ABSTRACT
Objective To compare the density of acetylcholine receptor (AchR) in orbicular muscle of mouth and gastrocnemius muscle and their affmity with rocuronium, trying to elucidate the mechanism for the difference in the sensitivity of the muscles innervated by facial and peripheral nerve respectively to muscle relaxant.Methods Eight pathogen-free adult male SD rats weighing 180-220 g were used in this study. Muscle strips were isolated from orbicular muscle of mouth and gastrocnemius muscle. Each muscle strip was further divided into 6 smaller and slender strips of same size using dissection microscope. One strip was stained with acetylcholinesterase to measure end-plate surface area (ESA). The other 5 strips were exposed to different concentrations of rocuronium (0, 2.5, 5.0, 7.5, 10.0μg/ml). The mean density of AchR at end-plate was obtained by AchR0/ESA. (AchR0 was defined as the number of AchR per end-plate without being exposed to rocuronium. AchRE was defined as the number of free AchR per end-plate after being exposed to different concentrations of rocuronium. ) The degree of saturation of AchR with different concentrations of rocuronium at each neuromuscular junction was calculated by (AchR0 - AchRE)/AchR0 which reflects the affinity of AchR with the rocuronium in orbicular muscle of mouth and gastrocnemius muscle. Results The density of AchR was significantly lower while the affinity with rocuronium was higher in gastrocnemius muscle than in orbicular muscle of mouth ( P ＜ 0.05). Conclusion The density of AchR is lower and the affinity of AchR at end-plate with rocuronium is significantly greater in gastrocnemius muscle innervated by sciatic nerve than in orbicular muscle of mouth innervated by facial nerve. This may explain the mechanism for different sensitivity of the muscles innervated by facial and peripheral nerves to rocuronium.
ABSTRACT
AIM: To evaluate the reliability of making a research model of coronary artery stenosis and local myocardial infarction reproduced in dog by ligating canine LAD. METHODS: We disparted 30 aged healthy cross-breed dogs [(18.5?6.7) kg] into three groups. The near part of the LAD through left minimal thoracic incision was ligated to interdict 25% (group A), 50% (group B), 75% (group C) of the flux, respectively. The changes of plasma endothelium-derived factors NO, ET-1, sP-selectin and CTnT were measured before ligation and at different time points after ligation. The expression of P-selectin gene in cardiac muscle was detected by Western blotting. The segments of distal parts of the ligated LAD were cut and pathological changes of the patches of topical cardiac muscle were observed by electronic microscope. RESULTS: After ligation, NO/ET-1, P-selectin and CTnT had significant changes in group B (P
ABSTRACT
Objective: To explore the characteristics of cell adhesion molecules (sICAM-1, sP-selectin) changes on inflammatory response during cardiopulmonary bypass, and observe the effect of intervention therapy with ligustrazine on changes of cell adhesion molecules. Methods: 32 cases of congenital heart disease were divided at random into ligustrazine group (20 cases) and control group (12 cases). Ligustrazine (5mg/kg) were added to extracorporeal circulation machine in ligustrazine group. In each group, arterial blood samples were taken at the following time-points after induction of anesthesia, 15 minutes after the start of CPB, and 2 hours, 6 hours, 12 hours, 24 hours after CPB. sICAM-1, sP-selection was measured by double antibodies sandwich enzyme-linked immunosorbent assay (ELISA). Results: Plasma levels of both adhesion molecules in both groups at baseline were in normal ranges. After CPB, levels of adhesion molecules were significantly increased in both groups. The plasma levels of sICAM-1, sP-selectin in control group were higher than in ligustrazine group (P