Hermanussen M, De Los Angeles Rol De Lama M, Burmeister J, Fernandez-Tresguerres J A
Department of Physiology Medical School, University Complutense, Madrid, Espania.
Physiol Behav. 1995 Aug;58(2):347-52. doi: 10.1016/0031-9384(95)00062-n.
A novel, noninvasive technique for accurate measurements is presented which determines the distance between knee and heel of the rear lower leg in the conscious rat (mikro-knemometry). Each measurement consists of initially six, later four subsequent and independent estimations of this distance. During a 14-day training study, the mean standard deviation (technical error) of five (six minus the first estimation) decreased from 196 microns to 101 microns. Measurements at exact 24-h intervals revealed nonlinear increments of rat lower leg growth, with marked infradian variation once every four to six days, similar to "mini growth spurts", described in rabbit and human growth. There was also a significant circadian periodicity of leg length increment (p < 0.01), with a minimum leg increment (after midnight dip) between 2400 h and 0300 h (mean: 4.8% (SEM 2.3%) of the total 24-h increment, p < 0.01), and a maximum increment (early morning spurt) between 0600 h and 0900 h (mean: 34.9% (SEM 2.5%) of the total 24-h increment, p < 0.001). Thus, the technique of mikro-knemometry seems to be a useful tool for the investigation of longitudinal growth in laboratory rats, and may replace conventional techniques of growth measurements such as measuring body weight, nose-tail, or tail length.
本文介绍了一种用于精确测量的新型非侵入性技术，该技术可测定清醒大鼠后小腿膝盖与足跟之间的距离（微小腿测量法）。每次测量最初包括对该距离的六次估计，之后为四次后续独立估计。在一项为期14天的训练研究中，五次测量（六次测量减去第一次测量）的平均标准差（技术误差）从196微米降至101微米。每隔24小时进行的测量显示，大鼠小腿生长呈非线性增加，每四至六天有明显的亚日变化，类似于在兔子和人类生长中描述的“微型生长突增”。小腿长度增加也存在显著的昼夜周期性（p<0.01），在24:00至03:00之间小腿增加量最小（午夜后下降）（平均：占24小时总增加量的4.8%（标准误2.3%），p<0.01），在06:00至09:00之间增加量最大（清晨突增）（平均：占24小时总增加量的34.9%（标准误2.5%），p<0.001）。因此，微小腿测量法似乎是研究实验大鼠纵向生长的有用工具，并且可能取代诸如测量体重、鼻尾或尾长等传统生长测量技术。
