fo NO.

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Loss of cholinergic innervations in rat hippocampus by intracerebral injection of C-terminal fragment of amyloid precursor protein

  • Han, Chang-Hoon;Lee, Young Jae
    • Korean Journal of Veterinary Research
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    • v.48 no.3
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    • pp.251-258
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    • 2008
  • The neurotoxicity of C-terminal fragments of amyloid precusor protein (CT) is known to play some roles in Alzheimer's disease progression. In this study, we investigated the effects of the recombinant C-terminal 105 amino acid fragment of amyloid precusor protein (CT105) on cholinergic function using CT105-injected rat. To study the effects of CT105 on septohippocampal pathway, choline acetyltransferase (ChAT) positive neurons were examined in the medial septum and in the diagonal band after an injection of CT105 peptide into the lateral ventricle. Immunohistological analysis revealed that the number of ChAT-immunopositive cells decreased significantly in both medial septum and diagonal band. In addition, CT105 decreased ChAT-immunopositive cells in the hippocampal area, particulary in the dentate gyros. To study the effect of amyloid beta peptide ($A{\beta}$) and CT105 on the cholinergic system, each peptide was injected into the left lateral ventricle, and acetylcholine (ACh) levels were monitored in hippocampus. ACh level in the hippocampal area was reduced to 60% of control level in $A{\beta}$-treated group, and the level was reduced to 15% of control level in CT105-treated group, at one week after the injection. ACh level was further reduced to 35% of control in $A{\beta}$-treated group, whereas the level was slightly increased to 30% of control in CT105-treated group at 4 weeks after the injection. Taken together, the results in the present study suggest that CT105 impairs the septohippocampal pathway by reducing acetylcholine synthesis and release, which results in damage of learning and memory.

Influence of Quinidine on Catecholamine Secretion Evoked by Cholinergic Stimulation and Membrane Depolarization from the Perfused Rat Adrenal Gland

  • Lim, Dong-Yoon;Jeon, Yong-Joon;Yang, Won-Ho;Lim, Geon-Han;Kim, Il-Hwan;Lee, Seung-Myeong;Hong, Soon-Pyo
    • Biomolecules & Therapeutics
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    • v.8 no.1
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    • pp.13-21
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    • 2000
  • The present study was designed to investigate the effect f quinidine on catecholamine (CA) secretion evoked by ACh, high $K^{+}$, DMPP, McN-A343, cyclopiazonic acid and Bay-K-8644 from the isolated perfused rat adrenal gland and to establish the mechanism of its action. The perfusion of quinidine (15-150 $\mu$M) into an adrenal vein for 60 min produced relatively dose- and time-dependent inhibition in CA secretion evoked by ACh (5.32$\times$10$^{-3}$ M), high $K^{+}$ (5.6$\times$10$^{-2}$ M), DMPP (10$^{-4}$ M for 2 min), McN-A-343 (10$^{-4}$ M for 2 min), cyclopiazonic acid (10$^{-5}$ M for 4 min) and Bay-K-8644 (10$^{-5}$ M for 4 min). Furthermore, in adrenal glands pre-loaded with quinine (5$\times$10$^{-5}$ M), CA secretory responses evoked by veratridine (10$^{-4}$ M) was time-dependently inhibited. Also, in the presence of lidocaine (10$^{-4}$ M), which is also known to be a sodium channel blocker, CA secretory responses evoked by ACh, high potassium, DMPP, McN-A-343, Bay-K-8644 and cyclo-piazonic acid were also greatly reduced in similar fashion to that of quinidine-treatment. Taken together, these results suggest that quinidine causes greatly the inhibition of CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as by membrane depolarization, indicating strongly that this effect may be mediated by inhibiting influx of extracellular calcium and release in intracellular calcium in the rat adrenomedullary chromaffin cells. Furthermore, these findings indicate strongly that this inhibitory action of quinidine appears to be associated to the blocking action of sodium channels at least in CA secretion from the rat adrenal gland.and.

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Cholinergic Contraction to the Perivascular Nerve Stimulation on the Isolated Coronary Artery of Pig (돼지 적출 심장 관상동맥에 있어서 Perivascular Nerve Stimulation에 의한 Cholinergic 수축 작용)

  • Lee, Han-Ki;Goo, Bong-Oh;Moon, Sang-Eun;Shim, Chul-Soo
    • The Journal of Korean Physical Therapy
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    • v.13 no.1
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    • pp.61-71
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    • 2001
  • The purpose oi this study is to identify clearly the physiologic significance of autonomic nervous system. This study is to find the loose of endogenous neurotransmitter while using the neural response of the neural excitatory action which is distributed to the perivascular smooth muscle through the electrical stimulation of the smooth muscle of coronary artery of pig. The effects of perivascular nerve stimulation were investigated on isolated coronary artery of pig.1 . The magnitude of contractile response to perivascular nerve stimulation increased with increasing frequency (2-80 Hz) of stimulation. 2. The contractions to perivascular nerve stimulation(40V, 40Hz. 0.5msec, 1 min) were increased greatly by pretreatment of the cholinestrase inhibitor physostigmine. 3. The contraction to perivascular nerve stimulation(40V,40Hz, 0.5msec, 1min) was antagonised markedly by the muscarinic antagonist atropine. 4. The contraction to perivascular nerve stimulation(40V, 40Hz, 0.5msec, 1 min) was blocked by the neural blocker tetrodotoxin. 5. The contractions to perivascular nerve stimulation(40V. 40Hz, 0.5msec, 1 min) were not affected significantly by the -adrenergic antagonist phentolamine or - adrenergic antagonist propranolol. 6. The contractile response by the acetylcholine was increased by the pretreatment of cholinestrase inhibitor physostigmine. The finding suggest that it is powerful excitatory action linked to muscarinic receptor by cholinergic nerve in coronary artery of pig.

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