Golgi tendon organ reflex inhibition following manually applied acute static stretching

Abstract

Golgi tendon organ disinhibition may contribute to exercise-associated muscle cramp (henceforth referred to as “cramps”) genesis. Static stretching pre-exercise is prescribed to prevent cramps based on the assumption golgi tendon organ inhibition remains elevated post-stretching. We determined whether stretching increased gastrocnemius golgi tendon organ inhibition and, if so, the time course of this inhibition post-stretching. Twelve participants’ dominant limb medial gastrocnemius inhibition was measured before, and at 1, 5, 10, 15 and 30 min after investigators applied three, 1-min duration stretches. Participants maintained voluntary contraction intensities of 5% of their maximum while the Achilles tendon was stimulated transcutaneously 50 times. Five-hundred millisecond epochs of raw electromyographic activity were band-pass filtered, full-wave rectified and averaged. An algorithm identified inhibitory points and calculated the area, maximum and duration of inhibition. Area of inhibition (F_1,14 = 1.5, P = 0.25), maximum inhibition (F_1,14 = 0.2, P = 0.72) and duration of inhibition (F_1,14 = 1.5, P = 0.24) were unaffected by static stretching over the 30-min post-stretching period. If pre-stretching does prevent fatigue-induced cramping, the mechanism is unlikely to involve the autoinhibition produced by the golgi tendon organ reflex. Further empirical research is needed to validate the proposed link between static stretching and cramping and then to investigate alternative mechanisms.     

一种真菌蛋白促进黄瓜生长研究初探

以黄瓜为试验材料,用中国农科院邱德文博士从真菌中分离出的真菌蛋白进行处理,过一段时间,对根系脱氢酶、纤维素酶、RUBP羧化酶的活性以及叶绿素、生长素含量进行测定。结果表明:经真菌蛋白处理的黄瓜根系脱氢酶、纤维素酶、RUBP羧化酶活性明显升高,且叶绿素、生长素含量也有明显变化,说明该真菌蛋白对植物的生长有明显的促进作用。     

哺乳动物α-羟基丁酸脱氢酶的测定及临床意义

α-羟基丁酸脱氢酶（HBDH）是心肌酶谱中的一种酶，在哺乳动物体内普遍存在，主要分布于心肌红细胞、白细胞及肾脏等。HBDH活性升高常见于急性心肌梗塞、骨骼肌损伤、急性肝炎、白血病及恶性肿瘤等。可用紫外动力学法、速率法、酶学比色法、连续检测等方法来测定HBDH的活性。LDH／HBDH比值可以帮助诊断肝病或心脏病。HBDH活性测定在临床诊断中有重要意义，在某些临床诊断中HBDH、CK、CK-MB需联合测定，但就心肌受损相关疾病而言，没必要同时检测。由于酶基因表达的多样性，基因表达调控上的差异性，产生了各种动物酶结构的多样性，进行HBDH的分子遗传研究非常必要。