Differential expression of cardiac uncoupling proteins 2 and 3 in response to myocardial ischemia-reperfusion in rats.

AIMS: We aimed to evaluate the transcription and translation of genes for uncoupling protein 2 (UCP2) & uncoupling protein 3 (UCP3) in rat heart mitochondria of both ventricles after myocardial ischemia followed by various periods of reperfusion. MAIN METHODS: Seven groups of 8 male Wistar rats were evaluated for the effects of ischemia and also reperfusion, using Western blot of isolated mitochondrial proteins in addition to RNA extraction followed by real-time RT-PCR analysis. KEY FINDINGS: In rats with 30 min of reperfusion (R30) UCP2 protein was increased 213±33%, which is meaningfully more than the control group (P<0.001). Western blot showed increase in UCP2 protein level in groups receiving reperfusion for 60 min (R60), 120 min (R120) and 180 min (R180) as much as 152±28% (P<0.001 vs. control), 123±19% (P<0.01 vs. control) and 131±30% (P<0.01 vs. control), respectively. There was no statistically important difference in UCP2 mRNA between either right or left ventricles of ischemic and ischemia-reperfusion (IR) groups vs. control group. In the groups R180 and R240, UCP3 protein levels showed 131±27% and 102±18% increase, respectively (both P<0.001 vs. control group). However, the change in UCP3 level in other groups was not significantly different from the control group. SIGNIFICANCE: UCP2 and UCP3 protein levels are considerably increased in the ischemic area early after acute myocardial IR. The right ventricular UCP2 protein expression does not change, that is, effect of IR on UCP2 protein is a local process. However, UCP3 protein level increased both in ischemic area of the left ventricle and in non-ischemic area of the right ventricle.

Expressional profile of cardiac uncoupling protein-2 following myocardial ischemia reperfusion in losartan- and ramiprilat-treated rats.

BACKGROUND AND AIMS: The aim of this study was to investigate the early changes of cardiac uncoupling protein-2 (UCP2) expression following myocardial ischemia reperfusion in rats chronically treated with ramiprilat and losartan. METHODS: Male Wistar rats were assigned into seven groups (six in each): intact (control); sham-operated; nontreated rats subjected to ischemia and reperfusion (IR); ramiprilat-treated rats with (Ram+IR) and without ischemia (Ram); losartan treated with (Los+IR) and without ischemia (Los). Quantitative evaluation of UCP2 mRNA was carried out using real-time reverse transcription-polymerase chain reaction (RT-PCR). Mitochondria were isolated, and protein expression was quantified by Western blotting. RESULTS: In IR group: UCP2 protein but not mRNA level was increased in the ischemic area of the left ventricle (LV) (172% ± 26.7, p < 0.001 vs. LV of control). Following acute myocardial IR, UCP2 protein levels was increased in the ischemic area of the LV but not in RV, suggesting the local effect of ischemia on UCP2 expression. IR-induced overexpression of UCP2 was suppressed by ramiprilat and losartan. CONCLUSION: These findings suggest that losartan and ramiprilat can suppress UCP2 expression following myocardial IR, and by this mechanism may protect the myocardium against IR injury.

Effect of clonidine premedication on blood loss in spine surgery.

BACKGROUND: Blood loss in spine surgery is an important issue, even though it has been understudied compared with hip and knee arthroplasty. OBJECTIVES: In this study, we evaluated the effect of oral clonidine as premedication on blood loss in lumbar spine fusion surgery under anesthesia with propofol and remifentanil. PATIENTS AND METHODS: In this double-blind, randomized clinical trial, 30 patients who were undergoing lumbar spine posterior fusion surgery due to traumatic fracture were allocated randomly into 2 groups. The study group (clonidine group) received a 200-µg oral clonidine tablet 60-90 minutes before anesthesia, and the control group received placebo at the same time. Induction and maintenance of anesthesia and the mean target arterial pressure for controlled hypotension with remifentanil were the same in the 2 groups. We compared the amount of intraoperative blood loss, dose of remifentanil/hour administered, need for nitroglycerine to reach the mean target arterial pressure when remifentanil was insufficient, duration of operation, and surgeon's satisfaction of a bloodless field between groups. RESULTS: There was no statistically significant difference between groups in age (P = 0.115), sex (P = 0.439), weight (P = 0.899), operation time (P = 0.2), or American Society of Anesthesiologists physical status score (P = 0.390). Intraoperative blood loss and remifentanil dose administered per hour in the clonidine group were significantly less than in the control group (P = 0.002 and P = 0.001, respectively), but there was no significant difference in surgeon's satisfaction between groups (P = 0.169). CONCLUSIONS: As an oral premedication, clonidine can reduce surgical blood loss in lumbar spine posterior fusion surgery, even at the same levels of mean arterial pressure (MAP) with the control group. Its use can be studied in more complicated spine surgeries, such as scoliosis and spinal deformity surgeries.

Use of remifentanil and alfentanil in endotracheal intubation: a comparative study.

BACKGROUND: Opioids, such as alfentanil, are used to facilitate endotracheal intubation without the use of neuromuscular blocking agents in patients undergoing elective surgery. OBJECTIVES: The goal of this study was to evaluate the endotracheal intubation conditions when remifentanil or alfentanil was used with propofol without the application of neuromuscular blocking agents. PATIENTS AND METHODS: One hundred American Society of Anesthesiologists (ASA) grade I patients scheduled for elective surgery were enrolled in this prospective, randomized, triple-blinded study. The patients were randomized to group A (alfentanil) or R (remifentanil). In group A, alfentanil (50 mcg/kg) was intravenously injected over 10 seconds, and after 45 seconds or at the occurrence of apnea, propofol (2 mg/kg) was intravenously injected over 5 seconds. Thirty seconds after the administration of propofol, laryngoscopy and endotracheal intubation were attempted. In group R, remifentanil (5 mcg/kg) was administered instead of alfentanil. Intubation conditions, including ease of laryngoscopy, patency of the vocal cords, jaw relaxation, limb movement (1-4 score), and also, demographic data were evaluated. RESULTS: There were no demographic data differences between groups (age, weight, and sex). Further, laryngoscopy, jaw relaxation, and limb movement scores were similar in the R and A groups and there were no significant differences, but vocal cords were significantly more patent in group R than those in group A (P = 0. 028). CONCLUSIONS: The results of this study showed that remifentanil, similar to alfentanil, provided excellent conditions for endotracheal intubation when used with propofol for the induction of anesthesia; however, remifentanil improved the patency of the vocal cords to a greater extent than alfentanil.