Preoperative high-sensitivity troponin I and B-type natriuretic peptide, alone and in combination, for risk stratification of mortality after liver transplantation / 대한마취과학회지

Background@#Given the severe shortage of donor liver grafts, coupled with growing proportion of cardiovascular death after liver transplantation (LT), precise cardiovascular risk assessment is pivotal for selecting recipients who gain the greatest survival benefit from LT surgery. We aimed to determine the prognostic value of pre-LT combined measurement of B-type natriuretic peptide (BNP) and high-sensitivity troponin I (hsTnI) in predicting early post-LT mortality. @*Methods@#We retrospectively evaluated 2,490 consecutive adult LT patients between 2010 and 2018. Cut-off values of BNP and hsTnI for predicting post-LT 90-day mortality were calculated. According to the derived cut-off values of two cardiac biomarkers, alone and in combination, adjusted hazard ratios (aHR) of post-LT 90-day mortality were determined using multivariate Cox regression analysis. @*Results@#Mortality rate after 90 days was 2.9% (72/2,490). Rounded cut-off values for post-LT 90-day mortality were 400 pg/ml for BNP (aHR 2.02 [1.15, 3.52], P = 0.014) and 60 ng/L for hsTnI (aHR 2.65 [1.48, 4.74], P = 0.001), respectively. Among 273 patients with BNP ≥ 400 pg/ml, 50.9% of patients were further stratified into having hsTnI ≥ 60 ng/L. Combined use of pre-LT cardiac biomarkers predicted post-LT 90-day mortality rate; both non-elevated: 1.0% (21/2,084), either one is elevated: 9.0% (24/267), and both elevated: 19.4% (27/139, log-rank P < 0.001; aHR vs non-elevated 4.23 [1.98, 9.03], P < 0.001). @*Conclusions@#Concomitant elevation of both cardiac biomarkers posed significantly higher risk of 90-day mortality after LT. Pre-LT assessment cardiac strain and myocardial injury, represented by BNP and hsTnI values, would contribute to prioritization of LT candidates and help administer target therapies that could modify early mortality.

Preoperative high-sensitivity troponin I and B-type natriuretic peptide, alone and in combination, for risk stratification of mortality after liver transplantation / 대한마취과학회지

Background@#Given the severe shortage of donor liver grafts, coupled with growing proportion of cardiovascular death after liver transplantation (LT), precise cardiovascular risk assessment is pivotal for selecting recipients who gain the greatest survival benefit from LT surgery. We aimed to determine the prognostic value of pre-LT combined measurement of B-type natriuretic peptide (BNP) and high-sensitivity troponin I (hsTnI) in predicting early post-LT mortality. @*Methods@#We retrospectively evaluated 2,490 consecutive adult LT patients between 2010 and 2018. Cut-off values of BNP and hsTnI for predicting post-LT 90-day mortality were calculated. According to the derived cut-off values of two cardiac biomarkers, alone and in combination, adjusted hazard ratios (aHR) of post-LT 90-day mortality were determined using multivariate Cox regression analysis. @*Results@#Mortality rate after 90 days was 2.9% (72/2,490). Rounded cut-off values for post-LT 90-day mortality were 400 pg/ml for BNP (aHR 2.02 [1.15, 3.52], P = 0.014) and 60 ng/L for hsTnI (aHR 2.65 [1.48, 4.74], P = 0.001), respectively. Among 273 patients with BNP ≥ 400 pg/ml, 50.9% of patients were further stratified into having hsTnI ≥ 60 ng/L. Combined use of pre-LT cardiac biomarkers predicted post-LT 90-day mortality rate; both non-elevated: 1.0% (21/2,084), either one is elevated: 9.0% (24/267), and both elevated: 19.4% (27/139, log-rank P < 0.001; aHR vs non-elevated 4.23 [1.98, 9.03], P < 0.001). @*Conclusions@#Concomitant elevation of both cardiac biomarkers posed significantly higher risk of 90-day mortality after LT. Pre-LT assessment cardiac strain and myocardial injury, represented by BNP and hsTnI values, would contribute to prioritization of LT candidates and help administer target therapies that could modify early mortality.

Antiallodynic and anti-inflammatory effects of intrathecal R-PIA in a rat model of vincristine-induced peripheral neuropathy / 대한마취과학회지

Background@#Studies investigating the correlation between spinal adenosine A1 receptors and vincristine-induced peripheral neuropathy (VIPN) are limited. This study explored the role of intrathecal N6-(2-phenylisopropyl)-adenosine R-(-)isomer (R-PIA) in the rat model of VIPN. @*Methods@#Vincristine (100 μg/kg) was intraperitoneally administered for 10 days (two 5-day cycles with a 2-day pause) and VIPN was induced in rats. Pain was assessed by evaluating mechanical hyperalgesia, mechanical dynamic allodynia, thermal hyperalgesia, cold allodynia, and mechanical static allodynia. Biochemically, tumor necrosis factor-alpha (TNF-α) level and myeloperoxidase (MPO) activity were measured in the tissue from beneath the sciatic nerve. @*Results@#Vincristine administration resulted in the development of cold allodynia, mechanical hyperalgesia, thermal hyperalgesia, mechanical dynamic allodynia, and mechanical static allodynia. Intrathecally administered R-PIA (1.0 and 3.0 μg/10 μl) reversed vincristine-induced neuropathic pain (cold and mechanical static allodynia). The attenuating effect peaked 15 min after intrathecal administration of R-PIA after which it decreased until 180 min. However, pretreatment with 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, 10 μg/10 μl) 15 min before intrathecal R-PIA administration significantly attenuated the antiallodynic effect of R-PIA. This antiallodynic effect of intrathecal R-PIA may be mediated through adenosine A1 receptors in the spinal cord. Intrathecally administered R-PIA also attenuated vincristine-induced increases in TNF-α level and MPO activity. However, pretreatment with intrathecal DPCPX significantly reversed this attenuation. @*Conclusions@#These results suggest that intrathecally administered R-PIA attenuates cold and mechanical static allodynia in a rat model of VIPN, partially due to its anti-inflammatory actions.

Safety of the removal of pericardial and mediastinal drain within a different drainage volume after cardiac valvular replacement surgery: A case control study / 中国胸心血管外科临床杂志

@#Objective To assess the safety of the removal of pericardial and mediastinal drain within different drainage volume after cardiac valvular replacement surgery. Methods Between July 2013 and July 2017, 201 patients with rheumatic heart disease (CHD) were treated with valve replacement in our hospital, including 57 males and 144 females, aged 15 to 72 years. They were divided into two groups according to the amount of 24-h drainage before the drain removal: a group one with 24-h drainage volume≤50 ml (n=127) and a group two with 24-h drainage volume>50 ml (n=74). The postoperative hospital stay and the incidence of severe complications between the two groups were compared. Results There was no difference between the two groups in the baseline information or the incidence of severe pericardial effusion and tamponade, while the group two tended to have a shorter length of hospital stay after surgery (8.0 dvs.7.5 d, P=0.013). Conclusion In CHD patients undergoing valvular surgery, compared with a relatively low amount of drainage before the drain removal, drawing the tube at a greater amount of drainage (24-h drainage volume>50 ml) will shorten the length of hospital stay after cardiac surgery while incidence of severe complications remains the same.

Inhibitory effect and mechanism of epigallocatechin-3-gaUate on autogenous vein graft stenosis in rat models / 中国胸心血管外科临床杂志

@#Objective    To investigate the effect and mechanism of epigallocatechin-3-gallate (EGCG) on restenosis of the vein graft. Methods    Totally 90 Sprague-Dawley rats were randomly divided a the control group, a vein graft group and an EGCG+vein graft group. At week 1, 2 and 4, the intimal and tunica thickness of the venous graft wall was evaluated by hematoxylin-eosin staining, and the expression of Ki-67 was assessed by immunohistochemistry analysis, and then the expression of hairy and enhancer of split-1 (HES1) was measured by Western blot assay. Results    At week 2, the intimal thickness (46.76±4.89 μm vs. 8.93±0.82 μm, 46.76±4.89 μm vs. 34.24±3.57 μm), tunica thickness (47.28±4.37 vs. 16.33±1.52 μm, 47.28±4.37 vs. 36.27±3.29 μm), positive cell rate of Ki-67 (21.59%±2.29% vs. 1.12%±0.22%, 21.59%±2.29%vs. 15.38%±1.30%), expression of HES1 respectively increased in the experimental group than those in the control group and the EGCG+vein graft group (P<0.05, respectively). At week 4, the intimal thickness (66.38±6.23 μm vs. 8.29±0.79 μm,   66.38±6.23 μm vs. 48.39±4.23 μm), tunica thickness (63.27±6.18 μm vs. 15.29±1.49 μm, 63.27±6.18 μm vs. 44.63±4.49 μm), positive cell rate of Ki-67 (33.19%±3.03% vs. 1.09%±0.19%, 33.19%±3.03% vs. 24.37%±2.73%), expression of HES1 increased in the experimental group than those in the control group and EGCG+vein graft group (P<0.05, respectively). Conclusion    EGCG may inhibite restenosis of vein graft by inhibiting Notch signal pathway.

Changes and significance of serum levels of VEGF, ES, TKLK, TSP and sICAM-1 in patients with diabetic retinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

·AIM: To investigate the changes of serum levels of vascular endothelial growth factor ( VEGF ) , Endostatin (ES), thrombospondin (TSP), tissue kallikrein (TKLK) and soluble intercellular adhesion molecule-1 ( sICAM-1) in patients with diabetic retinopathy ( DR ) and its clinical significance.·METHODS:Selected 60 patients with non-proliferative diabetic retinopathy ( NPDR group ) , 60 patients with proliferative diabetic retinopathy ( PDR group ) were enrolled in this study. Sixty diabetic patients without diabetic retinopathy ( DM group ) and 60 healthy people ( control group) were also enrolled. Collection time was from January 2014 to December 2016. Serum levels of VEGF, ES, TSP, TKLK and sICAM-1 were measured and compared.·RESULTS: The levels of serum VEGF, TKLK and sICAM-1 in PDR group were significantly higher than those in NPDR group, DM group and control group ( P<0. 05). The ES of PDR group was significantly lower than that of NPDR group, DM group and control group ( P<0. 05). The levels of VEGF, TKLK and ES in the NPDR group were significantly higher than those in the DM group and the control group (P<0. 05). The serum VEGF in the NPDR group was positively correlated with the levels of ES, TKLK and sICAM-1 (P<0. 05). The serum VEGF of PDR group was positively related to the levels of TKLK and sICAM-1 (P<0. 05). There was no significant relationship between serum VEGF with ES and TSP in PDR group (P>0. 05).·CONCLUSION: The levels of serum ES, TSP, TKLK and sICAM - 1 in patients with DR have changed significantly, and the process of retinopathy has been affected by regulating the level of VEGF.

Cerebral air embolism and subsequent transient neurologic abnormalities in a liver transplant recipient following the removal of the pulmonary artery catheter from the central venous access device: a case report / 대한마취과학회지

Cerebral air embolism is a rare but potentially life-threatening complication. We experienced a living-donor liver transplant recipient who presented with unexpected cerebral air embolism and transient neurologic abnormalities that subsequently developed just after the removal of the pulmonary artery catheter from the central venous access device. One day after the initial event, the patient's neurologic status gradually improved. The patient was discharged 30 days after liver transplantation without neurologic sequelae.

Peripheral T-cell lymphoma at the injection site of influenza vaccination.

Pseudolymphomas or B‑cell lymphoma at the vaccination site have been reported by several authors. However, onset of cutaneous T‑cell lymphoma with cytotoxic features is a rare complication of vaccination. We report a 27‑year‑old man who developed a nodule and ulcer that arose at the site of injection of influenza vaccine. The neoplastic cells reacted positively for CD56, CD3, CD2, perforin, and granzyme B, but negatively for CD4, CD8, CD10, CD19, CD30, CD34, CD79, and betaF1. Molecular studies showed T‑cell receptor γ (TCR‑γ) chain monoclonal rearrangement. A diagnosis of peripheral T‑cell lymphoma, not otherwise specified (NOS) was established. The patient had high fever, progressive liver dysfunction and a rapid fatal evolution.

Intrathecal Lamotrigine Attenuates Antinociceptive Morphine Tolerance and Suppresses Spinal Glial Cell Activation in Morphine-Tolerant Rats

Glial cells play a critical role in morphine tolerance, resulting from repeated administration of morphine. Both the development and the expression of tolerance are suppressed by the analgesic lamotrigine. This study investigated the relationship between the ability of lamotrigine to maintain the antinociceptive effect of morphine during tolerance development and glial cell activation in the spinal cord. In a rat model, morphine (15 microg) was intrathecally injected once daily for 7 days to induce morphine tolerance. Lamotrigine (200 microg) was co-administered with morphine either for 7 days or the first or last 3 days of this 7 day period. Thermal nociception was measured. OX-42 and GFAP immunoreactivity, indicating spinal microglial and astrocytic activation were evaluated on day 8. Tolerance developed after 7 days of intrathecal morphine administration; however, this was completely blocked and reversed by co-administration of lamotrigine. When lamotrigine was coinjected with morphine on days 5-7, the morphine effect was partially restored. Glial cell activation increased with the development of morphine tolerance but was clearly inhibited in the presence of lamotrigine. These results suggest that, in association with the suppression of spinal glial cell activity, intrathecally coadministered lamotrigine attenuates antinociceptive tolerance to morphine.

Intrathecal Gabapentin Increases Interleukin-10 Expression and Inhibits Pro-Inflammatory Cytokine in a Rat Model of Neuropathic Pain

We examined the possible anti-inflammatory mechanisms of gabapentin in the attenuation of neuropathic pain and the interaction between the anti-allodynic effects of gabapentin and interleukin-10 (IL-10) expression in a rat model of neuropathic pain. The anti-allodynic effect of intrathecal gabapentin was examined over a 7-day period. The anti-allodynic effects of IL-10 was measured, and the effects of anti-IL-10 antibody on the gabapentin were assessed. On day 7, the concentrations of pro-inflammatory cytokines and IL-10 were measured. Gabapentin produced an anti-allodynic effect over the 7-day period, reducing the expression of pro-inflammatory cytokines but increasing the expression of IL-10 (TNF-alpha, 316.0 +/- 69.7 pg/mL vs 88.8 +/- 24.4 pg/mL; IL-1beta, 1,212.9 +/- 104.5 vs 577.4 +/- 97.1 pg/mL; IL-6, 254.0 +/- 64.8 pg/mL vs 125.5 +/- 44.1 pg/mL; IL-10, 532.1 +/- 78.7 pg/mL vs 918.9 +/- 63.1 pg/mL). The suppressive effect of gabapentin on pro-inflammatory cytokine expression was partially blocked by the anti-IL-10 antibody. Expression of pro-inflammatory cytokines was significantly attenuated by daily injections of IL-10. The anti-allodynic effects of gabapentin may be caused by upregulation of IL-10 expression in the spinal cord, which leads to inhibition of the expression of pro-inflammatory cytokines in the spinal cords.

Intrathecal Lamotrigine Attenuates Mechanical Allodynia and Suppresses Microglial and Astrocytic Activation in a Rat Model of Spinal Nerve Ligation

PURPOSE: Lamotrigine, a novel anticonvulsant, is a sodium channel blocker that is efficacious in certain forms of neuropathic pain. Recently, microglial and astrocytic activation has been implicated in the development of nerve injury-induced neuropathic pain. We have assessed the effects of continuous intrathecal administration of lamotrigine on the development of neuropathic pain and glial activation induced by L5/6 spinal-nerve ligation in rats. MATERIALS AND METHODS: Following left L5/6 spinal nerve ligation (SNL), Sprague-Dawley male rats were intrathecally administered lamotrigine (24, 72, or 240 microg/day) or saline continuously for 7 days. Mechanical allodynia of the left hind paw to von Frey filament stimuli was determined before surgery (baseline) and once daily for 7 days postoperatively. On day 7, spinal activation of microglia and astrocytes was evaluated immunohistochemically, using antibodies to the microglial marker OX-42 and the astrocyte marker glial fibrillary acidic protein (GFAP). RESULTS: Spinal-nerve ligation induced mechanical allodynia in saline-treated rats, with OX-42 and GFAP immunoreactivity being significantly increased on the ipsilateral side of the spinal cord. Continuously administered intrathecal lamotrigine (240 microg/day) prevented the development of mechanical allodynia, and lower dose of lamotrigine (72 microg/day) ameliorated allodynia. Intrathecal lamotrigine (72 and 240 microg/day) inhibited nerve ligation-induced microglial and astrocytic activation, as evidenced by reduced numbers of cells positive for OX-42 and GFAP. CONCLUSION: Continuously administered intrathecal lamotrigine blocked the development of mechanical allodynia induced by SNL with suppression of microglial and astrocytic activation. Continuous intrathecal administration of lamotrigine may be a promising therapeutic intervention to prevent neuropathy.

Interaction of Morphine and Selective Serotonin Receptor Inhibitors in Rats Experiencing Inflammatory Pain

Citalopram and paroxetine are selective serotonin reuptake inhibitors and also have antinociceptive effects. We investigated the antiallodynic and antihyperalgesic effects of intrathecally administered morphine, citalopram, paroxetine, and combinations thereof, in a rat model in which peripheral inflammation was induced by complete Freund's adjuvant (CFA). Drugs were intrathecally administered via direct lumbar puncture. Mechanical allodynia was measured using a Dynamic Plantar Aesthesiometer. Thermal hyperalgesia and cold allodynia were determined by measuring latency of paw withdrawal in response to radiant heat and cold water. Behavioral tests were run before and 15, 30, 45, and 60 min after intrathecal injection. Intraplantar injection of CFA produced mechanical allodynia, thermal hyperalgesia, and cold allodynia. Intrathecally administered morphine (0.3 or 1 microg) had antiallodynic or antihyperalgesic effects (24.0%-71.9% elevation). The effects of morphine were significantly increased when a combination of citalopram (100 microg) and paroxetine (100 microg) was added (35.2%-95.1% elevation). This rise was reversed by naloxone and methysergide. The effects of citalopram and paroxetine were also reversed by naloxone and methysergide. We suggest that the mu opioid receptor and serotonin receptors play major roles in production of the antiallodynic and antihyperalgesic effects of morphine, citalopram, paroxetine, and combinations thereof, in animals experiencing inflammatory pain.

Central venous catheter-related superior vena cava syndrome following renal transplantation: A case report / 대한마취과학회지

A 55-year-old man with end-stage renal disease had severe left ventricular dysfunction and a history of deep vein thrombosis. He underwent renal transplantation, during which a central venous catheter was inserted into the right jugular vein. The central venous pressure (CVP) exceeded 20 mmHg throughout the operation but there was no other adverse event. After surgery, although the left ventricular dysfunction improved, the CVP remained high. On postoperative day 10, the patient presented with cyanosis of the arms and redness of the face and was diagnosed with superior vena cava (SVC) syndrome, for which he underwent emergency thrombectomy and SVC reconstruction. The clinical course of this patient suggests that his end-stage renal disease-associated hypercoagulable state may have promoted thrombus formation. Moreover, placing the central venous catheter tip too deep may have encouraged thrombus formation. Repositioning the tip may have prevented this complication.

Interferon regulatory factor 4: regulate and control of lymphocyte / 国际儿科学杂志

Interferon regulatory factors(IRF)are key factors in interferon induction. IRF4, a member of the IRF family of transcription factors, is expressed in cells of the immune system where it transducers signals from various receptors to activate or repress gene expression. IRF4 expression is a key regulator for the development T helper cell subsets and B lymphocyte differentiation. A series of recent studies have further demonstrated critical functions for IRF4. This review focuses on the recent advances on roles of IRF4, including infection, autoimmune disease and immune malignancy. A better understanding of IRF4 will hopefully provide new biomark and potentially guide the design of novel therapeutic approaches.

Increased intracranial pressure after massive blood loss: A case report

A 4-year old boy with supravalvular ascending aortic stenosis underwent sliding aortoplasty. After cardiopulmonary bypass weaning, aorta suture site was torn accidentally and the patient was in hypovolemic shock. Emergency cardiopulmonary bypass was reinstituted and the aorta was repaired. After removal of the aortic clamp, bradycardia and hypertension were noted. We suspected increased intracranial pressure due to hypoxic brain damage after massive blood loss and the patient was treated to lower the intracranial pressure. Physicians should be aware of the significance of the hemodynamic change associated with increased intracranial pressure to prevent further neurologic damage.

Intrathecal lamotrigine blocks and reverses antinociceptive morphine tolerance in rats / 대한마취과학회지

BACKGROUND: Chronic administration of morphine leads to the development of tolerance. We investigated the effects of intrathecal lamotrigine on the spinal morphine tolerance in rats that are undergoing tail flick tests. METHODS: Sprague-Dawley rats were given intrathecal injections of saline 10 microl, lamotrigine 300 microg, morphine 15 microg or lamotrigine plus morphine combinations for 7 days (lamotrigine was given for days 1-7, days 1-3 or days 5-7). The acute and chronic nociceptive sensitivities were assessed using a tail flick test in which the distal 5 cm of the tail was dipped into warm water before and 30 minutes after the drug injection. With successive injections of morphine on day 8, a cumulative antinociceptive dose-response curve was constructed and the 50% effective dose (ED50) was calculated for each study group. RESULTS: The coinjection group of lamotrigine with morphine blocked the development of tolerance, as was shown by the preservation of morphine antinociception over 7 days and the concomitant decrease in the ED50 values on day 8, as compared with the morphine-alone group. Coinjection of lamotrigine blocked the development of morphine tolerance, as shown by the preservation of morphine antinociception over 7 days and the concomitant decrease in the ED50 values on day 8, as compared with the morphine-alone group. CONCLUSIONS: This study suggests that lamotrigine augments the antinociceptive action of both acute and chronic morphine therapy, and it also attenuates the antinociceptive morphine tolerance in rats.

Measurement of respiratory pulse transit time variation as an intravascular volume index in simulated hemorrhage / 대한마취과학회지

BACKGROUND: We examined the usefulness of respiratory pulse transit time (PTT) variation as an intravascular volume index in young, healthy, spontaneous, paced breathing volunteers exposed to simulated central hypovolemia by lower body negative pressure (LBNP). METHODS: With paced breathing at 0.25 Hz, beat-to-beat finger blood pressure (BP), heart rate (HR), cardiac output (CO), stroke volume (SV), total peripheral resistance (TPR), and PTT were measured non-invasively in 18 healthy volunteers. Graded central hypovolemia was generated using LBNP from 0 to -20, -30, -40, and -50 mmHg. Respiratory PTT variation (PTTV) was calculated as the difference of maximal and minimal values divided by their respective means. Respiratory-frequency PTT variability (PTTRF) using power spectral analysis was also estimated. RESULTS: During LBNP, SV, CO and PTTRF decreased, but PTT, PTTV and TPR increased significantly. PTTV did not correlate with SV changes (r = -0.08, P = 0.52), but PTTRF (r = 0.58, P < 0.01) and PTT (r = 0.43, P < 0.01) did during progressive hypovolemia. CONCLUSIONS: PTTRF is more applicable to the changes in intravascular volume than PTT and PTTV, suggesting spectral analysis of PTT might be used as a dynamic preload index in patients with spontaneous and paced breathing condition, which needs further studies.

The Antiallodynic Effects of Intrathecal Zaprinast in Rats with Chronic Constriction Injury of the Sciatic Nerve

BACKGROUND: Zaprinast is an inhibitor of phosphodiesterase 5, 6 and 9. Phosphodiesterase inhibitors could produce anti-nociceptive effects by promoting the accumulation of cGMP. We hypothesized that intrathecal zaprinast could attenuate the allodynia induced by chronic constriction injury of the sciatic nerve in rat. METHODS: Sprague-Dawley rats were prepared with four loose ligations of the left sciatic nerve just proximal to the trifurcation into the sural, peroneal and tibial nerve branches. Tactile allodynia was measured by applying von Frey filaments to the lesioned hindpaw. The thresholds for the withdrawal responses were assessed. Zaprinast (3-100microg) was administered intrathecally by the direct lumbar puncture method to obtain the dose-response curve and the 50% effective dose (ED50). Measurements were taken before and 15, 30, 45, 60, 90, 120, and 180 min after the intrathecal doses of zaprinast. The side effects were also observed. RESULTS: Intrathecal zaprinast resulted in a dose-dependent antiallodynic effect. The maximal effects occurred within 15-30 min and then they gradually decreased down to the baseline level over time in all the groups. There was a dose dependent increase in the magnitude and duration of the effect. The ED50 value was 17.4microg (95% confidence intervals; 14.7-20.5microg). No severe motor weakness or sedation was observed in any of the rats. CONCLUSIONS: Intrathecally administered zaprinast produced a dose-dependent antiallodynic effect in the chronic constriction injury neuropathic pain model. These findings suggest that spinal phosphodiesterase 5, 6 and 9 may play an important role in the modulation of neuropathic pain.

Effect of intrathecal oxcarbazepine on rat tail flick test-determined morphine tolerance / 대한마취과학회지

BACKGROUND: Repeated administration of morphine leads to characteristic tolerance. We tested the effects of intrathecal oxcarbazepine (OXC) on spinal morphine tolerance in rats using the tail flick test. METHODS: Sprague-Dawley rats received intrathecal injections of 10 microliter saline alone, or 10 microliter of solutions containing 100 microgram OXC, 15 microgram morphine, or OXC + morphine for 7 days. Different groups of rats received OXC on days 1-7, 1-3, or 5-7. The tail-flick assay was used to measure acute and chronic nociception. The nociceptive stimulus consisted of dipping the distal 5 cm of the tail into warm water before and 30 min after drug injection. On day 8, an antinociceptive dose-response curve was plotted, and the 50% effective dose for morphine (given alone) was determined for all groups. RESULTS: Morphine or OXC both produced acute antinociception; OXC + morphine resulted in a significantly larger response than obtained with morphine alone. Morphine tolerance was produced by intrathecal injection of morphine over 7 days. Co-administration of morphine and OXC completely blocked morphine tolerance, but tolerance developed when OXC injection was stopped, and morphine potency was partially restored by co-administration of OXC in tolerant rats. CONCLUSIONS: The antinociceptive effect of both acute and chronic morphine therapy is increased with intrathecal OXC, and antinociceptive morphine tolerance is attenuated in rats.

The interaction of morphine and selective serotonin reuptake inhibitors on mechanical allodynia in rats with a spinal nerve ligation / 대한마취과학회지

BACKGROUND: Nerve injury may produce a tactile allodynia. However, there are few reports regarding the interaction of morphine and selective serotonin reuptake inhibitors (SSRIs) during a neuropathic pain state. Therefore, we investigated the antiallodynic interaction between morphine and SSRIs in a rat model of neuropathic pain. METHODS: Rats were prepared with a tight ligation of the left fifth and sixth lumbar spinal nerves and chronic intrathecal catheter implantation. Mechanical allodynia was then measured by application of von Frey filaments. Morphine, citalopram and paroxetine were administered intrathecally to obtain the dose-response curves. The 50% effective dose of morphine and citalopram or paroxetine were then coadministered to evaluate the drug interaction. In addition, naloxone and methysergide were administered to examine the reversal of the antiallodynic effect. RESULTS: Intrathecal morphine produced a dose-dependent antagonism of the tactile allodynia, but intrathecal citalopram or paroxetine showed no antiallodynic effects. In addition, a morphine-citalopram or paroxetine combination produced an increase in the withdrawal threshold, but naloxone and methysergide reversed the antiallodynic effect. In addition, no interactions were observed between naloxone and citalopram or paroxetine, or morphine and methysergide. CONCLUSIONS: These results suggest that activation of both micron-opioid and serotonin receptors is required for the increased interaction to occur between morphine and SSRIs administered to reduce tactile allodynia. Thus, serotonin receptors take part in the antiallodynic action of morphine at the spinal level.