• Title/Summary/Keyword: ICV

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Effects of Intracerebroventricular TFMPP on Rabbit Renal Function (뇌실내 TFMPP가 가토신장기능에 미치는 효과)

  • Lim, Young-Chai;Choi, Johng-Bom;Kim, Kyung-Keun;Kook, Young-Johng
    • The Korean Journal of Pharmacology
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    • v.28 no.2
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    • pp.137-146
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    • 1992
  • The central tryptaminergic system has been shown to play an important role in the regulation of renal function: $5-HT_1$ receptor mediate diuresis and natriuresis, whereas both $5-HT_2$ and $5-HT_3$ mediate antidiuresis and antinatriuresis. Recently, $5-HT_1$ receptors are further subdivided into many subtypes, and central $5-HT_{1A}$ subtype was shown to mediate diuretic and natriuretic effects. The present study was undertaken to delineate the role of $5-HT_{1B}$ subtype. Trifluoromethylphenylpiperazine (TFMPP), a selective $5-HT_{1B}$ agonist in doses ranging from 8 to $750\;{\mu}g/kg$ icv elicited diuresis, natriuresis and kaliuresis in dose-dependent fashion, with the fractional excretion of filtered Na reaching 5.44% with $250\;{\mu}g/kg$ icv. The natriuresis outlasted the transient increases in renal hemodynamics, suggesting humoral mediation in the decreased tubular Na reabsorption. Plasma concentration of atrial natriuretic peptide increased along with the natriuresis. Systemic blood pressure transiently increased. When given intravenously, no diuresis and natriuresis was elicited, indicating the central mechanism. The icv TFMPP effects were not significantly affected by icv methysergide, a nonselective $5-HT_1$ blocker. Both ketanserin and MDL 72222, selective $5-HT_2$ and $5-HT_3$ antagonists, resp., did not abolish the TFMPP effects. Nor did NAN-190, $5-HT_{1A}$ blocker, affect the TFMPP effects. These observations suggest that central $5-HT_{1B}$ receptors may play a role in the central regulation of renal function by exerting diuretic and natriuretic influences, mainly through natriuretic factors.

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Amiloride-sensitive $Na^+$ Channels Are Not Involved in the Cardiovascular Responses to Increased $Na^+$ Concentration in Cerebrospinal Fluid (뇌척수액내 $Na^+$ 농도 증가에 의한 심혈관 반응과 Amiloride 민감성 $Na^+$ Channel과의 관계)

  • Kook, Hyun;Kim, Jae-Ha;Baek, Yung-Hong
    • The Korean Journal of Pharmacology
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    • v.30 no.3
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    • pp.313-319
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    • 1994
  • This study was undertaken to investigate the relationship between the $Na^+$ channels of the cardiovascular regulation center and the responses to increased $Na^+$ concentration in the cerebrospinal fluid (CSF), by observing the effects of icv administration of the agents affecting $Na^+$ transport. Icv infusion of $200\;{\mu}l$ of 1 M NaCl produced hypertension and bradycardia in the urethane-anesthetized rabbit, and the bradycardia was inhibited and reversed to tachycardia by vagotomy. Amiloride, a $Na^+$ transport inhibitor, produced hypertension and bradycardia, which were not altered by vagotomy, and it did not affect the NaCl-induced responses. Benzamil, a derivative of amiloride with higher specificity, neither produced any cardiovascular effects by itself, nor affected the NaCl-induced responses. In vagotomized rabbits, icv amiloride reversed the NaCl-induced tachycardia to a bradycardia, but the bradycardiac effect was not altered by pretreating with NaCl. This study showed that although amiloride and benzamil slightly differ in their cardiovascular action, neither of them did affect the NaCl-induced responses. We suggest that the $Na^+$ channels which are sensitive to amiloride or benzamil in the cardiovascular regulation center are not involved in the NaCl-induced response.

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Development of New Strategies for Enzyme Replacement Therapy for Lysosomal Storage Disorders

  • Ko, Ah-Ra
    • Journal of mucopolysaccharidosis and rare diseases
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    • v.2 no.1
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    • pp.17-18
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    • 2016
  • Enzyme replacement therapy (ERT) is a well-established means of treating lysosomal storage disease (LSD). However, classical IV infusion based ERT method produces less than ideal results, especially, CNS defects and quality of life in patients. To improve these main problems of parental IV formulation for LSDs, we investigate modified ERT method and evaluated the efficacy in animal model.

Analysis of Secure Protocol for Hight Speed Wireless LAN Communication (고속 무선랜 통신을 위한 보안 프로토콜에 관한 연구)

  • 정우길;박경수;이영철
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.11a
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    • pp.265-269
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    • 2002
  • 본 논문에서는 무선랜 시스템에서 보안상의 취약점을 해소하기 위해 적용되고 있는 보안 기법들에 관해 분석하였다. WLAN에서 적용되고 있는 보안규정 WEP는 RC4 스트림 키퍼의 특징에서 오는 IV Reuse 문제 및 ICV를 생성하는 CRC-32의 선형특성에 따른 문제를 분석하고 현재 사용되는 보안기법인 액세스컨트롤의 강화와 WEP 키관리 및 VPN에서의 사용자 인증알고리즘 및 데이터 암호화기술을 분석하고, 802.11a에서 보안모델의 나아갈 방향을 제시하였다.

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The Role of Brain Somatostatin in the Central Regulation of Feed, Water and Salt Intake in Sheep

  • Sunagawa, Katsunori;Weisinger, Richard S.;McKinley, Michael J.;Purcell, Brett S.;Thomson, Craig;Burns, Peta L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.7
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    • pp.929-934
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    • 2001
  • The physiological role of brain somatostatin in the central regulation of feed intake in sheep was investigated through a continuous intracerebroventricular (ICV) infusion of somatostastin 1-28 (SRIF) at a small dose of $5{\mu}g/0.2ml/hr$ for 98.5 hours from day 1 to day 5. Sheep (n=5) were fed for 2 hours once a day, and water and 0.5 M NaCI solution were given ad libitum. Feed, water and salt intake were measured during ICV infusion of artificial cerebrospinal fluid (CSF) and SRIF. The feed intake during SRIF infusion on days 2 to 5 increased significantly compared to that during CSF infusion. Water intake, when compared to that during CSF infusion, only increased significantly on day 4. NaCI intake during SRIF infusion was not different from that during CSF infusion. Mean arterial blood pressure (MAP) and heart rate during SRIF infusion were not different from those during CSF infusion. The plasma concentrations of Na, K, Cl, osmolality and total protein during SRIF infusion were also not different from those values during CSF infusion.There are two possible mechanisms, that is, the suppression of brain SRIF on feed suppressing hormones and the direct actions on brain mechanisms controlling feed intake, explaining how SRIF works in the brain to bring about increases in feed intake in sheep fed on hay. The results indicate that brain SRIF increases feed intake in sheep fed on hay.

Transient performance behaviour of the CRW type UAV propulsion system during flight mode transition considering valve operation (CRW형식 무인항공기 추진시스템의 밸브 작동을 고려한 비행모드 전환에 따른 천이 성능특성 연구)

  • Kong Chanduk;Park Jong-Ha;Yang Soo-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • v.y2005m4
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    • pp.219-224
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    • 2005
  • In order to investigate transient behaviour of the CRW(Canard Rotor Wing) type UAV(Uninhabited Aerial Vehicle) propulsion system during flight mode transition considering flow control valve operation, the propulsion system was modelled using SIMULINK commercial program. For transient simulation of the main engine system, the ICV(Inter-Component Volume) method was applied. The valve system is to control the gas flow of the rotary duct system and the main duct system, and the analysis was performed with an assumption that the total gas mass flow of the main engine is the same as summation of the rotary duct flow and the main duct flow, and with consideration of valve loss, flow rate and effective area in valve angle variation. The performance analysis was carried out during flight mode transitions from the rotary flight mode to the fixed wing flight mode and vice versa mode at altitude of 1Km, flight Mach number 0.1 and maximum engine rpm.

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Direct Action of Genistein on the Hypothalamic Neuronal Circuits in Female Rats

  • Lee, Woo-Cheol;Lee, Sung-Ho
    • Development and Reproduction
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    • v.14 no.1
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    • pp.35-41
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    • 2010
  • Mammalian reproduction is regulated by a feedback circuit of the key reproductive hormones such as GnRH, gonadotropin and sex steroids on the hypothalamic-pituitary-gonadal axis. In particular, the onset of female puberty is triggered by gain of a pulsatile pattern and increment of GnRH secretion from hypothalamus. Previous studies including our own clearly demonstrated that genistein (GS), a phytoestrogenic isoflavone, altered the timing of puberty onset in female rats. However, the brain-specific actions of GS in female rats has not been explored yet. The present study was performed to examine the changes in the activities of GnRH neurons and their neural circuits by GS in female rats. Concerning the drug delivery route, intracerebroventricular (ICV) injection technique was employed to eliminate the unwanted actions on the extrabrain tissues which can be occurred if the testing drug is systemically administered. Adult female rats (PND 100, 210-230 g BW) were anaesthetized, treated with single dose of GS ($3.4{\mu}g$/animal), and sacrificed at 3 hrs post-injection. To determine the transcriptional changes of reproductive hormone-related genes in hypothalamus, total RNAs were extracted and applied to the semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). ICV infusion of GS significantly raised the transcriptional activities of enhanced at puberty1 (EAP-1, p<0.05), glutamic acid decarboxylase (GAD67, p<0.01) which are known to modulate GnRH secretion in the hypothalamus. However, GS infusion could not change the mRNA level of nitric oxide synthase 2 (NOS-2). GS administration significantly increased the mRNA levels of KiSS-1 (p<0.001), GPR54 (p<0.001), and GnRH (p<0.01) in the hypothalami, but decreased the mRNA levels of LH-$\beta$ (p<0.01) and FSH-$\beta$ (p<0.05) in the pituitaries. Taken together, the present study indicated that the acute exposure to GS could directly activate the hypothalamic GnRH modulating system, suggesting the GS's disrupting effects such as the early onset of puberty in immature female rats might be derived from premature activation of key reproduction related genes in hypothalamus-pituitary neuroendocrine circuit.

cAMP/PKA Agonist Restores the Fasting-Induced Down-Regulation of nNOS Expression in the Paraventricular Nucleus

  • Yoo, Sang-Bae;Lee, Seoul;Lee, Joo-Young;Kim, Bom-Taeck;Lee, Jong-Ho;Jahng, Jeong-Won
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.5
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    • pp.333-337
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    • 2012
  • Gene expression of neuronal nitric oxide synthase (nNOS) changes in the hypothalamic paraventricular nucleus (PVN) depending on feeding conditions, which is decreased during food deprivation and restored by refeeding, and phosphorylated cAMP response element binding protein (pCREB) was suggested to play a role in its regulation. This study was conducted to examine if the fasting-induced down-regulation of the PVN-nNOS expression is restored by activation of cAMP-dependent protein kinase A (cAMP/PKA) pathway. Freely moving rats received intracerebroventricular (icv) injection of cAMP/PKA activator Sp-cAMP (40 nmol) or vehicle (sterilized saline) following 48 h of food deprivation. One hour after drug injections, rats were transcardially perfused with 4% paraformaldehyde, and the PVN tissues were processed for nNOS or pCREB immunohistochemistry. Sp-cAMP significantly increased not only nNOS but also pCREB immunoreactivities in the PVN of food deprived rats. Fastinginduced down-regulation of the PVN-nNOS was restored by 1 h after the icv Sp-cAMP. Results suggest that cAMP/PKA pathway may mediate the regulation of the PVN-nNOS expression depending on different feeding conditions.

Effects of Coptidis Rhizoma and Aconiti Lateralis Preparata Radix on the Change of Plasma Corticosterone Level and Rectal Temperature Induced by LPS (LPS에 의해 유발된 염증(炎症) 스트레스에 대한 황련(黃蓮)과 부자(附子)의 효과)

  • Cho, Eun-Ho;Lee, Tae-Hee
    • The Korea Journal of Herbology
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    • v.21 no.2
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    • pp.77-85
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    • 2006
  • Objectives : We investigated the effects of Coptidis Rhizoma and Aconiti Lateralis Preparata Radix on the LPS(Lipopolysaccharide) ICV(intracerebroventricular) injection. Methods : We measured plasma corticosterone level and rectal temperature in mice induced by I.C.V. injection of LPS (100ng/mouse). Results : The results were as follows.. 1. The plasma corticosterone levels in CR-1(0.5g/kg), CR-2(1.0g/kg), CR-3(3.0g/kg) were not decreased significant comparing with the control group.(P<0.05) 2. The plasma corticosterone level in AR-1(0.5g/kg) was decreased significant comparing with the control group.(P<0.05), but AR-2(1.0g/Kg) and AR-3(3.0g/kg) were not decreased significant comparing with the control group.(P<0.05). 3. The rectal temperature in CR-1(0.5g/kg), CR-2(1.0g/kg), CR-3(3.0g/kg) was decreased significant comparing with the control group.(P<0.05) 4. The rectal temperature in AR-1(0.5g/kg), AR-2(1.0g/kg), AR-3(3.0g/kg) was not decreased significant comparing with the control group.(P<0.05) Conclusion : These data revealed that Rhizoma Coptidis might have no significant effect on inflammation stress and Aconiti Lateralis Preparata Radix(0.5g/kg/mouse) might have significant effect on inflammation stress.

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The Convergent Development of Nursing Activity Index for postoperative patient using Patient Controlled Analgesia (자가통증조절기를 사용하는 수술 후 환자를 위한 간호 활동 목록의 융합적 개발)

  • Lee, Yoon-Young
    • Journal of the Korea Convergence Society
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    • v.7 no.5
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    • pp.43-49
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    • 2016
  • The purpose of this study was done to develop a nursing activity index for postoperative patient using Patient-controlled Analgesia(PCA). The study was developed in two steps: $1^{st}$ step) nursing activity index was developed through literature review and focus-group interview. $2^{nd}$ step) the nursing activity was ratified and Intervention Content Validity(ICV) was tested. Subjects were consisted of 5anesthesiologists, 6adult/fundamental nursing professors and 1acute pain management Clinical Nurse Specialist. We identified 12 items of nursing activity for postoperative patient using PCA. The Intervention Content Validity(ICV) score for each item ranged from 0.92 to 1.0. The nursing activity index for postoperative patient using PCA would be very useful in facilitating the nursing practice.