Leon Lisa R, Walker Larry D, DuBose David A, Stephenson Lou A
U.S. Army Research Institute of Environmental Medicine, Thermal and Mountain Medicine Division, 42 Kansas Street, Natick, MA 01760-5007, USA.
Am J Physiol Regul Integr Comp Physiol. 2004 May;286(5):R967-74. doi: 10.1152/ajpregu.00380.2003. Epub 2004 Jan 15.
The implantation of a biotelemetry transmitter for core body temperature (T(c)) and motor activity (MA) measurements is hypothesized to have effects on growth and circadian rhythmicity depending on animal body-to-transmitter (B:T) size ratio. This study examined the impact of transmitter implantation (TM) on body weight, food intake (FI), water intake (WI), and circadian T(c) and MA rhythms in mice (23.8 +/- 0.04 g) and rats (311.5 +/- 5.1 g) receiving no treatment (NT), anesthesia, laparotomy (LAP), and TM. The B:T size ratio was 6:1 and 84:1 for mice and rats, respectively. In mice, body weight required 14 days to recover to presurgical levels and never attained the level of the other groups. FI recovered in 3 days, whereas WI never reached presurgical levels. Rat body weight did not decrease below presurgical levels. FI and WI recovered to presurgical levels in rats by day 2 postsurgery. Anesthesia decreased mouse body weight for 1 wk, but was without effect in rats. LAP significantly decreased body weight for 5 days in mice and 1 day in rats, showing a significant effect of the surgical procedure in the absence of TM in both species. Circadian T(c) and MA rhythms were evident within the first week in both species, indicating dissociation between circadian rhythmicity and recovery of growth variables. Cosinor analysis showed a TM effect on T(c) min, T(c) max, mesor, amplitude, and period of mice, whereas only the amplitude of the rhythm was affected in rats. These data indicate that a large B:T size ratio is associated with minimization of the adverse effects of surgical implantation. We recommend that B:T size ratio, recovery of presurgical body weight, and display of a robust circadian T(c) and MA rhythm be established before collection of biotelemetry data collection under an experimental paradigm.
据推测，植入用于测量核心体温（T(c)）和运动活动（MA）的生物遥测发射器会根据动物身体与发射器（B:T）的大小比例对生长和昼夜节律产生影响。本研究考察了发射器植入（TM）对未接受治疗（NT）、麻醉、剖腹术（LAP）和TM的小鼠（23.8±0.04克）和大鼠（311.5±5.1克）的体重、食物摄入量（FI）、水摄入量（WI）以及昼夜T(c)和MA节律的影响。小鼠和大鼠的B:T大小比例分别为6:1和84:1。在小鼠中，体重需要14天才能恢复到手术前水平，且从未达到其他组的水平。FI在3天内恢复，而WI从未达到手术前水平。大鼠体重未降至手术前水平以下。大鼠的FI和WI在术后第2天恢复到手术前水平。麻醉使小鼠体重下降了1周，但对大鼠没有影响。LAP使小鼠体重显著下降5天，使大鼠体重显著下降1天，表明在两个物种中，在没有TM的情况下，手术操作有显著影响。两个物种在第一周内昼夜T(c)和MA节律都很明显，表明昼夜节律与生长变量的恢复之间没有关联。余弦分析显示TM对小鼠的T(c)最小值、T(c)最大值、中值、振幅和周期有影响，而在大鼠中仅节律的振幅受到影响。这些数据表明，较大的B:T大小比例与手术植入的不良反应最小化相关。我们建议在实验范式下收集生物遥测数据之前，应确定B:T大小比例、手术前体重的恢复情况以及稳健的昼夜T(c)和MA节律的表现。
