• Korean Journal of Veterinary Service
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• v.17 no.2
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• pp.122-129
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• 1994

Teratogenic effects of diazinon were assessed morphologically and cholinergic blocking agents. Diazinon at doses ranging from 25 to 2000 ug /egg, was Injected on day 3 of incubation. TD50s were different for the various teratogenic signs (wry neck, micromelia, abnormal feathering, abnormal beak and curled claws). The threshould dose for wry neck was higher than threshould dose for other signs； 40 ug/egg produced substantial micromelia, abnormal feathering. abnormal beak and curled claws, but gave no signs of wry neck. In contrast to the teratogenic doses, the LD50 of diazinon was very high (above 2000 ug /egg). One of the characteristics of diazinon-induced teratogenesis was reduced body weight (78.7％) and body length (73.8%). Maximal teratogenic effects, scored as signs of retarded growth, wry neck micromelia, abnormal feathering, abnormal beak, and curled claws, were produced when the insectcide was administered on the third or fourth day. The threshold dose for type II teratogenic signs(such as wry neck and short neck) was higher than for type I (such as micromelia and abnormal feathering). Morphological studies, using atropine and gallamine, suggested that nicotine but not muscarinic receptors may be involved in the mechanism of diazinon induced type II malformations.

• Korean Journal of Veterinary Research
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• v.33 no.1
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• pp.71-80
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• 1993

The central nervous system depressant effect of xylazine and xylazine-ketamine was studied in chicken and mice. Intraperitoneal injection of xylazine(1~30 mg/kg) and xylazine(1~30 mg/kg)-ketamine(100 mg/kg) induced a loss of the righting reflex in chicken and mice, respectively. These effects of xylazine were dose-dependent. The results obtained were as follows; 1. The effect of xylazine-induced depression was antagonized by adrenergic antagonists having ${\alpha}_2$-blocking activity(yohimbine, tolazoline, piperoxan and phentolamine). 2. Yohimbine was most effective in the reduction of the CNS depression by xylazine. 3. Phenoxybenzamine and prazosin did not reduced CNS depression by xylazine in both species. 4. Labetalol (${\alpha}_1$, ${\beta}_1$-adrenergic antagonist) and propranolol(${\beta}$-adrenergic blocking agent) were not effective in reducing xylazine induced depression. 5. Cholinergic blocking agents (atropine and mecamylamine), a dopaminergic antagonist (Haloperidol), a histamine $H_1$-antagonist(chlorpheniramine), a histamine $H_2$-antagonist(cimetidine), a serotonergic-histamine $H_1$ antagonist(cyproheptadine) were not effective in reducing xylazine-induced depression. 6. Xylazine-induced depression is mediated by ${\alpha}_2$-adrenergic receptors and appears not to be involved in cholinergic, dopaminergic, serotonergic or histaminergic pathways.

• YAKHAK HOEJI
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• v.35 no.4
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• pp.341-347
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• 1991

It was reported that protein carboxymethylation is involved in amylase secretion of parotid gland by isoproterenot. It was also suggested that a small part of the total cellular protein carboxymethylation is directly involved in pancreatic enzyme secretion. On the contrary, other authors reported that there is no relationship between protein carboxymethylation and secretion in pancreas and parotid gland. In recent study, it was proposed that a methyl acceptor protein plays a limited modulatory role in the coupling of cytosolic $Ca^{++}$ accumulation and exocytosis. In this study, the effects of cholinergic and adrenergic agents on the activities of protein methylase II in pancreatic tissues were examined to test the relationship between protein methylation and pancreatic secretion. The results are as follows. The activity of amylase was slightly increased at the concentration of $10^{-5}$ M of isoproterenol and norepinephrine. The activities of protein methylase I and II were decreased by isoproterenol and norepinephrine, but the activities of protein methylase III were hardly changed. The cholinergic stimulants acetylcholine and carbachol at a concentration of $10^{-5}$ M increased the activities of protein methylase I and decreased the activitiy of protein methylase III compared with control.

• YAKHAK HOEJI
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• v.27 no.4
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• pp.295-301
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• 1983

Among the many protein modifications methylation is being investigated actively with regard to bacterial chemotaxis, gene regulation, muscle contraction, cytochrome c methylation, and the synthesis of the acyl transporter, carnitine. In this study the activities of protein methylase I, II, and III in pancreatic tissues of rat, mouse, and guinea pig were examined. Furthermore, the effect of cholinergic agents on the activity of protein methylases in pancreatic fragment of guinea pig was also examined in order to test the relationship between protein methylation and pancreatic secretion. The results are as follows. 1) The activities of protein methylases were generally high in pancreatic tissues of guinea pig and mouse but low in the tissue of rat. 2) The cholinergic stimulants, acetylcholine and carbachol at a concentration of $10^{-5}M$ decreased the activities of protein methylase I, II, and III compared with unstimulated control. 3) The inhibitory effect of the cholinergic stimulant on the activities of protein methylases was not blocked by atropine at a concentration of $10^{-5}M$.

• Korean Journal of Veterinary Research
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• v.34 no.1
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• pp.49-54
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• 1994

Teratogenic effects of diazinon were assessed on morphology of chick embryos cholinergic blocking agents. Diazinon at doses ranging from 25 to $2000{\mu}g/egg$, was injected on Day 3 of incubation. $TD_{50S}$, were different for the various teratogenic sings such as wry neck, micromelia, abnormal feathering, abnormal beak and curled claws. The threshold dose for wry neck was higher than the threshold dose for other signs; $40{\mu}g/egg$ produced substantial micromelia, abnormal feathering, abnormal beak and curled claws, but gave no sings of wry neck. In contrast to the teratogenic doses, the $LD_{50}$ of diazinon was very high(above $2000{\mu}g/egg$). One of the characteristics of diazinon-induced teratogenesis was reduction of body weight(78.8%) and body length(73.8%). Maximal teratogenic effects, scored as sings of retarded growth, wry neck, micromelia, abnormal feathering, abnormal beak, and curled claws, were produced when the insectcide was administered on the third or fourth day. The threshold dose for type II teratogenic sings including wry neck and short neck was higher than for type I including micromelia and abnormal feathering. Morphorlogical studies, using atropine and gallamine, suggested that nicotinc but not muscarinic receptors may be involved in the mechanism of diazinon-induced type II malformations.

• Korean Journal of Veterinary Research
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• v.35 no.2
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• pp.237-243
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• 1995

The effects of various autonomic blocking agents to 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(280Hz) of stimulation. 2. The contractions to perivascular nerve stimulation(40V, 40Hz, 0.5msec, 1min) were increased by pretreatment of the cholinestrase inhibitor, physostigmine. 3. The contraction to perivascular nerve stimulation(40V, 40Hz, 0.5msec, 1min) was antagonised by the muscarinic antagonist, atropine. 4. The contraction to perivascular nerve stimulation(40V, 40Hz, 0.5msec, 1min) was blocked by the neural blocker, tetrodotoxin. 5. The contractions to perivascular nerve stimulation(40V, 40Hz, 0.5msec, 1min) were not significantly affected by the ${\alpha}$-adrenergic antagonist, phentolamine or ${\beta}$-adrenergic antagonist, propranolol. 6. The contractile response by the acetylcholine was increased by the pretreatment of cholinestrase inhibitor, physostigmine. This findings suggest that the powerful excitatory action by the perivascular nerve stimulation may be linked to muscarinic receptor by cholinergic nerve excitation in coronary artery of pig.

• Journal of Chest Surgery
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• v.29 no.5
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• pp.487-494
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• 1996

The neurogenic responses of tracheal smooth muscles to electrical field stimulation (EFS) is biphasic, consisting firstly of cholinergic contraction followed by a slow and sustained relaxation. It is well known that a sustained relaxation involves the inhibitory non-adrenergic non-cholinergic systems. This study was done to Investigate the relaxing agents and their action mechanisms by use of an organ bath with plati- ilum . The tracheal smooth muscle relaxation due to EFS was suppressed by L-NAME, the WO (Nitric Oxide) synthase inhibitor, and these effects were reversed by L-arginine, the precursor of NO. Also, L-WAME (HG-nitro-L-arginine methyl ester) increased the basal tension. Nitroprusside, the NO-donor, suppressed the tracheal basal tension greatly. Methylene blue, the inhibitor of guanylate cyclase, decreased EFS-induced relaxations and increa ed basal tension. Forskolin and isoprenaline, which are activators of adenylate cyclase, suppressed tracheal basal tension in the same way as nitroprusside. TEA (tetraethylammonium), the non-specific K'channel blocker, and apamin, the Ca"-activated K'channel blocker, increased tracheal basal tension and EFS-induced relaxations. Our results indicate that Pr3 Is released upon stimulation of the NANC (Won Adrenergic Won Cholinergic) nerves in guinea-pig tracheal smooth muscle and that the release of NO related with the K+ channel, as well as the release of other inhibitory agents< e. g.)VIP (Vasoactive Intestinal Polypeptide), PHI (Peptide Histidine Isoleusine) > mediated via CAMP (cyclic Adenosine Monophosphate) may be Involved In sustained relaxation.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.75-76
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• 2003

Much of the recent increase in research on nicotinic ligands has been motivated by a growing body of evidence that nicotinic cholinergic pharmacology plays a role in disorder associated with deficits of cognitive function in humans. The importance of developing novel nicotinic ligands as potential therapeutics is emphasized by studies with nicotine itself that have demonstrated many useful CNS and cognitive effects in various disorders such as dementia. (omitted)

• The Korean Journal of Malacology
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• v.25 no.1
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• pp.15-22
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• 2009

Because it is known that bivalve hearts contain various modulatory systems activated by neuroendocrine substances, it was examined whether different classes of endogenous and synthetic drugs of neuroendocrinological importance can influence cardiac functions of the Pacific oyster Crassostrea gigas. Cholinergically active agents acetylcholine and carbachol increased heart rates while diminishing cardiac contractility. Adrenergically active substances norepinephrine (NE) and epinephrine (Epi) also induced heart rate increase and contractility decrease. An $\alpha_1$-adrenergic receptor-selective agonist phenyephrine (PE) failed to modulate either parameter. The Epi-induced heart rate increase and contractile depression were both blocked significantly by non-selective $\beta_1/\beta_2$-adrenergic antagonist propranolol. A $\beta_1$-selective antagonist atenolol prevented Epi-induced heart rate decrease but not the contractile depression, suggesting possible $\beta_2$ receptors for Epi-induced contractile depression. The three autacoids examined exerted discrete responses: histamine increased heart rate and depressed contraction; $\gamma$-amino-butyric acid increased both parameters; serotonin failed to change either parameter. The 5 piscine anesthetic agents examined, MS-222, benzocaine, quinaldine, urethane, pantocaine and pentobarbital, all failed to influence the cardiac function of oysters. Collectively, activities of neuroendocrinologically acting agents in mammals showed unexpected and distinct activities from those in mammalian cardiovascular systems. These results obtained from substances of different physiological functions can serve as a basis for understanding neuroendocrine control of the heart function in Pacific oyster.

• 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.