Screening, identification and functional analysis of differential expression genes in rat visual cortex after monocular deprivation by RNA-Seq technique / 中华实验眼科杂志

Objective:To screen differentially expressed genes (DEGs) in rat visual cortex after monocular deprivation by RNA sequencing technology, and to analyze the function of the DEGs.Methods:Eighteen 14-day-old SD rats were randomly divided into blank control group and monocular deprivation model group according to random number table method, with 9 rats in each group.The monocular deprivation model was established through lid suture of the right eye for 14 days.Patten visual evoked potential (PVEP) in the right eyes of the rats was recorded before and 14 days after modeling, respectively.Bilateral visual cortex tissues of the rats were dissected from the two groups, and specific genes associated with the pathogenesis of amblyopia were screened out for RNA-seq analysis.The biological functions of differentially expressed genes were evaluated by Gene Ontology (GO) enrichment analysis, and metabolic pathways involved were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis.The use and care of the animals complied with ARVO statement.This study protocol was approved by an Ethics Committee of Gansu University of Chinese Medicine (No.2016-58).Results:Compared with blank control group, the latency of P 100 wave was significantly prolonged, and the amplitude was reduced in the eyes of monocular deprivation model group (both at P<0.05). Forty DEGs in the left visual cortex and 63 DEGs in the right visual cortex were determined, among which 9 genes were overlapped.GO analysis indicated that the DEGs were mainly involved in biological processes, such as DNA-templated transcription, glutamate secretion, transcriptional regulation of RNA polymerase Ⅱ promoter, protein phosphorylation etc., as well as molecular functions, such as DNA binding, ATP binding, protein serine/threonine kinase activity, calcium ion binding, zinc ion binding, phospholipase A 2 activity, nucleic acid binding and cell components involved in the formation of intracellular and membrane of endoplasmic reticulum.The abnormal expressions of Grm2 and Pla2g2a genes might be closely associated with visual function impairment. Grm2 gene was mainly involved in visual signaling pathway processes including glutamate synapse, long-term potentiation (LTP), long-term depression (LTD) etc. Pla2g2a gene was mainly involved in α-linolenic acid metabolism and arachidonic acid pathway. Conclusions:There are abnormal expressions of genes in the bilateral visual cortices of monocular deprivation rats in the sensitive period of visual development, mainly leading to the disorder of visual signal transduction pathway.Metabolic pathway changes based on specific response gene regulation may be one of the important molecular biological mechanisms in the pathogenesis of amblyopia.

Neonatal necrotizing enterocolitis rat model attenuated by a remote ischemic preconditioning in the pregnant

Abstract Purpose: To evaluate the effect of remote ischemic preconditioning (r-IPC) administered to pregnant rats, in the ileum of newborn rats subjected to hypoxia and reoxygenation. Methods: We used three pregnant rats and their newborn rats distributed in three groups: 1) Control (C) - Newborn rats born from a pregnant rat which did not undergo any intervention; 2) Hypoxia-Reoxygenation (H/R) - Newborn rats born from a pregnant rat which did not undergo any intervention, and were subjected to hypoxia-reoxygenation; 3) Remote Ischemic Preconditioning (r-IPC) - newborn rats born from a pregnant rat which was subjected to remote ischemic preconditioning twenty-four hours before giving birth and the newborn rats were subjected to hypoxia-reoxygenation. Segments of ileum were prepared for histological analysis by HE and immunohistochemistry by the Ki67 to evaluate cell proliferation, crypt depth and villus height and evaluation of apoptosis by cleaved caspase-3. Results: The intensity of the lesions was lower in the r-IPC than in the H/R group, showing significant difference (p<0.01). The r-IPC group showed a higher proliferative activity compared to the H/R group (p<0.01), with deeper crypts (r-IPC > H/R - p < 0.05), and higher villi, showing significant difference (r-IPC > H/R - (p <0.01). The occurrence of apoptosis in the H/R group was lower in comparison to groups C and r-IPC, with significant difference (H/R < r-IPC; p<0.05). Conclusion: The remote ischemic preconditioning applied to the pregnant rat protected the ileum of newborn rats subjected to hypoxia and reoxygenation, with decreased intensity of the lesions in the ileum mucosa and preservation of proliferative activity, keeping the villus height and crypt depth similar to group C.

Improving reproducibility and external validity. The role of standardization and data reporting of laboratory rat husbandry and housing

Abstract Purpose: To identify the most relevant flaws in standardization in husbandry practices and lack of transparency to report them. This review proposes some measures in order to improve transparency, reproducibility and eventually external validity in experimental surgery experiments with rat model. Methods: We performed a search of scientific articles in PUBMED data base. The survey was conducted from august 2016 to January 2017. The keywords used were "reproducibility", "external validity", "rat model", "rat husbandry", "rat housing", and the time frame was up to January 2017. Articles discarded were the ones which the abstract or the key words did not imply that the authors would discuss any relationship of husbandry and housing with the reproducibility and transparency of reporting animal experiment. Reviews and papers that discussed specifically reproducibility and data reporting transparency were laboriously explored, including references for other articles that could fulfil the inclusion criteria. A total of 246 articles were initially found but only 44 were selected. Results: Lack of transparency is the rule and not the exception when reporting results with rat model. This results in poor reproducibility and low external validity with the consequence of considerable loss of time and financial resources. There are still much to be done to improve compliance and adherence of researchers, editors and reviewers to adopt guidelines to mitigate some of the challenges that can impair reproducibility and external validity. Conclusions: Authors and reviewers should avoid pitfalls of absent, insufficient or inaccurate description of relevant information the rat model used. This information should be correctly published or reported on another source easily available for readers. Environmental conditions are well known by laboratory animal personnel and are well controlled in housing facilities, but usually neglected in experimental laboratories when the rat model is a novelty for the researcher.

Anti-aging effect of simvastatin and telmisartan on retinas and its mechanism in rats / 中华实验眼科杂志

Background Statins has prominent roles in regulating lipids,anti-inflammation,autoxidation and protecting vascular endothelial cells.Sartans can promote cell growth and the expression of cytokines.Since the pleiotropic effects of statins and sartans on a variety of cell types,it is inferred that the two medicines can delay retinal aging.Objective This study was to explore the anti-aging effect of simvastatin and telmisartan on the physiological aging of retina.Methods Sixty-six three-month-old healthy SD rats were selected in this study,and 6 of them served as the youth group and the right eyeballs were immediately enucleated.The other rats were raised until 9-month-old in the same conditions and then randomly divided into the simvastatin group,telmisartan group and the control group with 20 rats for each group.The simvastatin of 5 mg/kg and telmisartan of 8 mg/kg were given by intragastric administration once a day in the simvastatin group and the telmisartan group until 17-month-old,and the equal amount of normal saline was used in the control group in the same way.The number of survival rats was 12 in the simvastatin group,10 in the telmisartan group and 8 in the control group.The right eyes were enucleated after heart perfusion of 4％ paraformaldehyde solution for the preparation of retinal paraffin sections.Retinal thickness was measured by pathological examination,and the expressions of the retinal neuron markers,including Thy-1,protein kinase C-α (PKC-ot),opsin and rhodopsin,were detected by immunofluorescence technique to evaluate the morphology of retinal ganglion cells (RGCs),bipolar cells as well as the thickness of the outer segment of photoreceptors.Results The retinal structure was clear in the rats of the youth group.However,the RGCs arrangement and inner segment (IS) and outer segment (OS) structure were abnormal in the simvastatin group,the telmisartan group and the control group.Compared with the rats of the youth group,the thickness of outer nuclear layer (ONL),outer plexiform layer (OPL),inner nuclear layer (INL),inner plexiform layer (IPL) and the total thickness of the aging rats were decreased,and the IS/OS thickness was increased in the simvastatin group and the telmisartan group (all at P＜ 0.01).Thy-1 stain showed that the number of RGCs was reduced in the simvastatin group,telmisartan group and the control group compared with the youth group,and that in the simvastatin group was increased in comparison with the control group (all at P＜0.01).PKC-αt stain exhibited that the density of bipolar cells was increased but the axon terminal bouton was declined in the simvastatin group,telmisartan group and the control group compared with the youth group,and the axon terminal bouton was declined in the simvastatin group compared with the youth group and the control group (all at P=0.000).Opsin and rhodopsin stains displayed that the OS thickness was increased in the simvastatin group,telmisartan group and the control group compared with the youth group,and that in the telmisartan group was reduced in comparison with the control group (all at P＜0.01).Conclusions As SD rat aging,retinal thickness is gradually attenuated and the number of RGCs is gradually declined.Although the density of bipolar cells seem to be unchanged,their synaptic connections are decreased and the OS is thicken.Simvastatin and telmisartan can delay retinal senescence by protecting retinal neurons against aging and thinning thickened OS.

Experimental models of renal dysfunction in female rats. Functional and histological aspects after unilateral nephrectomy or ligation of right renal vein with kidney preservation

ABSTRACT PURPOSE: To compare renal dysfunction after right nephrectomy and ligation of the right renal vein with preservation of kidney. METHODS: Animals' weight, pH, density, protein in urine and histological samples of the kidneys were evaluated. Fifteen female rats (Wistar) were divided into three groups. In the control group, right renal vein dissections were performed. In the second group, the right nephrectomy was performed. In the third group, the right renal vein was ligated and the kidney was preserved. Urine samples were taken before, three and seven days after the procedure. On the seventh postoperative day the kidneys were removed to histopathological study. Analysis by Student's t test was performed. RESULTS: weight loss, alterations of urine pH (p<0.05), in specific gravity, proteinuria (p<0.05) were found in groups 2 and 3; hemorrhagic infarction and edema were found after ligation of the right renal vein; changes in the left kidney were also observed on the seventh day. CONCLUSIONS:.

Alteration of TRPM8 in Dorsal Root Ganglion in Rat Model of Neuropathic Pain / 天津医药

Objective: To investigate the changes of TRPM8 expression in dorsal root ganglion(DRG) in the rat model of chronic constriction injury(CCI) of the sciatic nerve. Methods: Seventy-two male SD rats weighing 250~280 g were randomly divided into 2 groups (n = 36 each): group I (CCI) and group II (sham operation). The threshold of cold hyperalgesia, heat hyperalgesia and mechanical hyperalgesia were measured before operation (baseline) and at 1, 4, 7, 10 and 14 d after operation. Six rats were killed at each time point in each group. The L5 DRGs ipsilateral to nerve injury were dissected out for determination of transient receptor potential melastatin 8(TRPM8) by immunohistochemical assay. Results: The thresholds of cold, thermal and mechanical stimuli started to decrease at 4 d after CCI in operation group and maintained at a relatively low level until the end of experiment. The cold and thermal hyperalgesia peaked at 10 d after operation and mechanical hyperalgesia at 14 d. Immunohistochemical assay demonstrated that expression of TRPM8 were increased in L5DRG on the operated side significantly at 4 d after CCI and reached the peak at 10 d and was maintained at a high level until the end of experiment. Conclusion: The upregulation of TRPM8 in DRG involved in the mechanism of neuropathic pain.

Effects of Hypertension and Pharmacological Intervention on the Left Ventricular Remodeling in Neuroendocrine Hypertensive Rats / 天津医药

Objective: To investigate the effect of medication on left ventricular myocardial matrix remodeling in neuroendocrine hypertensive rats and the mechanism and inhibitive method thereof. Methods: A neuroendocrine hypertensive model was established with adult Wistar rat. A total of 34 rats were randomly divided into four groups: parzosin (Hα), cilazapril (Hace), pentoxifylline(Hptx) and hypertensive control group(Hc). Ten normal-tensive Wistar rats were used as normal control (Nc). The systemic blood pressure, serum procollagen type Ⅲ level, serum TNF-α level, collagen volume fraction(CVF) were detected. Results: In Hace group, systolic pressure, left ventricular weight, the levels of serum procollagen type III and TNF-α were all reduced obviously compared to those in Hc group(P < 0.05). In Hα group, the systolic pressure and left ventricular weight were reduced obviously compared to those in Hc group(P < 0.05), however, the levels of serum procollagen type III and TNF-α were higher than those of Nc group(P < 0.05). In group Hptx, the systolic pressure and left ventricular weight were not decreased, while the levels of serum procollagen typeⅢ,TNF-α and CVF were reduced to normal levels. Conclusion:The angiotensin coverting enzyme inhibitor is the effective agent to reverse myocardial fibrosis, which can be achieved mostly by the inhibition of AngⅡ. Pentoxifylline may inhibit and reverse myocardial fibrosis which correlated with inhibiting TNF-α.

The Effects of Moderate Hypothermia on the Formation of Apoptosis in Transient F degrees Cal Cerebral Ischemia Model in Rats / 대한구급학회지

BACKGROUND: Delayed neuronal injury after cerebral ischemia came major neurologic complication after stroke or cardiac arrest. Apoptosis formation after ischemia may be one of a mechanism of delayed neuronal injury. This study was conducted to evaluate the effect of moderate hypothermia on apoptosis formation after one hour of middle cerebral artery degrees Cclusion in rats. METHODS: Ten Sprague-Dawley rats (300 g) were freely fed till just before operation. Anesthesia was induced with 4 vol% isoflurane in oxygen and then maintained with 2 vol% isoflurane in oxygen. Middle cerebral artery degrees Cclusion (MCAO) was induced by intraluminal monofilament nylon with blunted tip. All rats were divided randomly into two groups. In group 1 (n=5), rectal temperature was maintained at 38 degrees C. In group 2 (n=5), rectal temperature was maintained at 32 degrees C. Rectal temperature was monitored during experiment. After 60 minutes of MCAO, intraluminal monofilament was removed and all rats were returned to cages. Brain were quickly removed and cerebral hemispheres were separated after 23 hours reperfusion. Apoptosis formation were counted with TUNEL stain. RESULTS: In group 1, after 60 minutes of MCAO and 23 hours reperfusion, 51 3.6% of hipp degrees Campal neurons were TUNEL-positive stained apoptotic cells. In group 2, TUNEL-positve neurons were 26.1 6.5% and significantly less than those of group 1 (p<0.05). CONCLUSIONS: Sixty minutes of MCAO and 23 hours reperfusion induce hipp degrees Campal neuronal apoptosis. Moderate hypothermia of 32 degrees C reduces apoptosis of hipp degrees Campal neurons after 60 minutes of MCAO and 23 hours reperfusion.

Neuroprotective Effects of Propofol, Ketamine and Propofol-ketamine after Transient Forebrain Ischemia in the Rat / 대한마취과학회지

BACKGROUND: Intravenous anesthetics such as propofol and ketamine have been known to have neuroprotective effects. However, the combination of these drug is not known. This study was conducted to determine the neuroprotective effects of propofol, ketamine or both after transient forebrain ischemia. METHODS: Twenty Sprague-Dawley rats (250-300 gm) were used. Anesthesia was induced with 4% isoflurane in oxygen and then maintained with 1 - 2% isoflurane in oxygen. Ischemic injury was induced by 10 minutes of both common carotid artery ligation and hypotension (MAP < 50 mmHg). All rats were randomly divided into four groups: group I; control group; group II; ketamine 10 mg/kg was administered 10 minutes before injury; group III; propofol (1 mg/kg/min) was administered until EEG isoelectricity; and group IV; ketamine 10 mg/kg and propofol 1 mg/kg/min was administered. The Rectal temperature was maintained at 38oC. After forebrain ischemia, neurologic scores were estimated at 1 hr, 2 hrs, 1 day and 2 days after recovery. The brain was removed 3 days after and stained with H-E stain. RESULTS: Neurologic and histologic scores of group II, III, IV were significantly lower than that of group I. However, there were no significant difference between group II, III and IV. CONCLUSIONS: Ketamine and propofol have neuroprotective effects in transient forebrain ischemia in rats. However, the combination of propofol and ketamine did not show any synergistic or additive effects.

The Development of Apoptosis and DNA Fragmentation in Transient Ischemic Model in Rats, and Roles of Dexamethasoneand Hypothermia / 대한마취과학회지

BACKGROUND: Neuronal cell death after brain ischemia occurs predominately by necrosis, whereas only a minor fraction of cell death may occur through apoptosis. Authors investigated DNA fragmentation and apoptotic morphology in the brain cell to determine whether apoptosis contributes to the progression of an ischmic lesion. This study was conducted to determine the effects of dexamethasone and hypothermia on moderate brain ischemic injury by middle cerebral artery occlusion (MCAO) in rats. METHODS: Thirty Sprague-Dawley rats (220 - 280 g) were used. Anesthesia was induced and maintained with isoflurane in oxygen. MCAO was induced by intraluminal monofilament nylon. All rats were divided randomly into three groups. In group I (n = 10), normal saline 1 ml was injected intravenously 10 minutes before MCAO. In group II (n = 10), dexamethasone 3 mg/kg was administered and in group III (n = 10), body temperature was maintained at 32degreesC. After 60 minutes of MCAO, all rats that recovered from anesthesia were returned to cages. After 24 hour reperfusion, brain tissue was quickly removed and cerebral hemispheres were separated. Lesion volumes were measured by TTC staining. TUNEL reactivity was examined in the cortical infarction lesion, and rat brain DNA was run on agarose gel electrophoresis to detect DNA fragmentation. RESULTS: Apoptosis and DNA fragmentation in the nucleus developed in the hippocampal area after transient ischemia in rats. Dexamethasone did not prevent the development of apoptosis and DNA fragmentation in transient brain ischemic rats. Moderate hypothermia could prevent the development of apoptosis and DNA fragmentation in transient brain ischemic rat. CONCLUSIONS: Apoptosis may represent a mode of ischemic cell death, and dexamethasone couldn't prevent apoptotic change in the ischemic brain insult. Moderate hypothermia (32degreesC) was a specifically effective procedure to reduce the development of apoptotic change in ischemic insults.

The Changes of Neurologic Injury and Cytokine mRNA Expression according to Spinal Ischemia Time in the Rat / 대한마취과학회지

BACKGROUND: Spinal cord ischemia initiates a deleterious cascade of biochemical events that ultimately result in an increased intracellular calcium concentration. Many papers have been published on this topic but without a clear consensus on the best way of minimizing the problem. For the further study of preventing neurological injury after spinal ischemia, the proper animal model is necessary. In this study we compared spinal ischemia time on neurologic and histopathologic outcome, and inflammatory gene expression in transient spinal ischemia. METHODS: Rats were anesthetized with halothane, and divided into 4 groups:12.5 minutes of spinal ischemia (Group 1), 15 minutes of spinal ischemia (Group 2), 17.5 minutes of spinal ischemia (Group 3), and 20 minutes of spinal ischemia (Group 4). Spinal ischemia was produced by both induced hypotension and thoracic aortic cross clamping. After spinal ischemia neurologic scores were assessed after 1, 3, 6, and 24 hours. After 24 hours, rats were euthanized and spinal cords were removed for histopathologic assessment and an assay of TNF-alpha and IL-1 mRNA. RESULTS: The neurologic scores worsened according to the ischemia time. The histopathologic scores correlated well with the neurologic scores. The TNF-alpha and IL-1 mRNA expression results of group 2 were larger than those of group 1. There were no significant differences between group 2, group 3, and group 4. CONCLUSIONS: Inflammatory gene expressions are increased during transient spinal ischemia. After 15 minutes of ischemia, no further increase of mRNA expression was shown. The 15 minutes of spinal ischemia was sufficient for the spinal ischemic study in rats.

Effects of Ketamine on Carbachol and Epidermal Growth Factor Contraction in Rat Trachea / 대한마취과학회지

BACKGROUND: It is well known that ketamine, a dissociative anesthetic, inhibits smooth muscle contractions induced by high KCl and receptor agonists such as carbachol, histamine and endothelin. It has been reported that the inhibitory effect is mediated by a decrease in Ca2+ influx through the plasma membrane in smooth muscle. However, the mechanism of action for ketamine is not fully understood. In the present study, the effect of ketamine on Ca2+ -dependent and -independent carbachol and epidermal growth factor (EGF) contractions was investigated in rat tracheal smooth muscle. METHODS: Tracheal smooth muscle strips from Sprague-Dawley rats were mounted in an organ bath with physiological salt solution (PSS, pH 7.4, 37oC). When high KCl and carbachol (1, 10 micrometer) induced contraction and verapamil and ketamine attenuated contraction, and when EGF or carbachol alone and EGF plus carbachol in Ca2+ free media induced contration and verapamil and ketamine inhibited contration, the changes in tention of the muscle strips were measured. RESULTS: 1) Ketamine inhibited the contractions stimulated by high KCl (70 mM) and carbachol (1, 10 micrometer) in a concentration-dependent manner. The inhibitory effect was more marked in the 1 micrometer carbachol preparation than in the 10 micrometer carbachol preparation. 2) Although the contraction induced by carbachol (1 micrometer) was attenuated by verapamil (10 micrometer), a voltage-dependent Ca2+ channel blocker, the degree of inhibition was not complete, but only partial. The verapamil-insensitive portion of the contraction induced by carbachol was completely inhibited by the cumulative application of ketamine. 3) EGF (1 mg/ml), a tyrosine kinase-associated growth factor, or carbachol alone did not induce contraction in Ca2+ -free PSS (1 mM EGTA). However EGF plus carbachol contracted tracheal smooth muscle in the Ca2+ -free media and it was completely inhibited by ketamine but not by verapamil. CONCLUSIONS: These results suggest that ketamine inhibits the smooth muscle contraction including both verapamil-sensitive and -insensitive Ca2+ increments and by Ca2+ -independent contraction mechanisms.

The Effect of Hypertonic Saline and Mannitol against Edema Formation after Cryogenic Brain Injury in Rats / 대한마취과학회지

BACKGROUND: After experimental cryogenic cerebral injury, severe focal brain contusion develops due to blood-brain barrier breakdown and vasogenic cerebral edema formation. This study has been conducted to find out the effects of hypertonic saline against cryogenic brain edema in rats. METHODS: Thirty rats of either sex weighing 250 to 300 g underwent a 60 seconds of cryogenic brain injury. All rats were randomly divided into one of three groups; control group (n = 10), 7.5% saline group (n = 10), and 10% mannitol group (n = 10). The water contents were measured 60 minutes after cryogenic injury by using the dry-weight method. RESULTS: The water contents in the 7.5% saline and 10% mannitol groups were significantly decreased compared with the control group. The levels of edema in the 7.5% saline and 10% mannitol groups were also significantly decreased compared with the control group. Although it appeared as if that 10% mannitol might decrease edema formation more than 7.5% saline, there were no statistical differences between the 7.5% saline and 10% mannitol groups. CONCLUSIONS: Hypertonic saline (7.5%) may be as effective agent to reduce edema formation after brain trauma to the same degree as mannitol.

The Effects of Isoflurane on the Expression of iNOS mRNA in Endotoxemic Rats / 대한마취과학회지

BACKGROUND: It has been known that alveolar macrophage exposed to bacterial lipopolysaccharide (LPS) induces a lots of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) mRNA expression. The Authors elucidated the effects of iNOS mRNA expression by inhalational anesthetics (isoflurane) on endotoxemic rats and positive pressure ventilation with and without LPS. METHODS: Fifty Sprague-Dawley rats (250 - 270 g) were anesthesized with urethane injected in the peritoneal cavity. Then the expression of iNOS mRNA in the alveolar macrophages of the rats were measured after injection of LPS, 2 hours of isoflurane (0.5 - 2.5%) anesthesia, and 2 hours of positive pressure ventilation. The activities of iNOS in macrophages were measured by analysing iNOS mRNA expression by Northern blot analysis with autoradiography using the polymerase chain reaction (PCR) method. RESULTS: The size and patterns of the iNOS mRNA band in the 0.5 - 2% isoflurane group were almost same as with the control group. The size of the iNOS mRNA band in the 2.5% isoflurane group increased more than in the control group. In the continous positive-pressure ventilation with LPS group, the iNOS mRNA band was slightly increased compared to the normal lung and the continous positive-pressure ventilation without LPS group. CONCLUSIONS: Higher concentrations of isoflurane anesthesia may evoke the expression of iNOS mRNA in a septic model. Positive pressure ventilation in sepsis may induce iNOS mRNA production.

The Role of the Glutamate Receptor in the Transient Focal Cerebral Ischemia in Rats / 대한마취과학회지

BACKGROUND: To investigate the role of glutamate in the transient focal cerebral ischemia, a reversible middle cerebral artery occlusion model was induced in 25 male Sprague-Dawley rats. METHODS: Triphenyltetrazolium chloride (TTC) stain was used for evaluation of the changes of infarction ratio in MK-801 (0.3, 1.0, 3.0 mg/kg) or pentylenetetrazole (50 mg/kg) treated groups. RESULT: The infarction ratio at 48 hours after 2 hour transient focal brain ischemia was 39.2 +/- 13.2% in control group and 23.8 +/- 4.2, 27.0 +/- 8.9, and 12.8 +/- 4.4% in MK-801 (0.3, 1.0, 3.0 mg/kg) groups. In the pentylenetetrazole (PTZ) group, the infarction ratio was 32.6 +/- 6.7%. CONCLUSIONS: The non-specific glutamate receptor antagonist, MK-801, showed a trend toward dose-dependent improvement, but the PTZ group showed no improvement. From these results, it suggested that glutamate might be partly involved in the mechanisms of ischemia-induced neuronal damage.

The Effects of Dexamethasone and MK-801 on Edema Formation in Middle Cerebral Artery Occlusion Model of the Rat / 대한마취과학회지

BACKGROUND: This study was conducted to determine the effects of dexamethasone and MK-801 on the formation of brain edema resulting from a focal ischemic injury by middle cerebral artery occlusion in rats. METHODS: Fifteen Sprague-Dawley rats (220 280 g) were freely allowed to drink and eat until just before surgery. Anesthesia was induced with 4% isoflurane in oxygen and then maintained with 2% isoflurane in oxygen. Ischemic injury was induced by an intraluminal suture with a blunted tip inserted into the internal carotid artery and occlusion of the middle cerebral artery. All rats were divided randomly into three groups. In group I (n = 5), normal saline 1 ml was injected intravenously 10 minutes before MCA occlusion. In group II (n = 5), dexamethasone 3 mg/kg was administered 10 minutes before injury. In group III (n = 5), a N-methyl-D-aspartate receptor antagonist, MK-801 1 mg/kg was injected 30 minutes before injury. Rectal temperatures were monitored during the experiment. After 60 minutes of MCA occlusion, the intraluminal sutures were removed and all the rats were returned to their cages. Their brain were quickly removed and the cerebral hemispheres were sepaerated into ischemic cores and penumbra zones after 1 hour of reperfusion. The separated cerebral hemispheres were dried 7 days at 60oC dry oven. The cerebral water content was assessed by the dry-weight method. RESULTS: In the dexamethasone group, there were no significant changes in cerebral edema formation in both ischemic core and the penumbra. In the MK-801 group, there were significant reductions in the brain edema formation in the penumbra (P< 0.05), but not in the core. CONCLUSIONS: Dexamethasone has no effect on ischemic brain edema; however, MK-801 is effective in the ischemic penumbra zone by reducing of edema formation.

A Study of iNOS Expression in the Alveolar and NO Concentrations in the Peritoneal Macrophage by Various Anesthetics in the Endotoxemic Rats / 대한마취과학회지

BACKGROUND: It is a well known phenomenon that alveolar and peritoneal macrophages exposed to bacterial lipopolysaccharide (LPS) induce a large output of nitric oxide (NO) and an inducible nitric oxide synthase (iNOS) m-RNA expression. The author elucidate the effects on NO production and iNOS m-RNA expression of various anesthetics, inhalational (halothane, enflurane, sevoflurane) and intravenous (ketamine, propofol), on endotoxemic rats. METHODS: To examine the production of NO in peritoneal macrophages, NO concentrations were measured from the rats following 2 hours exposure to LPS and 2 hours administration of various anesthetics, respectively. Culture supernatants were collected 24 hours after exposure to LPS and anesthetics and assayed by ELISA (Enzyme Linked Immunosorbent Assay) for production of NO. iNOS m-RNA expression was measured using PCR (Polymerase Chain Reaction) techniques and autoradiography. RESULTS: In the control group, the NO concentration was measured at 120 minutes after infusion of LPS to rats, and showed 12+/-4 micrometer. After insufullation of anesthetics to experimental animals, NO concentration increased in the halothane, enflurane, sevoflurane, propofol, and ketamine groups, 132+/-27 (P< 0.05), 49+/-19 (P< 0.05), 23+/-14 (P< 0.05), 37+/-11 (P< 0.05), and 17+/-2 micrometer respectively. The size and brightness of the iNOS m-RNA bands were large in halothane, enflurane, sevoflurane, propofol and ketamine, in order. CONCLUSIONS: Intravenous anesthetics showed more stability than inhalation anesthetics with regand to production of NO and iNOS m-RNA expression in sepsis on rats. The mechanism is not clear, but it is related to the strong stimulating effect to the airway tract in from inhalational anesthetics.

Effect of Propofol and Thiopental on the Isolated Stunned Rat Heart / 대한마취과학회지

BACKGROUND: Propofol(2,6-diisopropyl phenol) is an intravenous anesthetic agent, which was first introduced in 1986. It has 178.27 molecular weight and 1.8 fold stronger action of induction than that of thiopental. The effect of propofol, lowering blood pressure by depressing the cardiovascular system, has been mentioned in many papers, but its effect on myocardium is still in controversy and differs according to the method and interpretation of experiments used. This animal experiment was conducted to compare the effects of propofol and thiopental on myocardial contractility and coronary flow in isolated stunned rat hearts. METHOD: The hearts were isolated from twenty-four Sprague-Dawley rats and were perfused with modified Krebs solution. After isolation, the hearts were left in stabilizing period for 30 minutes. Then, myocardial stunning was induced by global ischemia for 15 minutes. In Group I, propofol was added to modified Krebs solution, which was used to perfuse the hearts at 40, 80, 120, 160, and 200micrometer concentration. In Group II, thiopental was added to perfusate at same concentration. Between each perfusion with anesthetic-added solution, the hearts in both groups were perfused with normal Krebs solution for 30 minutes to eliminate cumulative effect of anesthetics added. Left ventricular pressure, rate of ventricular pressure generation(dP/dt), and coronary flow were measured. RESULT: In both groups, anesthetics reduced left ventricular pressure and dP/dt in a dose dependent fashion. These changes were not statistically significant between two groups. However, at the 40 and 80micrometer concentration, the increment of coronary flow by propofol was significantly larger than that by thiopental. At the 120, 160, and 200micrometer concentration of propofol, coronary flow was gradually decreased with increasing concentration, and these decrease in coronary flow were not statistically significant between two groups. CONCLUSION: The effects of propofol on myocardial function were similar to those of thiopental in isolated stunned rat hearts and the increment of coronary flow might develop the coronary stealphenomenon. So, propofol may not have the benefit compare to thiopental for cardiac function.

Effects of Aprotinin and Insulin on Regulation of Inducible Nitric Oxide Synthase m-RNA in the Mouse Macrophage / 대한마취과학회지

BACKGROUND: Nitric oxide (NO) has been known to have antimicrobial activity, and the increased NO production in case of sepsis may play as a physiologic defense mechanism. However the increased formation of NO by the inducible nitric oxide synthase (iNOS) has been known to be implicated in pathophysiology of a variety of disease, including circulatory and septic shock. We measured the iNOS activities of mouse macrophage after application of various drugs with lipopolysaccharide (LPS) and gamma-interferon (IFN). The purpose of this study is to evaluate the inhibiting properties of various drugs to iNOS in case of sepsis. METHOD: Thirty ICR (Institue for Cancer Research) mouse weighting 30~40 gm were anesthetized with diethyl ether, and thiogycol broth was injected into peritoneal cavity. Two days later macrophages were collected from peritoneal cavity, and incubated for 24 hours in the CO2 incubator with LPS and IFN mixture and various concentration of dexamethasone, pentoxifylline, aspirin, aprotinin, regular insulin (RI) and neutral protamine hagedorn insulin (NPH). NO concentration were calculating by measuring nitrite concentration which represent the magnitude of NO production. The activities of iNOS in macrophages were measured by analysing iNOS m-RNA expression by Northern blot analysis with autoradiography using polymerase chain reaction (PCR) method. RESULT: The basic NO concentration was 13.0 +/- 8.0 micrometer. With LPS and IFN, NO concentration was increased to 104.4 +/- 31.9 micrometer. The increase in NO production by LPS and IFN was attenuated by dexamethasone (10 (-6) M only), pentoxifylline (above 10 (-10) M), aprotinin, RI, and NPH in dose dependent manner. The addition of LPS and IFN in the culture media caused increase in the iNOS m-RNA production. The aprotinin, RI, and NPH attenuated the increase in iNOS m-RNA production by LPS and IFN. Coclusion: These results suggest that the aprotinin, RI, and NPH prevent the LPS and IFN induced increase of NO production by attenuating the iNOS activity. These properties of aprotinin and insulin may be applied to the treatment of septic shock to block the enhanced formation of NO production.