OBJECTIVE: To investigate the effect of pretreatment with neurotrophin-3 (NT-3) on intrathecal ropivacaine in rats. METHODS: A total of 144 male Sprague Dawley rats weighing 280-320 g were successfully implanted with microspinal cather following the improved methods of Yaksh. The rats were randomly divided into 4 groups and given saline (Group NS, n=36), 0.5% ropivacaine (Group M, n=36), 1% ropivacaine (Group R, n=36), and ropivacaine+NT-3 (Group T, n=36). The rats received 0.12 mL/ kg body weight of ropivacaine at 0.5% or 1%, or normal saline only, via an implanted intrathecal catheter at 90-min interval for 12 h in Group NS, M, R and T. In the meantime the rats also received NT-3 0.1 mg/kg in group T. On days 1, 3, 5, 7, 14 and 28, we assessed the paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL), behavioural change and histopathological damage score changed for possible neuronal injury within the spinal cord. RESULTS: Compared with Group NS and Group M, the PWMT and PWTL were significantly higher on 1, 3, 5 d and the histopathological damage score was significantly higher on 1, 3, 5, 7, 14 d in Group R (P<0.05). Compared with Group T, the PWMT and PWTL in Group R were significantly higher on 1, 3, 5 d and histopathological damage score was significantly higher on 5, 7, 14 d (P<0.05). CONCLUSION NT-3 pretreatment in mice has obvious protective effect against repeated intrathecal injection of 1% ropivacaine in the spinal nerve.
Amides ; adverse effects ; Animals ; Injections, Spinal ; Male ; Neurotrophin 3 ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Ropivacaine ; Spinal Cord ; drug effects

Apoptosis ; Bone Neoplasms/drug therapy* ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Humans ; Matrix Metalloproteinase 2 ; Osteosarcoma ; Ropivacaine/pharmacology*

OBJECTIVE: To observe the influence of ropivacaine on the proliferation and migration of rat bone marrow mesenchymal stem cells (BMSCs) and provide basis for the clinical application of BMSCs. METHODS: Rat BMSCs were isolated and cultured by adherence method. Surface markers of BMSCs were examined by flow cytometry. Multipotent differentiation of BMSCs was detected by induced adipogenesis, osteogenesis and muscular differentiation. Proliferation of BMSCs was examined by CCK-8 and Brdu incorporation after ropivacaine treatment at different concentrations. Migration of BMSCs was tested by cell scratch assay and Millicell experiment. RESULTS: Cultured cells had representative appearance and surface markers of BMSC, and they had potential multiple differentiation. Ropivacaine treatment at 50 and 100 μmol/L significantly reduced the proliferation rate of BMSCs and Brdu incorporation rate. There was significant difference compared with the control group (P<0.05). Cellular scratch assay and migration experiment indicated that ropivacaine significantly reduced the migration of BMSCs. There was significant difference compared with the control group (P<0.05). All these mentioned effects of ropivacaine on BMSCs were dose-dependent. There was significant difference between groups (P<0.05). CONCLUSION Ropivacaine can significantly reduce the proliferation and migration of rat BMSCs, suggesting that the influence of local anesthetics on BMSCs has to be taken into account when BMSCs are used in clinical practice.
Amides ; pharmacology ; Animals ; Bone Marrow Cells ; Cell Differentiation ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Flow Cytometry ; Mesenchymal Stem Cells ; cytology ; drug effects ; Rats ; Ropivacaine

OBJECTIVE: To observe the behaviour and Ca2+ content of spinal cord in rats after continuous spinal anesthesia administration of different densities and doses of ropivacaine in SD rats. METHODS: Twenty-four male SD rats weighing 220 approximately 280 g were anesthetized. A polyurethane microspinal catheter was inserted into the lumbar subarachnoid space 8 cm according to the method of Yaksh's. The animals were randomly divided into 4 groups of 6 each: in group N the rats were given normal saline 40 microl intrathecally every one and half hours for 3 times; in group R1, 0.5% ropivacaine was given; in group R2 0.75% ropivacaine and in group R3 1% ropivacaine was given. The activity of rats was observed. After 6 hours rats were perfused with 4% formamint through the ascending aorta. The rats were sacrificed and L1 approximately 2 segment of spinal cord was immediately removed for Ca2+ content examination. RESULTS: A total hind limbs paralysis was seen at 30 seconds and intramuscular strain gradually came back from 30 to 90 minutes after the intrathecal administration of ropivacaine in all rats. The recovery of motor black was remarkably different in group R1, R2, and R3 (P < 0.05). The Ca2+ content of spinal cord was significantly higher in group R3 than that in group R1 and R2 (P < 0.05 ). CONCLUSION There is no significant change of motor black time and it is related to drug dose for 0.5% , 0.75% and 1% ropivacaine in continuous spinal anesthesia. 1% ropivacaine may increase Ca2+ content in spinal cord.
Amides ; pharmacology ; Anesthesia, Spinal ; Animals ; Behavior, Animal ; Calcium ; metabolism ; Dose-Response Relationship, Drug ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Ropivacaine ; Spinal Cord ; metabolism

OBJECTIVE: To explore the alterations of serum of myelin basic protein (MBP) concentration in the plasma and ultrastructure in the spinal cord after continuous intrathecal injection of different ropivacaine concentrations in rats. METHODS: Ninety-six male Sprague-Dawley rats weighing 220 to approximately 280 g were randomly divided into a control group (Group N), Group R(1), R(2) and R(3) (24 rats in each group). Each group was subdivided into 4 subgroups (6 rats in each subgroup). According to the method of Yaksh's, a polyurethane microspinal catheter was inserted into the lumbar subarachnoid space in which 8 cm segment was left. Rats in each group were continuously received 40 microL of intrathecal injection of normal saline(Group N), 0.5%, 0.75%, and 1.0% ropivacaine (Group R(1),R(2),R(3)), 3 times every 1.5 hours. Blood (0.5 mL) was drawn from the femoral artery to determine serum concentrations of MBP at the detecting time T(0)(before inserted pipe)and T(1)(before the first intrathecal injection); for the subgroups, the examining time was at T(2), T(3), T(4) and T(5)(6, 12, 24 and 48 h respectively after the last time intrathecal administration). After blood was drawn, the rats in each subgroups were decapitated and the spinal cord of L(1-2) intumescentia lumbalis were immediately removed for electronic microscopic examination. RESULTS: MBP levels were comparatively steady in Group N, R(1) and R(2), while there was statistical difference between Group R(3) and Group N, R(1),R(2),and R(3) (P<0.05). MBP level of Group R(3) was significantly higher at T(2),T(3),T(4) and T(5) than that at T(0)(P<0.01). The ultrastructural changes of the spinal cord in Group R(3) were pycnosis of most neurons, dilation of most rough endoplasmic reticulum, and vague structure of mitochondria and endocytoplasmic reticulum. A few neurons were completely de-generated losing the normal structure, with vacuole degeneration of crista mitochondriales or even partial loss. CONCLUSION The spinal cord ultrastructure is selectively vulnerable after intrathecal 1.0% ropivacaine injection, which may be one of the important pathophysiological bases for local anesthetic neurotoxicity. MBP may serve as a sensitive and specific indicator of spinal cord damage after intra-thecal administration of ropivacaine.
Amides ; administration & dosage ; pharmacology ; Anesthetics, Local ; administration & dosage ; pharmacology ; Animals ; Injections, Spinal ; methods ; Male ; Myelin Basic Protein ; Nerve Tissue Proteins ; blood ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Ropivacaine ; Spinal Cord ; ultrastructure ; Transcription Factors ; blood

OBJECTIVE: To evaluate the effect of dexmedetomidine combined with ropivacaine on brachial plexus block in patients scheduled for elective shoulder arthroscopy. METHODS: Ninety patients with American Society of Anesthesiologists (ASA) I or II, scheduled for elective shoulder arthroscopy, were randomly divided into three groups. In group R (n=30), the patients were given 10 mL of 0.375% ropivacaine in branchial plexus block (interscalene approach guided by ultrasound), in group D1 (n=30), the patients were given 10 mL of 0.375% ropivacaine (interscalene approach guided by ultrasound) + dexmedetomidine 0.2 μg/(kg×h) (intravenous pump infusion), and in group D2 (n=30), the patients were given 10 mL of 0.375% ropivacaine (interscalene approach guided by ultrasound) + dexedetomidine 0.7 μg/(kg×h) (intravenous pump infusion). To evaluate the effect of brachial plexus block before general anesthesia. Group D1 and group D2 were given dexmedetomidine intravenously for 1.0 μg/kg during 10 min, then the drug was pumped by 0.2 μg/(kg×h) and 0.7 μg/(kg×h) respectively until 30 min before the operation finished. Changes in systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and before anesthesia (T0), 10 min (T1), 30 min (T2) after giving dexmedetomidine, discontinue medication (T3), after operation (T4), and extubation (T5) were investigated. Motor and sensory block onset times, block durations, and duration of analgesia were recorded. The scores of pain after operation and the adverse effects of shiver, hypopiesia, drowsiness, and blood loss were recorded during operation. RESULTS: Compared with group R, the duration of analgesia and duration of sensory block in group D1 and group D2 were significant longer (P<0.01), there was no significant difference between groups D1 and D2 (P>0.05). Compared with group R, at each time point of T1-T5, the heart rate and systolic blood pressure in group D1 and group D2 were significantly decreased (P<0.01). Compared with D1 group, the incidence of hypotension and bradycardia in group D2 were significantly different (P<0.05). CONCLUSION Intravenous dexmedetomidine could prolong the duration of analgesia time and sensory block within the brachial plexus block, inhibiting the stress response during arthroscopic shoulder surgery. Compared with high-dose, low-dose can provide safer and better clinical effect and reduce the adverse effects of dexmedetomidine.
Analgesics, Non-Narcotic ; Anesthetics, Local/therapeutic use* ; Arthroscopy ; Brachial Plexus ; Brachial Plexus Block ; Dexmedetomidine/therapeutic use* ; Double-Blind Method ; Humans ; Hypnotics and Sedatives/pharmacology* ; Prospective Studies ; Ropivacaine/therapeutic use* ; Shoulder Joint/surgery*