• Title/Summary/Keyword: anesthetized rats

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General Pharmacology of SB-31$\circledR$ (SB-31$\circledR$의 일반약리작용)

  • 박우규;천혜경;권경자;윤여생;신화섭;공재양
    • Biomolecules & Therapeutics
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    • v.5 no.4
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    • pp.369-375
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    • 1997
  • General pharmacological effects of SB-31$^{R}$, the extracts of Pulsatilla koreana, were investigated in mice, rats and guinea-pigs. Intravenous injection of SB-31 (3 and 6 ml/kg) produced almost no effect on central nervous system no effects on the general symptom and behaviors of mice, spontaneous locomotor activity, pentobarbital- induced sleeping time , rotared performance , electroshock and pentylenetertrazole -induced seizures, acetic acid-induced writhing and normal body temperature in mice. SB-31 showed little effects on the spontaneous movement of the isolated ileum and contraction induced by agonists in isolated ileum, suggesting no influence on autonomic nervous system. Administration of SB-31 also did not show any effect on blood pressure in conscious rats. However, a slight decrease in heart rate was observed at high doses (6 and 10 ml/kg) of SB-31 in conscious rats. Similarly, a slight increase in respiratory rate was observed at 6 m1/kg of SB-31 in anesthetized rats. SB-31 did not produce any effect at the dose of 3 ml/kg, but showed a tendency to increase the urinary volume at 6 ml/kg, and produced a decrease in urinary excretions of N $a_{+}$and $K_{+}$at 6 ml/kg. However, transport capacity within the gastrointestinal tract and the secretion of the gastric juice were not influenced by 6 ml/kg of SB-31. In conclusion, these results suggest that SB-31 did not pro-duce any acute effects on the central nervous system, autonomic nervous system, respiratory and circulatory systems, digestive system and kidney function at the dose of below 3 ml/kg.ml/kg.

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Ultrastructural Study on the Substantia Nigra of the Head-Irradiated Rats (머리에 방사선 상해를 받은 흰쥐 흑색질의 미세구조)

  • Bae, Hack-Gun;Yang, Nam-Gil;Ahn, E-Tay;Ko, Jeong-Sik;Park, Kyung-Ho;Kim, Jin-Gook
    • Applied Microscopy
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    • v.22 no.2
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    • pp.30-45
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    • 1992
  • An experimental study on the acute irradiation effects on the substantia nigra of head-irradiated rats were carried out. Rats anesthetized with sodium thiopental, were exposed only on their head areas with a single dose of 3,000 rads or 6,000 rads, respectively. Radiation was produced by Mitsubishi linear accelerator at the speed of 200 rads/min. Aminals were sacrificed on 6 hours, 2 days and 6 days following irradiations. By the perfusion fixation through the heart, rats were fixed with 1% glutaraldehyde-1% paraformaldehyde solution. Two hours later, brains were exposed and immersed in the same fixatives over night. Tissue blocks from subtantia nigra were punched out, and they were refixed in the 2% osmium tetroxide solution. Blocks were dehydrated through alcohol series, and embedded in the araldite mixture. Ultrathin sections were stained with uranyl acetate and lead citrate solutions, From the ultrastructural study, following results were made: 1. Six hours after irradiation, severe depletion of synaptic vesicles was occurred in the many axon terminals of the nigral neuropil. 2. Dramatical decrease of lysosomes and dense granules was observed. 3. Two days following irradiation, alterations of ribosomes, granular endoplasmic reticula, mitochondria, etc, were noticed. 4. Many of the malformations were seen to be repaired on the 6th day. 5. Above results were interpreted as follows. At the acute stage of heavy irradiation, neurotransmitters in the substantia nigra are released severely. But they are recovered within 6 days. It is concluded that acute head-irradiation may result severe disturbance of nigral motor control function during the first few days.

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Hindlimb Muscle Atrophy of Rat Induced by Neuropathic Pain (말초신경 손상에 의한 신경병증성 통증으로 유발된 쥐 뒷다리근 위축)

  • Choe, Myoung-Ae;Kim, Kyung-Hwa;An, Gyeong-Ju;Lee, Kyung-Sook;Choi, Jung-An
    • Journal of Korean Biological Nursing Science
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    • v.10 no.1
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    • pp.88-95
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    • 2008
  • Purpose: The purpose of this study was to examine the effect of neuropathic pain by peripheral nerve injury on mass and Type I and II fiber cross-sectional areas on hindlimb muscles of the neuropathic pain model rat. Method: Adult male Sprague-Dawley rats (body weight 200-220 g) were assigned to one of two groups: a neuropathic pain group (n=7) that had a ligation of the left L5 spinal nerve, a control group (n=5), a naive rat without any procedures. Withdrawal threshold, activity, body weight and food intake were measured daily. At 8 days after neuropathic pain, all rats were anesthetized and the soleus and plantaris muscles were dissected from the both hindlimbs. Body weight, food intake, muscle weight and Type I and II fiber cross-sectional area of the dissected muscles were determined. Result: The neuropathic pain group showed a significant decreases (p<.05) as compared with the control rats, in diet intake, body weight, muscle weight and Type II fiber cross-sectional area of the left (affected side) soleus and plantaris muscles, and the right (unaffected side) muscle weight of plantaris and Type II fiber cross-sectional area of the soleus muscle. Conclusion: The hindlimb muscle atrophy occurs in both affected and unaffected side due to neuropathic pain by the peripheral nerve injury. The hindlimb muscle atrophy of the affected side is more pronounced than that of the unaffected side.

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General Pharmacology of LB71350, a New HIV-1 Pretense Inhibitor

  • Kim, Hee-Jin;Oh, Jeng-In;Park, Hee-Dong;Kang, Ju-Seop;Ko, Hyun-Chul;Lee, Chang-Ho
    • Biomolecules & Therapeutics
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    • v.7 no.3
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    • pp.271-277
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    • 1999
  • Safety evaluation of LB71350, a new HIV-1 protease inhibitor, was performed in mice, rats and dogs. For the general behavior of mice, LB71350 at an oral dose of 200 mg/kg did not show any significant effects on muscle tone and locomotor activity. In terms of central nervous system, at oral doses of 200 mg/kg and 1000 mg/kg, LB71350 inhibited acetic acid-induced pain response approximately 41% and 83% of control. respectively. At oral doses of 200 mg/kg and 500 mg/kg, it reduced the rectal body temperature in rats. Pentylenetetrazole-induced seizure in mice was slightly potentiated by oral administration of LB71350 at doses ranging from 200 mg/kg to 1000 mg/Ag. Single or five day treatment of LB71350 doubled the hexobarbital- induced sleeping time in mice at oral doses ranging from 50 mg/kg to 500 mg/kg. It did not cause any effects on gastric secretion and acidity in rat at oral doses of 200 mg/kg and 1000 mg/kg and also it did not change intestinal motility in mice up to 1000 mg/kg. Blood coagulation indices such as prothrombin time (PT), activated partial thromboplastin time (aPTT), and thrombin time (TT) in rats were not affected by the treatment of LB71350 up to 500 mg/kg. LB71350 caused no significant effects on the cardiac output, stroke volume, heart rate, and mean blood pressure when infused intravenously to the anesthetized rats and dogs. Taken together, LB71350 at high oral doses caused significant pharmacological effects on the central nervous system and the hexobarbital-induced sleeping time.

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Effects of Cyclic Nucleotides and Glipizide on the Cardiovascular Response of Baclofen in the Rats (흰쥐의 척수에서 Cyclic Nucleotides 및 Glipizide가 Baclofen의 심혈관반응에 미치는 영향)

  • Koh, Hyun-Chul;Ha, Ji-Hee;Shin, In-Chul
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.6
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    • pp.647-655
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    • 1997
  • The purpose of present study is to investigate the influence of a spinal gamma-aminobutyric acid B($GABA_B$) receptor on a central regulation of blood pressure(BP) and heart rate(HR), and to define its mechanism in the spinal cord. In urethane-anesthetized, d-tubocurarine-paralyzed and artificially ventilated male Sprague-Dawley rats, intrathecal administration of drugs were carried out using injection cannula(33-gauge stainless steel) through the guide cannula(PE 10) which was inserted intrathecally at lower thoracic level through the puncture of a atlantooccipital membrane. Intrathecal injection of an $GABA_B$ receptor agonist, baclofen(30, 60, 100 nmol) decreased both BP and HR dose-dependently. Pretreatment with 8-bromo-cAMP(50 nmol), a cAMP analog, or glipizide(50 nmol), a ATP-sensitive $K^+$ channel blocker, attenuated the depressor and bradycardic effects of baclofen(100 nmol), but not with 8-bromo-cGMP(50 nmol), a cGMP analog. These results suggest that the $GABA_B$ receptor in the spinal cord plays an inhibitory role in central cardiovascular regulation and that this depressor and bradycardic actions are mediated by the decrease of cAMP via the inhibition of adenylate cyclase and the opening of $K^+$ channel.

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General Pharmacology of CJ-50005 (Hepatitis A Vaccine) (A형 간염 예방백신 CJ-50005의 일반약리작용)

  • 김영훈;최재묵;정성학;정용주;이성희;김의경;김제학;박병훈
    • Biomolecules & Therapeutics
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    • v.7 no.4
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    • pp.390-396
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    • 1999
  • CJ-50005 is a hepatitis A vaccine which is prepared by formalin inactivation of the HM175 virus cultured in human diploid MRC-5 cells. The general pharmacological properties of CJ-50005 were evaluated in various animals and in vitor system. CJ-50005 at the doses of 0.025, 0.25 and 0.75 $\mu\textrm{g}$/kg, i.m. had no effect on general behavior in mice, chemo- and electro-convulsions in mice, writhing syndrome induced by acetic acid in mice, the barbital sleeping time in mice, body temperature in rats, charcoal meal propulsion in mice and urine and electrolytes excretion in rats. In anesthetized dogs, CJ-50005(0.25 and 0.75 $\mu\textrm{g}$/kg, i.v) did not alter the respiratory rate, blood pressure, heart rate, femoral blood flow and ECG. In in vitro experiment, CJ-50005 at the concentration up to 0.02 $\mu\textrm{g}$/ml did not produce any changes in the contractions of the isolated ileum of guinea pigs caused by acetylcholine, histamine or $BaCl_2$. Since these pharmacological effects of CJ-50005 were observed at dose much greater than those in clinical use (approximately 0.025 $\mu\textrm{g}$/kg, i.m.), it is likely that this vaccine may be relatively free of undesirable effects in clinical practice.

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Functional Characteristics of Lumbar Spinal Neurons Projecting to Midbrain Area in Rats

  • Park, Sah-Hoon;Kim, Geon
    • The Korean Journal of Physiology
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    • v.28 no.2
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    • pp.113-122
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    • 1994
  • The present study was carried out to characterize the functional properties of spinomesencephalic tract (SMT) neurons in the lumbar spinal cord of urethane anesthetized rats. Extracellular single unit recordings were made from neurons antidromically activated by stimulation of the midbrain area, including the deep layers of superior colliculus, periaqueductal gray and midbrain reticular formation. Recording sites were located in laminae I-VII of spinal cord segments of L2-L5. Receptive field properties and responses to calibrated mechanical stimulation were studied in 78 SMT cells. Mean conduction velocity of SMT neurons was $19.1{\pm}1.04\;m/sec$. SMT units were classified according to their response profiles into four groups: wide dynamic range (58%), deep/tap (23%), high threshold (9%) and low threshold (3%). A simple excitatory receptive field was found for most SMT neurons recorded in superficial dorsal horn (SDH). Large complex inhibitory and/or excitatory receptive fields were found for cells in lateral reticulated area which usually showed long after-discharge. Most of SMT cells received inputs from $A{\delta}$ and C afferent fiber types. These results suggest that sensory neurons in the rat SMT may have different functional roles according to their location in the spinal cord in integrating and processing sensory inputs including noxious mechanical stimuli.

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Effects of GABAB Receptor Antagonist on the Cardiovascular Response of Adenosine A1 and Adenosine A2 Receptor Agonist in the Spinal Cord of the Rats

  • Shin, In-Chul
    • Biomolecules & Therapeutics
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    • v.13 no.3
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    • pp.138-142
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    • 2005
  • Adenosine and GABA are known to be major inhitory neurotransmitters in the central nervous system and its receptors mediate various neurophamacological effects including cardiovascular modulatory effects. Inhibitory cardiovascular effects induced by intrathecal (i.t.) administration of adenosine $A_1$ receptor agonist and its modulation by cyclic AMP was suggested by our previous report. In this experiment, we examined the modulation of cardiovascular effects of adenosine $A_1$ receptor and adenosine $A_2$ receptor by $GABA_B$ receptors antagonist in the spinal cord. I.t. administration of 10 nmol of $N^6$-cyclohexyladenosine (CHA, an adenosine $A_1$ receptor agonist), I.t. administration of 2 nmol of 5'-(N-cyclopropyl)-carboxamidoadenosine (CPCA, an adenosine $A_2$ receptor agonist), pretreatment with 5-aminovaleric acid (a $GABA_B$ receptor antagonist, 50 nmol, i.t.) prior to administration of CHA and pretreatment with 5-aminovaleric acid (a $GABA_B$ receptor antagonist, 50 nmol, i.t.) prior to administration of CPCA were performed in anesthetized, artificially ventilated Sprague-Dawley rats. I.t. administration of 50 nmol of 5-aminovaleric acid significantly attenuated the inhibitory cardiovascular effects of CHA but did not attenuated the inhibitory cardiovascular effects of CPCA. It is suggested that cardiovascular responses of adenosine $A_1$ receptor is modulated by $GABA_B$ receptor and adenosine $A_2$ receptor is not modulated by $GABA_B$ receptor in the spinal cord.

Studies on the Efficacy of Combined Preparation of Crude Drugs(XXXII) -The Effect of Shihogesikungang-tang on the Central Nervous and Cardiovascular Systems- (생약(生藥) 복합제제(複合製劑)의 약효(藥效) 연구(硏究)(제32보)(第32報) -시호계지건강탕(柴胡桂枝乾薑湯)이 중추신경계(中樞神經系) 및 순환기계(循環器系)에 미치는 영향(影響)-)

  • Yoon, Myung-Sik;Kim, Nam-Jae;Lee, Kyung-Sup;Hong, Nam-Doo
    • Korean Journal of Pharmacognosy
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    • v.17 no.4
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    • pp.272-279
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    • 1986
  • This study was conducted about the effect of Shihogesikungang-tang on the central nervous system and cardiovascular system for the investigation of its clinical effect based on the Oriental medicinal references. The results of this study were summerized as follows; Analgesic activity as evaluated by the writhing syndrome in mice was significantly noted. A decrease effect of the spontaneous movement as estimated by wheel cage method, muscle relaxant effect as evaluated by the rotor rod method and the prolonged effect of sleeping time induced by thiopental-Na were significantly shown in mice. A antipyretic activity in febrile rats induced by the endotoxin was recognized. Anti-inflammatory effect in carrageen-induced paw edema in rats was significantly noted. Negative inotropic action on the isolated heart of frogs was noted. A vasodilative action in rabbits peripheral blood vessels and hypotension in anesthetized rabbits were remarkably recognized.

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Spinal c-fos Expression in a Rat Model of Incisional Pain (흰쥐의 발바닥 절개 통증모형에서 척수 후각의 c-fos 발현)

  • Kim, Hak-Song;Yoon, Myung-Ha;Choi, Jeong-Il;Bae, Choon-Sang
    • The Korean Journal of Pain
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    • v.14 no.2
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    • pp.142-149
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    • 2001
  • Background: The expression of the proto-oncogene c-fos in spinal cord neurons following various noxious stimuli has been demonstrated in numerous studies. However, the pattern of expression of c-fos after incisional stimulus has not been evaluated. This study was designed to examine c-fos expression in an incisional pain model of rats. Methods: A 1 cm longitudinal incision was made through the skin, fascia and muscle of the plantar aspect of the hindpaw in enflurane-anesthetized rats. Withdrawal responses were measured using von Frey filaments at areas around the wound before surgery and for the next 48 hours. The expression of c-fos protein in the lumbar spinal cord was examined by immunohistochemistry. Results: After incision, c-fos was strongly expressed within laminae I, II, III, IV, V and VI ipsilateral to the incision. C-fos positive neurons were detected in the controlateral site, as well. Conclusions: These studies suggest that spinal c-fos protein may not be used as a specific marker for spinal nociceptive processing in an incisional pain model.

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