• 제목/요약/키워드: A3 agonist

검색결과 493건 처리시간 0.028초

${\alpha}$-아드레나린 수용체의 매개에 의한 병아리 수면에 대한 약리학적 고찰 (Pharmacological Evaluation of the Mechanism of ${\alpha}-Adrenoceptor-Mediating$ Sleep in Chickens)

  • 정성훈;손의동;송철수;홍기환
    • 대한약리학회지
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    • 제20권2호
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    • pp.15-21
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    • 1984
  • Clonidine으로 고혈압을 치료시 부작용으로 진정작용이 심하게 나타나며 이는 Clonidine이 중추 ${\alpha}_2$-수용체를 흥분시켜서 일으킨 결과임이 보고되었다. 본 실험에서는 부화 $1{\sim}2$일이 된 병아리에 ${\alpha}_2$-수용체 효현제들을 주사하여 정좌반사가 소실될 때까지의 시간 및 수련시간을 관찰하였으며, 그리고 guanabenz 유도 수면에 대한 ${\alpha}_1$- 및 ${\alpha}_2$-수용체 길항제 및 opiate수용체 길항제가 어떻게 관여하는 지를 검토하고 다음과 같이 요약하였다. 1) ${\alpha}_2$-수용체 효현제중 guanabenz, clonidine, guanfacine 및 B-HT 933은 용량에 의존해서 정좌반사소실까지의 잠복시간을 감소시켰다. 그러나 B-HT 920 및 oxymetazoline은 잠복시간을 경미하게 연장시켰다. 2) ${\alpha}_2$-수용체 효현제들은 용량에 비례해서 수면시간을 증가시켰고 이들의 강도는 guanabenz>clonidine>oxymetazoline${\geq}$B-HT 933${\geq}$B-HT 920> guanfacine의 순위이었다. 3) ${\alpha}_2$-수용체 길항제들은 양에 비례해서 guanabenz 유도 수면시간을 감소시켰으며 이들의 강도는 yohimbine>rauwolscine>piperoxan${\geq}$RX 781094의 순위 이었다. 4) Ethanol 및 hexobarbital유도 수면은 yohimbine에 의해 봉쇄되지 아니하였다. 5) Guanabenz유도 수면시간에 대해서 ${\alpha}_1$-수용체 효현제인 methoxamine 및 Phenylephrine은 영향이 없었으나, ${\alpha}_1$-수용체 결항제인 Prazosin은 증가시켰다. 그러나 corynanthine은 반대로 수면시간을 현저히 감소시켰다. 이상의 결과로 보아 중추 ${\alpha}_2$-수용체의 흥분으로 병아리의 수면이 야기되고, 중추 ${\alpha}_1$-수용체의 역할에 대하여는 명백하지 않으나 ${\alpha}_2$-수용체 효현제 및 길항제의 성질을 규명하는 동물모델로서 부화 I${\sim}$2일의 병아리가 크게 유용할 것으로 시사되는 바이다.

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이스라엘잉어 장관 수축에 관여하는 약물수용체에 관한 연구 (Characterization of the drug receptors responsible for intestinal contraction in Israeli carp)

  • 윤효인;한경호;박승춘;조준형;오태광
    • 대한수의학회지
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    • 제34권3호
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    • pp.447-456
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    • 1994
  • In order to elucidate the characterization of receptors involved in inestinal motility of Israeli carp, spontaneously contracting Israeli carp intestinal preperations were prepared and mounted in the organ chambers for contraction traicings using a polygraph. Various contractile agonists were treated and their dose-response curves were constructed. $EC_{50}$ values$(pD_2)$ of each agonist on specific receptors, $pA_2$ values of competitive antagonists against some agonists, and $K_1$, values of noncompetitive antagonists against some agonists were analyzed for characterization of receptors related with the intestinal contraction. Results obtained through the experiments were summarized as follows: 1. Acetylcholine(ACh) exhibited biphasic dose-response curves: initial ACh-induced dose dependent contractions were observed in pM levels but followed by decreased response in in-between concentration levels. Dose dependent contractions reappeared in ${\mu}M$ level. The peaks in pM and ${\mu}M$ levels appeared in $10^{-13}M$ and $3{\times}10^{-5}M$, respectvely. 2. Carbachol(CaCh) exhibited dose dependent contractions from $10^{-9}M$ to $10^{-5}M$, and its $pD_2$ values were higher than those of ACh($5.60{\pm}0.11$). ACh and CaCh exhibited equiactive contractions. Nicotine had no effects on contractile responses of Israeli carp intestine. 3. ACh-induced responses were inhibited by atropine($K_1:7{\times}10^{-8}M$), a muscarinic antagonist, in a non-competitive manner. But CaCh-induced responses were inhibited by both antimuscarinic atropine($pA_2:9.52{\pm}0.14$) and selective $M_2$ antagonistic 4-DAMP($pA_2:8.16{\pm}0.09$), in competitive manners. Nicotine receptor antagonistic decamethonium and hexamethonium had no effects on ACh-and CaCh-induced contractions. Therefore, the cholinergic receptor related to intestinal motility of Israeli carp was assumed as $M_2$ type. 4. In Israeli carp intestine, 5-HT (serotonin) exhibited dose dependent contractions in concentration range from $10^{-8}M$ to $10^{-5}M$. The maximal responses, however, were corresponded to about 50% of those of ACh or CaCh. 5-HT induced contractions were inhibited by $5-HT_2$ antagonistic ketanserin ($K_1: 7.8{\times}10^{-4}M$) in a non-competitive manner, but not by both of anti $5-HT_1$, spiperone and anti $5-HT_3$, MDL-72222. Hence, $5-HT_2$ receptors are suggested to be existed in Isreli carp intestine.

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Gintonin facilitates catecholamine secretion from the perfused adrenal medulla

  • Na, Seung-Yeol;Kim, Ki-Hwan;Choi, Mi-Sung;Ha, Kang-Su;Lim, Dong-Yoon
    • The Korean Journal of Physiology and Pharmacology
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    • 제20권6호
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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.

새로운 5,6-dihydro-2-trifluoromethyl-1,4-oxathiincarboxanilide 유도체의 항균활성에 미치는 치환-phenylcarbamoyl group의 영향 (Influence of substituted phenylcarbamoyl group on the fungicidal activites of a new 5,6-dihydro-2-trifluoromethyl-1,4-oxathiincarboxanilide derivatives)

  • 성낙도;유성재;남기달;장기혁;한호규
    • 농약과학회지
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    • 제2권3호
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    • pp.64-69
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    • 1998
  • 기질(S) 화합물로 30종의 5,6-dihydro-2-trifluoromethyl-1,4-oxathiin carboxanilide 유도체들을 합성하고 벼 잎집무늬 마름병균(Rhizoctonia solani)과 밀 붉은 녹병균(Puccinia recondita)에 대한 항균활성(in vivo) 값($pI_{50}$)을 측정하였다. (S)는 잘록병균보다 밀 붉은녹병균에 대하여 보다 큰 항균활성을 나타내었으며 두 종의 균에 대하여 3-methoxy, 11, 3-iso-propyloxy, 13 및 3-iso-propyl 치환체, 25가 제일 큰 활성을 보였다. 그리고 치환(X)-phenylcarbamoyl group의 변화에 따른 물리-화학 파라미터와 항균활성($pI_{50}$)으로부터 구조-활성관계(SAR)를 검토 한 결과, 벼 잎집무늬 마름병균에 대하여는 공명효과에 따른 전자밀게(R<0)의 소수성이 큰(${\pi}>0$) m-alkyl 치환기(X)가, 그리고 밀 붉은녹병균에 대하여는 분자 분극율(Sp.Pol.)과 분자의 음하전(ABSQ<0)을 위시하여 HOMO에너지(e.v.)가 클수록(HOMO<0) 높은 항균활성을 나타내었다. 또한, 전하-조절 반응에 의한 수용체-(S)간의 상호작용과 높은 활성발현 조건들이 검토되었다.

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경막외 Morphine 부작용 치료를 위한 Nalbuphine의 적정 정주 용량 (Optimal Dose of Intravenous Nalbuphine for Treatment of Side Effects of Epidural Morphine)

  • 한찬수;최일석;김일호
    • The Korean Journal of Pain
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    • 제10권1호
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    • pp.48-53
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    • 1997
  • Background : Epidural morphine provides excellent postoperative analgesia but is often associated with side effects such as nausea, vomiting and pruritus. It has been reported that mixed agonist-antagonist, nalbuphine can reverse side effects of epidural morphine without compromising analgesia. This study was designed to compare the efficacy of each intravenous dose of nalbuphine for treatment of side effects following epidural morphine. Methods : All patients received continuous infusion(2 ml/hr) of epidural morphine-local anesthetics mixture(morphine 4 mg, 1% mepivacaine 50 ml and 0.25% bupivacaine 50 ml) following a loading dose (morphine 2 mg with 1% mepivacaine 7 ml). Patients requesting treatment for nausea, vomiting and pruritus randomly received intravenous nalbuphine 0.05 mg/kg(Group 1; n=20), 0.1 mg/kg(Group 2; n=20) or 0.15 mg/kg(Group 3; n=20). The severity of nausea, vomiting, pruritus, degree of pain, sedation and vital sign were assessed prior to and 30 min after each dose. Results : The severity of nausea, vomiting and pruritus decreased significantly in all groups(p<0.01). Pain and sedation scores were unchanged in all groups. One patient received nalbuphine 0.15 mg/kg, complained of dizziness, agitation and palpitation. His blood pressure who had increased to 170/100 after first dose. Conclusions : This study suggests that intravenous nalbuphine is good for treatment of side effects following epidural morphine, and the dose of Group 1, 0.05 mg/kg, may be recommended as an optimal dose.

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Acetylcholine Induces Hyperpolarization Mediated by Activation of $K_{(ca)}$ Channels in Cultured Chick Myoblasts

  • Lee, Do-Yun;Han, Jae-Hee;Park, Jae-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • 제9권1호
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    • pp.37-43
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    • 2005
  • Our previous report demonstrated that chick myoblasts are equipped with $Ca^{2+}$-permeable stretchactivated channels and $Ca^{2+}-activated$ potassium channels ($K_{Ca}$), and that hyperpolarization-induced by $K_{Ca}$ channels provides driving force for $Ca^{2+}$ influx through the stretch-activated channels into the cells. Here, we showed that acetylcholine (ACh) also hyperpolarized the membrane of cultured chick myoblasts, suggesting that nicotinic acetylcholine receptor (nAChR) may be another pathway for $Ca^{2+}$ influx. Under cell-attatched patch configuration, ACh increased the open probability of $K_{Ca}$ channels from 0.007 to 0.055 only when extracellular $Ca^{2+}$ was present. Nicotine, a nAChR agonist, increased the open probability of $K_{Ca}$ channels from 0.008 to 0.023, whereas muscarine failed to do so. Since the activity of $K_{Ca}$ channel is sensitive to intracellular $Ca^{2+}$ level, nAChR seems to be capable of inducing $Ca^{2+}$ influx. Using the $Ca^{2+}$ imaging analysis, we were able to provide direct evidence that ACh induced $Ca^{2+}$ influx from extracellular solution, which was dramatically increased by valinomycin-mediated hyperpolarization. In addition, ACh hyperpolarized the membrane potential from $-12.5{\pm}3$ to $-31.2{\pm}5$ mV by generating the outward current through $K_{Ca}$ channels. These results suggest that activation of nAChR increases $Ca^{2+}$ influx, which activates $K_{Ca}$ channels, thereby hyperpolarizing the membrane potential in chick myoblasts.

동방결절에서 Ouabain에 의하여 발생하는 일과성 내향전류(TI)에 관한 연구 (A Study on the Ouabain-induced Transient Inward Current(TI) in the Rabbit Sinoatrial Node)

  • 최정연;홍창의;엄융의
    • The Korean Journal of Physiology
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    • 제19권2호
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    • pp.101-111
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    • 1985
  • Transient inward current (TI) was studied by the two micro-electrode voltage clamp technique in the sinoatrial node of the rabbit. The author confirmed that in $10^{-6}$ M ouabain TI was found in the SA node and investigated the effects of ions, $(Na^+,\;K^+,\;Ca^{2+})$, $\beta-agonist$ (isoprenaline), local anesthetics (quinidine, lidocaine) and Ca-blockers ($Co^{2+}$, verapamil, diltiazem) on the TI recorded during depolarizing voltage clamp pulses to -40 and -20 mV. The results obtained were as follows ; 1) $10^{-6}M$ ouabain increased the frequency of sinus action potential and decreased the amplitude, especially overshoot of action potential. TI was induced by the depolarizing voltage clamp Pulses and the magnitude of the slow inward current (isi) decreased and the time course was slowed by the same depolarizing pulses. 2) 30% $Na^{+}$ and 24mM $K^+$ decreased by $10^{-6}M$ ouabain and 6 mM $Ca^{2+}$ and $10^{-7}M$ isoprenaline increased TI, $i_{si}$ and current oscillations. 3) Quinidine $(5\times10^{-7}M)$ reduced TI and $i_{si}$ but lidocaine $(10^6\;-10^5M)$ didn't reduced or increase TI. Current oscillations increased and isi decreased by lidocaine. 4) Ca-blockers decreased the amplitude and the frequency of sinus action potential. TI and $i_{si}$ decreased significantly but were not abolished completely at the concentrations used in this experiment. Verapamil and diltiazem had inhibitory action on TI in $2\times10^{-7}M$ concentration and showed very slow recovery after wasting out with normal Tyrode solution.

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Attenuation of Morphine Tolerance and Withdrawal Syndrome by Coadministration of Nalbuphine

  • Jang, So-Yong;Kim, Hee-Jeong;Kim, Dong-Hyun;Jeong, Myeon-Woo;Ma, Tangen;Kim, Seong-Youl;Ho, Ing K.;Oh, Sei-Kwan
    • Archives of Pharmacal Research
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    • 제29권8호
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    • pp.677-684
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    • 2006
  • Morphine has been used widely on the treatment of many types of chronic pain. However the development of tolerance to and dependence on morphine by repeat application is a major problem in pain therapy. The purpose of the present study was to investigate whether combined administration of nalbuphine with morphine affects the development of tolerance to and dependence on morphine. We hypothesize that the use of nalbuphine, ${\kappa}-agonist$ may prove to be useful adjunct therapy to prevent morphine-induced undesirable effects in the management of some forms of chronic pain. Morphine (10 mg/kg) was injected to rats intraperitoneally for 5 day. The variable dose of nalbuphine (0.1, 1.0 and 5.0 mg/kg) was administered (i.p.) in combination with morphine injection. The development of morphine tolerance was assessed by measuring the antinociceptive effect with the Randall-Selitto apparatus. The development of dependence on morphine was determined by the scoring the precipitated withdrawal signs for 30 min after injection of naloxone (10 mg/kg, i.p.). Nalbuphine did not attenuate antinociceptive effect of morphine in rats. Interestingly, combined administration of morphine with nalbuphine (10:1) significantly attenuated the development of dependence on morphine. The elevation of $[^3H]MK-801$ binding in frontal cortex, dentate gyrus, and cerebellum after chronic morphine infusion was suppressed by the coadministration of nalbuphine. In addition, the elevation of NR1 expression by morphine was decreased by the coadministration of nalbuphine in rat cortex. These results suggest that the coadministration of nalbuphine with morphine in chronic pain treatment can be one of therapies to reduce the development of tolerance to and dependence on morphine.

성조숙증 치료에 대한 임상 연구 동향 -최근 중의학 저널을 중심으로- (The Trend of Clinical Research on Treatment for Precocious Puberty - Focusing on Recent Studies in the Chinese Medical Journal CAJ -)

  • 권지현;이승연;유선애
    • 대한한방소아과학회지
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    • 제31권1호
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    • pp.63-73
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    • 2017
  • Objectives The purpose of this study is to analyze recent clinical studies on treatment for precocious puberty. Methods 28 clinical studies from January 2009 to December 2016 about precocious puberty from the China Academic Journal (CAJ), China National Knowledge Infrastructure (CNKI), were selected and reviewed: 22 case control studies and 6 case series. Results The main traditional Chinese medicine (TCM) treatment was the herbal decoctions and granules. The frequently used herbs were root of Bupleurum falcatum (柴胡), fruit of Prunella vulgaris var. aleutica (夏枯草), root stem of Anemarrhena asphodeloides (知母), dried fungus nucleus of Poria cocos (茯苓), Rehmannia glutinosa var. purpurea (生地黃), peony Paeonia suffruticosa Andrews (牧丹皮), bark of Phellodendron amurense (黃柏), roots of a plant Paeoniae lactiflora (白芍藥). On the other hand, the main western medicine (WM) for precocious puberty was Gonadotropin-releasing hormone agonist (GnRHa). Total effective rate of the TCM group was 62.96-100%, that of the WM group was 36.6-93.3% and that of the TCM-WM group was 77.8-93.75%. Conclusions Traditional Chinese medicine has been shown as an effective treatment for precocious puberty. These research results can be utilized in other clinical studies and in treatment of precocious puberty.

Regulation of chicken vanin1 gene expression by peroxisome proliferators activated receptor α and miRNA-181a-5p

  • Wang, Zhongliang;Yu, Jianfeng;Hua, Nan;Li, Jie;Xu, Lu;Yao, Wen;Gu, Zhiliang
    • Animal Bioscience
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    • 제34권2호
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    • pp.172-184
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    • 2021
  • Objective: Vanin1 (VNN1) is a pantetheinase that can catalyze the hydrolysis of pantetheine to produce pantothenic acid and cysteamine. Our previous studies showed that VNN1 is specifically expressed in chicken liver. In this study, we aimed to investigate the roles of peroxisome proliferators activated receptor α (PPARα) and miRNA-181a-5p in regulating VNN1 gene expression in chicken liver. Methods: 5'-RACE was performed to identify the transcription start site of chicken VNN1. JASPAR and TFSEARCH were used to analyze the potential transcription factor binding sites in the promoter region of chicken VNN1 and miRanda was used to search miRNA binding sites in 3' untranslated region (3'UTR) of chicken VNN1. We used a knock-down strategy to manipulate PPARα (or miRNA-181a-5p) expression levels in vitro to further investigate its effect on VNN1 gene transcription. Luciferase reporter assays were used to explore the specific regions of VNN1 targeted by PPARα and miRNA-181a-5p. Results: Sequence analysis of the VNN1 promoter region revealed several transcription factor-binding sites, including hepatocyte nuclear factor 1α (HNF1α), PPARα, and CCAAT/enhancer binding protein α. GW7647 (a specific agonist of PPARα) increased the expression level of VNN1 mRNA in chicken primary hepatocytes, whereas knockdown of PPARα with siRNA increased VNN1 mRNA expression. Moreover, the predicted PPARα-binding site was confirmed to be necessary for PPARα regulation of VNN1 gene expression. In addition, the VNN1 3'UTR contains a sequence that is completely complementary to nucleotides 1 to 7 of miRNA-181a-5p. Overexpression of miR-181a-5p significantly decreased the expression level of VNN1 mRNA. Conclusion: This study demonstrates that PPARα is an important transcriptional activator of VNN1 gene expression and that miRNA-181a-5p acts as a negative regulator of VNN1 expression in chicken hepatocytes.