Expression of Myocardial Levels of Connexin 43, 40 in Experimental Dog Model of Sympathomimetic Atrial Fibrillation / 中国循环杂志

Objective: To explore the expression of myocardial levels of connexin 43(Cx43), Cx40 in experimental dog model of sympathomimetic atrial fibrillation (AF). Methods: 15 mongrels dogs were randomly divided into 3 groups: Control group, Rapid atrium pacing (RAP) group and RAP+isoprenaline (ISO) perfusion group. n=5 in each group. The hearts were taken to establish in vitro langendorff cardiac perfusion model. Atrial effective refractory period (AERP) and AF inducing rate were tested;intracellular expression and distribution of nerve growth factor (NGF) and tyrosine hydroxylase (TH) were examined by immunohistochemistry, total protein contents of Cx43 and Cx40 were measured by Western blot analysis, mitochondria morphology was observed by transmission electron microscope and mitochondria reactive oxygen species (ROS) generation was detected by fluorescent colorimetric method. Results: AERP was similar between Control group and RAP group (166±5.1) ms vs (160±3.2) ms which cannot induce AF; while it was shortened in RAP+ISO group (148±3.7) ms, P<0.05 which may successfully induce AF.Compared with Control group, mitochondria was slightly swollen in RAP group and the matrix was intact, while mitochondria was obviously swollen in RAP+ISO group and part of matrix was transparent; total protein contents of Cx43 and Cx40 were lower in both RAP group and RAP+ISO group, P<0.05; in addition, they were even lower in RAP+ISO group than RAP group, P<0.05. Compared with Control group and RAP group, RAP+ISO group had increased expression and distribution of NGF, TH and mitochondria ROS generation, P<0.05; NGF, TH and ROS in RAP group were higher than Control group, P<0.05. Conclusion: Sympathetic AF has been related to the contents and changes of myocardial levels of CX43 and Cx40; sympathetic nerve might trigger AF by oxidative stress induced down-regulation of myocardial CX43 and Cx40 in experimental dog model.

El grado de obesidad modifica la respuesta de disminución de circunferencia de cintura en pacientes que reciben 15 mg diarios de sibutramina: estudio abierto sobre tolerancia y efectividad de la sibutramina / Patients with type III obesity given sibutramine 15 mg/day lose weight in amounts proportional to those in types I and II, but waist circumferences does not decrease proportionally

Objetivo. Los pacientes con sobrepeso y las clases de obesidad I, II, III presentan diferente etiología, comorbilidad, efectos metabólicos y diferente respuesta terapéutica. En este análisis evaluamos el efecto del grado de obesidad sobre la disminución del índice de masa corporal (IMC) y la circunferencia de cintura (CC) eficacia y tolerancia de sibutramina 15mg al día. Material y métodos. Se analizó una base de datos de una muestra de 701 sujetos colectados de 47 clínicas. Los sujetos recibieron tratamiento con 15 mg de sibutramina al día. Se registró el peso, estatura y la CC en las visitas basal, 4 y 8 semanas. Resultados. Los pacientes con diferentes grados de obesidad disminuyeron proporcionalmente el IMC (p = 0.86), pero los sujetos con obesidad clase III mostraron menor disminución de la CC (p = 0.003) que los otros grupos. Los eventos adversos fueron pocos, y de menor frecuencia con grados mayores de obesidad. Discusión. La disociación de disminución de IMC y la CC puede estar relacionada al control ejercido por el sistema simpático de acuerdo con el grado de obesidad, además de la biodistribución de sibutramina. Los sujetos con IMC mayor de 40 necesitan mayor dosis para alcanzar proporcionalmente la pérdida de grasa abdominal de los otros grupos de obesos.

OBJECTIVE: The etiology, comorbidity, metabolism, and treatment response vary among overweight and obesity types I, II and III individuals. We assessed the association between obesity type with body mass index, waist circumference and tolerance to a daily dose of 15 mg of sibutramine. MATERIALS AND METHODS: A sample of 701 individuals recruited from 47 health centers was analyzed. All subjects received 15 mg of sibutramine daily for 8 weeks. Weight, height, and waist circumference were measured at day 0 and weeks 4 and 8. RESULTS: Patients in all obesity types lost proportional amounts of weight (p=0.86), but those in type IIl obesity had a smaller reduction in waist circumference than those in types I and 1 (p=0.003). Side effects of sibutramine were rarely observed. Subjects with type III obesity exhibited even fewer side effects. CONCLUSIONS: The lack of association between weight reduction and decreased waist circumference across obesity types could be related to differences in the sympathetic nervous system or to sibutramine biodistribution. Subjects with body mass index greater than 40 Kg/ m(2) required a higher dose of sibutramine in order to loose the same proportion of abdominal fat as those in other types of obesity.

EFFECT OF NALOXONE ON .KEMORRHAGIC SHOCK RELATED TO SYMPATHO-ADRENOMEDULLARY SYSTEM / 中国药理学通报

Morphine antagonist naloxone (3mg/kgiv ) induced a rise in blood pressure,pulse pressure & respiratory rate in the rat under hemorrhagic shock. It also improved the survival rate. ?Receptor antagonist pheno-xybenzamine ( 1 mg/kg iv ) or adrenalectomy abolished the beneficial effects of naloxone. Reserpine ( 1 mg/kg ip for 5 d) which depleted catecholamines of periphal sympathetic nervous system could not abolish naloxone effects. Resrpine plus adrenalectomy abolished naloxone actions again. It is suggested that the effect of naloxone on the blood pressure is mainly due to release of catecholamine from adrenalmedu-llary. The results of isolated adrenal perfusion indicated that naloxone could not induce a rise in catecholamine concentration of perfused liquid. It is suggested that the action of naloxone on catecholamine release may not be a result of direct action upontbe chromaffin cells.