Skeletal muscle adaptation to physical training and beta-adrenergic blockade in spontaneously hypertensive rats

The effects of training alone or in combination with long-term, non-selective, beta-adrenergic blockade on histochemical and biochemical properties of fast-twitch [extensor digitorum longus muscle (EDL)] and slow-twitch [soleus muscle (Sol)] muscle were analyzed in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto strain rats (WKY). Fiber type distribution of Sol was drastically modified in SHR with fewer type I fibers and more type IIA fibers. No such histochemical alterations were observed in EDL. While prolonged swimming training remained ineffective in inducing both histochemical and biochemical improvement in WKY, SHR displayed a significant enhancement of capillarization and oxidative capacity in both Sol and EDL. However, in long-term beta-blocks rats training failed to improve significantly the oxidative capacity of SHR muscles, suggesting that beta-adrenoreceptor stimulation is necessary for a fully efficient adaptation of muscular metabolism to physical training.     

“山水林田湖草沙生命共同体”耦合框架、模型与展望

“山水林田湖草沙生命共同体”系统保护与修复是我国生态文明建设的重要内容。明确生命共同体的耦合机制，是科学地进行生态保护和修复工作的关键。针对当前生命共同体耦合机制不清、理论和方法不健全的问题，从耦合的视角出发，在小流域尺度上单一生态系统内部生态要素的耦合、流域尺度上不同生态系统之间的耦合、区域尺度上人与自然的耦合三个方面进行整合，在此基础上探讨了多尺度山水林田湖草沙耦合理论，提出了一般性的山水林田湖草沙耦合理论框架。梳理并比较了当前主要的生态系统模型、景观模型、统计学模型以及复合生态系统的多模型耦合方法，综合提出了一个适用于"山水林田湖草沙生命共同体"耦合研究方法。对进一步完善山水林田湖草沙一体化保护修复提出了建议，包括：一是构建多源信息数据库，推进定量化耦合机制研究；二是开展全生命周期监测与评估，探索适应性治理路径；三是强化多元主体参与，完善协同保护机制。     

Radioimmunoassay of urinary oxytocin in man]

A radioimmunoassay (RIA) for oxytocin (OT) in urine is described. 125I-OT was prepared, and antibodies were raised in rabbits against OT coupled to bovine serumalbumine. This allowed us to set up of RIA for OT which limit of detection is 1.25 pg/tube (0.6 microU). The use of an extraction procedure using CG50 Amberlite is essential. The recovery after extraction reaches 70.5%. pH 5 is the optimum pH were urine samples must be stored. The superposition of the elution peak of endogenous OT on that of exogenous hormone is an argument in favour of the validity of such an extraction procedure. Daily urinary excretion of OT reaches 9.58 mU +/- 3.48 in 18 healthy young men.