• The Korean Journal of Pharmacology
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• v.12 no.2 s.20
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• pp.33-41
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• 1976

Agkistrodon halys (Crotalidae) is the only species of poisonous snakes in Korea, and is divided into three subspecies; Agkistrodon bromhoffii brevicaudus, Agkistrodon calaginosus and Agkistrodon saxatilis. With the three venoms, the pharmacological actions on the cardiovascular system and intestine as well as some toxicological characteristics were studied. In addition, the precipitin test in an agar gel medium was employed for immunological comparison of the venoms and the sera of envenomed patients. The results obtained were as follows: Lyophilized venoms contained solids of $211{\sim}273mg/ml$, and LD50 to mice were 1.73 and 0.86 mg/kg in venoms of Agkistrodon bromhoffii brevicaudus obtained on July and October respectively, and 0.40 and 0.32 mg/kg in Agkistrodon calaginosus and the venoms of Agkistrodon saxatilis obtained on October was 2.29 mg/kg. Isoelectric focusing of lyophilized snake venoms showed 19 to 22 protein fractions and 2 to 3 isoamylase fractions. Acute irreversible hypotension was caused by the intravenous injection of large doses of venoms in rabbits and cats, but at the small doses, acute hypotension followed by slow recovery. Little changes of cardiac movements by the venom injection despite of marked hypotension were showed except bradycardia and arrhythmia prior the death. Also no changes on the isolated rabbit atria by the snake venoms were noted. The hypotensive effect of the snake venoms was prevented by the bilateral vagotomy or atropine pretreatment (1 mg/kg), but they did not affect when already the hypotension has undergone. In the isolated rabbit duodenum, small doses of venom increased the phasic movement, while large doses decreased after spastic contraction. With the injection of venoms in dog, strong contraction of gall-bladder was caused and it was not blocked by the pretreatment with phenoxybenzamine (10 mg/kg) or atropine (1.4 mg/kg). In the venoms of Agkistrodon bromhoffii brevicaudus and Agkistrodon calaginosus, at least 5 antigenic components were detected, and four of them were shared in common with each other. Polyvalent antivenin (Wyeth Lab. USA) had three common precipitating antibodies with the venom of Agkistrodon bromhoffii brevicaudus and Akistrodon calaginosus. In the serum of envenomed patients, no precipitating antibodies were seen to the venoms and little changes in serum protein, GOT and GPT were observed. In conclusion, the snake venoms obtained in Korea were highly toxic and caused chiefly the vascular collapse leading to death. This vascular collapse was resulted largely by cholinergic effects, and not cardiotoxin of venoms. In human, it is likely that precipitating antibodies to venom were not produced by an envenomed incidence to poisonous snakes.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.6
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• pp.629-639
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• 2016

The present study was designed to investigate the characteristics of gintonin, one of components isolated from Korean Ginseng on secretion of catecholamines (CA) from the isolated perfused model of rat adrenal gland and to clarify its mechanism of action. Gintonin (1 to $30{\mu}g/ml$), perfused into an adrenal vein, markedly increased the CA secretion from the perfused rat adrenal medulla in a dose-dependent fashion. The gintonin-evoked CA secretion was greatly inhibited in the presence of chlorisondamine ($1{\mu}M$, an autonomic ganglionic bloker), pirenzepine ($2{\mu}M$, a muscarinic $M_1$ receptor antagonist), Ki14625 ($10{\mu}M$, an $LPA_{1/3}$ receptor antagonist), amiloride (1 mM, an inhibitor of $Na^+/Ca^{2+}$ exchanger), a nicardipine ($1{\mu}M$, a voltage-dependent $Ca^{2+}$ channel blocker), TMB-8 ($1{\mu}M$, an intracellular $Ca^{2+}$ antagonist), and perfusion of $Ca^{2+}$-free Krebs solution with 5mM EGTA (a $Ca^{2+}$chelater), while was not affected by sodium nitroprusside ($100{\mu}M$, a nitrosovasodialtor). Interestingly, LPA ($0.3{\sim}3{\mu}M$, an LPA receptor agonist) also dose-dependently enhanced the CA secretion from the adrenal medulla, but this facilitatory effect of LPA was greatly inhibited in the presence of Ki 14625 ($10{\mu}M$). Moreover, acetylcholine (AC)-evoked CA secretion was greatly potentiated during the perfusion of gintonin ($3{\mu}g/ml$). Taken together, these results demonstrate the first evidence that gintonin increases the CA secretion from the perfused rat adrenal medulla in a dose-dependent fashion. This facilitatory effect of gintonin seems to be associated with activation of LPA- and cholinergic-receptors, which are relevant to the cytoplasmic $Ca^{2+}$ increase by stimulation of the $Ca^{2+}$ influx as well as by the inhibition of $Ca^{2+}$ uptake into the cytoplasmic $Ca^{2+}$ stores, without the increased nitric oxide (NO). Based on these results, it is thought that gintonin, one of ginseng components, can elevate the CA secretion from adrenal medulla by regulating the $Ca^{2+}$ mobilization for exocytosis, suggesting facilitation of cardiovascular system. Also, these findings show that gintonin might be at least one of ginseng-induced hypertensive components.

• Journal of Yeungnam Medical Science
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• v.6 no.2
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• pp.207-215
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• 1989

The authors studied ED50 of bethanechol on the contractilities of the smooth muscles isolated from various organs of rat under the presence of atropine(a classical competitive blocker of cholinergic muscarinic receptor) or minaprine(a newly developed antidepressant drug) to investigate the pheripheral anticholinergic effect of minaprine. The results were as follows ; 1) There was no significant difference between ED50 of bethanechol in the control group and that under the presence of minaprine $10^{-8}M$ and $10^{-7}M$ in the smooth muscles isolated from the duodenum. 2) There was no significant difference between ED50 of bethanechol in the control group and that under the presence of minaprine $10^{-8}M$ and $10^{-7}M$ in the smooth muscles isolated from the ascending colon. 3) There was significant difference between ED50 of bethanechol in the control group and that under the presence of minaprine $10^{-8}M$ and $10^{-7}M$ in the smooth muscles isolated from the urinary bladder(P<0.01). 4) There was significant difference between ED50 of the atropine $10^{-8}M$ and minaprine ($10^{-8}M$) in the smooth muscles isolated from the urinary bladder(P<0.05).

• The Korean Journal of Pharmacology
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• v.24 no.1
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• pp.31-42
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• 1988

The effect of Panaxadiol(PD), which is an active component of Korean Ginseng Saponins, on the secretion of catecholamines (CA) from the rabbit adrenal gland and its mode of action were investigated in the present study. $PD(400{\mu}g)$ increased significantly the secretion of CA from the isolated perfused rabbit adrenal gland. PD-induced secretion of CA was reduced markedly by treatment of atropine, CA secretion induced by Ach or PD was potentiated significantly by physostigmine-treatment. Chlorisondamine did inhibit CA secretion of PD or Ach. Perfusion of $PD(400{\mu}g)$ for 30 min enhanced the secretory activity of CA by Ach. Ouabain weakened the secretory response induced by PD but rather enhanced the response by Ach. Adenosine-treatment resulted in marked enhancement of CA secretion by PD or Ach, Pefusion with $Ca^{2+}-free$ Krebs containing EGTA (5 mM) for about 30 min totally blocked secretory effect induced by Ach and also weakened that by PD. From the above experimental results, it is suggested that PD causes secretion of catecholamines from the rabbit adrenal gland by a calcium-dependent exocytotic mechanism. The secretory effect of PD is due to the stimulation of cholinergic muscarinic and nicotinic receptors present in the adrenal gland and partly to a direct action on the chromaffin cell itself.

• The Korean Journal of Pharmacology
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• v.28 no.2
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• pp.181-190
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• 1992

The present study was conducted to investigate the effect of opioids on catecholamine (CA) secretion evoked by a selective cholinergic nicotinic agonist, 1,1-dimethyl-4-phenyl piperazinium (DMPP) and acetylcholine from the retrogradely perfused rat adrenal glands. Methionine-enkephalin $(9.68{\times}10^{-6}\;M)$ caused a significant inhibition of CA secretion evoked by DMPP (100 uM) and $ACh\;(50\;{\mu}g)$, but had no effect on the spontaneous (basal) CA release. Morphine $(1.73{\times}10^{-5}\;M)$ attenuated considerablely the increase in CA release induced by DMPP and ACh. Morphine itself also did not affect the basal CA output. A 20 to 65% reduction of the DMPP- and ACh-evoked increase in CA release was observed after the pretreatment with methionine-enkephalin or morphine. The increase in CA release evoked by DMPP and ACh was reduced markedly by preloading with an opiate antagonist naloxone $(1.22{\times}10^{-7}\;M)$ while basal CA output was not affected by naloxone. These present experimental results suggest that the nicotinic stimulation-evoked CA release from the perfused rat adrenal gland is inhibited by endogenously released opioid peptides through activation of opiate receptors located in the adrenal gland.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.4
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• pp.215-223
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• 2002

The present study was undertaken to investigate the effect of doxorubicin (DX) on secretion of catecholamines (CA) evoked by ACh, high $K^+,$ DMPP and McN-A-343 from the isolated perfused rat adrenal gland and to establish the mechanism of its action. DX $(10^{-7}{\sim}10^{-6}\;M)$ perfused into an adrenal vein for 60 min produced relatively dose- and time-dependent inhibition of CA secretory responses evoked by ACh $(5.32{\times}10^{-3}\;M),$ DMPP $(10^{-4}\;M)$ and McN-A-343 $(10^{-4}\;M).$ However, lower dose of DX did not affect CA secretion by high $K^+\;(5.6{\times}10^{-2}\;M),$ but its higher doses depressed time-dependently CA secretion evoked by high $K^+.$ DX itself did also fail to affect basal CA output. In adrenal glands loaded with DX $(3{\times}10^{-7}\;M),$ CA secretory responses evoked by Bay-K-8644, an activator of L-type $Ca^{2+}$ channels and cyclopiazonic acid, an inhibitor of cytoplasmic $Ca^{2+}-ATPase$ were time-dependently inhibited. Furthermore, daunorubicin $(3{\times}10^{-7}\;M),$ given into the adrenal gland for 60 min, attenuated CA secretory responses evoked by ACh, high $K^+,$ DMPP and McN-A-343. Taken together, these results suggest that DX causes relatively dose- and time-dependent inhibition of CA secretory responses evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors from the isolated perfused rat adrenal gland. However, lower dose of DX did not affect CA secretion by high $K^+,$ and higher doses of DX reduced time-dependently CA secretion of high $K^+.$ It is thought that these effects of DX may be mediated by inhibiting both influx of extracellular calcium into the rat adrenomedullary chromaffin cells and intracelluar calcium release from the cytoplasmic store. Also, there was no difference in the mode of action between DX and daunorubicin in rat adrenomedullary CA secretion.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.1
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• pp.99-109
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• 2013

The aim of this study was to determine whether fimasartan, a newly developed $AT_1$ receptor blocker, can affect the CA release in the isolated perfused model of the adrenal medulla of spontaneously hypertensive rats (SHRs). Fimasartan (5~50 ${\mu}M$) perfused into an adrenal vein for 90 min produced dose- and time-dependently inhibited the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (56 mM, a direct membrane depolarizer), DMPP (100 ${\mu}M$) and McN-A-343 (100 ${\mu}M$). Fimasartan failed to affect basal CA output. Furthermore, in adrenal glands loaded with fimasartan (15 ${\mu}M$), the CA secretory responses evoked by Bay-K-8644 (10 ${\mu}M$, an activator of L-type $Ca^{2+}$ channels), cyclopiazonic acid (10 ${\mu}M$, an inhibitor of cytoplasmic $Ca^{2+}$-ATPase), and veratridine (100 ${\mu}M$, an activator of $Na^+$ channels) as well as by angiotensin II (Ang II, 100 nM), were markedly inhibited. In simultaneous presence of fimasartan (15 ${\mu}M$) and L-NAME (30 ${\mu}M$, an inhibitor of NO synthase), the CA secretory responses evoked by ACh, high $K^+$, DMPP, Ang II, Bay-K-8644, and veratridine was not affected in comparison of data obtained from treatment with fimasartan (15 ${\mu}M$) alone. Also there was no difference in NO release between before and after treatment with fimasartan (15 ${\mu}M$). Collectively, these experimental results suggest that fimasartan inhibits the CA secretion evoked by Ang II, and cholinergic stimulation (both nicotininc and muscarinic receptors) as well as by membrane depolarization from the rat adrenal medulla. It seems that this inhibitory effect of fimasartan may be mediated by blocking the influx of both $Na^+$ and $Ca^{2+}$ through their ion channels into the rat adrenomedullary chromaffin cells as well as by inhibiting the $Ca^{2+}$ release from the cytoplasmic calcium store, which is relevant to $AT_1$ receptor blockade without NO release.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.295-301
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• 2017

Botulinum neurotoxin (BoNT/A) is a neurotoxin that selectively attacks the peripheral cholinergic nerve endings. It is produced by Gram -positive, endospore-forming strict anaerobic bacteria, Clostridium botulinum. Since BoNT/A could be a biothreat agent, as well as a contaminator of food and water supplies, the development of sensitive assays for toxin detection and potent antitoxin for the treatment of intoxication is necessary. In this study, for the purpose of producing monoclonal antibodies (mAbs) that are capable of neutralizing Botulinum neurotoxin type A (BoNT/A), scFv (single-chain variable domain fragment) libraries from the rabbit antisera against BoNT/A was fused to a human IgG. The resulting recombinant scFvIgG antibody protein was expressed in stable cell lines and was purified using a protein A affinity chromatography. The efficacy of scFvIgG mAb was confirmed by ELISA and was evaluated for the neutralization of BoNT/A in vivo. Such an in vivo toxin neutralization assay was performed using mice. Although scFvIgG antibody proteins (10 ug) failed to fully protect the mice challenged with BoNT/A (100,000 $LD_{50}$), it significantly prolonged the survival time. These results suggest that scFvIgG mAb may be capable of neutralizing BoNT/A single-chain variable domain fragment.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.1
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• pp.45-53
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• 2005

The present study was designed to examine the effect of d-amphetamine on CA release from the isolated perfused model of the rat adrenal gland, and to establish its mechanism of action. Damphetamine $(10{\sim}100{\mu}M$), when perfused into an adrenal vein of the rat adrenal gland for 60 min, enhanced the CA secretory responses evoked by ACh ($5.32{\times}10^{-3}$ M), excess $K^+$ ($5.6{\times}10^{-2}$ M, a membrane depolarizer), DMPP ($10^{-4}$ M, a selective neuronal nicotinic $N_n-receptor$ agonist) and McN-A-343 ($10^{-4}$ M, a selective $M_1-muscarinic$ agonist) only for the first period (4 min), although it alone has weak effect on CA secretion. Moreover, d-amphetamine ($30{\mu}M$) in to an adrenal vein for 60 min also augmented the CA release evoked by BAY-K-8644, an activator of the dihydropyridine L-type $Ca^{2+}$ channels, and cyclopiazonic acid, an inhibitor of cytoplasmic $Ca^{2+}$ ATPase only for the first period (4 min). However, in the presence of high concentration ($500{\mu}M$), d-amphetamine rather inhibited the CA secretory responses evoked by the above all of secretagogues. Collectively, these experimental results suggest that d-amphetamine at low concentrations enhances the CA secretion from the rat adrenal medulla evoked by cholinergic stimulation (both nicotininc and muscarinic receptors) as well as by membrane depolarization, but at high concentration it rather inhibits them. It seems that d-amphetamine has dual effects as both agonist and antagonist at nicotinic receptors of the isolated perfused rat adrenal medulla, which might be dependent on the concentration. It is also thought that these actions of d-amphetamine are probably relevant to the $Ca^{2+}$ mobilization through the dihydropyridine L-type $Ca^{2+}$ cha$N_n$els located on the rat adrenomedullary chromaffin cell membrane and the release of $Ca^{2+}$ from the cytoplasmic store.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.2
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• pp.192-196
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• 2012

In the present study, we examined the effect of the aqueous extract of Rubus coreanus Miquel (RCM-Ex) on scopolamine-induced memory impairment in male ICR mice. Mice were fed the diet containing 100 mg/kg body weight/day of RCM-Ex for 4 weeks. To induce amnesia, scopolamine (an antagonist of muscarinic acetylcholine receptor, 1 mg/kg of body weight) was intraperitoneally injected into mice 30 min before starting the behavior tests. RCM-Ex reversed scopolamine-induced memory impairments in mice as evidence by the passive avoidance test and Morris water maze test. In addition, acetylcholineasterase activities were decreased in the brains of mice treated with RCM-Ex. These results suggest that RCM-Ex may be an effective agent for the prevention of the memory impairment induced by cholinergic dysfunction.