的微型双元应变计测量加工和植入<em>体内</em>胃肠收缩鼠害。
Summary
The in vivo measurement of smooth muscle contractions along the gastrointestinal tract of laboratory animals remains a powerful, though underutilized, technique. Flexible, dual element strain gages are not commercially available and require fabrication. This protocol describes the construction of reliable, inexpensive strain gages for acute or chronic implantation in rodents.
Abstract
Gastrointestinal dysfunction remains a major cause of morbidity and mortality. Indeed, gastrointestinal (GI) motility in health and disease remains an area of productive research with over 1,400 published animal studies in just the last 5 years. Numerous techniques have been developed for quantifying smooth muscle activity of the stomach, small intestine, and colon. In vitro and ex vivo techniques offer powerful tools for mechanistic studies of GI function, but outside the context of the integrated systems inherent to an intact organism. Typically, measuring in vivo smooth muscle contractions of the stomach has involved an anesthetized preparation coupled with the introduction of a surgically placed pressure sensor, a static pressure load such as a mildly inflated balloon or by distending the stomach with fluid under barostatically-controlled feedback. Yet many of these approaches present unique disadvantages regarding both the interpretation of results as well as applicability for in vivo use in conscious experimental animal models. The use of dual element strain gages that have been affixed to the serosal surface of the GI tract has offered numerous experimental advantages, which may continue to outweigh the disadvantages. Since these gages are not commercially available, this video presentation provides a detailed, step-by-step guide to the fabrication of the current design of these gages. The strain gage described in this protocol is a design for recording gastric motility in rats. This design has been modified for recording smooth muscle activity along the entire GI tract and requires only subtle variation in the overall fabrication. Representative data from the entire GI tract are included as well as discussion of analysis methods, data interpretation and presentation.
Introduction
在体内胃肠道（GI）在多个实验条件蠕动的记录仍然是一个强大的工具，了解必要的营养平衡的基本正常和病理生理过程的实验研究。传统上，无数的实验方法，用一些相似的临床实践1，已经采用直接量化的改变胃肠道的收缩率2-5，腔内压力6，7，或不可吸收标志物8的胃肠道转运，发现9或稳定同位素10-12。每种技术都有其独特的优点和缺点，这在文献中先前已经解决。例如，气囊测压的效用量化的压力变化受到质疑由于气囊材料的固有遵守而不可吸收的标记物胃肠恢复需要安乐死试验阴性特质l对于单个数据点。最近，一个微型动脉压导管的应用和验证有报道称，提供了在大鼠和小鼠3监测胃收缩的非手术方法。而一个orogastrically放置压力传感器有效地避免侵入性手术过程中消除了对胃肠功能混杂变量，这种方法只适用于麻醉制剂。此外，由于缺乏视觉引导不允许胃的特定区域内的换能器的相一致的位置。因此，本申请中限定为胃或结肠因为可视化，再加上相对较硬的传感器导线，十二指肠内或回肠不是一个选项。
同样，生物磁交流电biosusceptometry（ACB）技术已被证实为胃肠道收缩分析4。而ACB技术提供了一种非侵入性的APproach测定胃肠道收缩，ACB患有中，类似的限制，利用摄入磁检测介质中，没有允许在胃肠道的特定区域的精确记录。这一限制可以通过对磁性标记的手术植入来克服。尽管如此，ACB技术的必要条件是该动物被麻醉，进行数据收集。
Ultrasonomicrometry已经用于一些GI，以便采取尺寸小，空间的优势研究13，第14，和压电晶体发射器/接收器的时间的优点。胃平滑肌收缩波都没有的高频事件和发生在大约3的速率 – 5个周期/分钟。因此，声纳微测量的时间的优点可能是不必要的，以证明费用。此外，尽管线性运动被准确地测量与声纳微测量，限制已经提出关于准确胃肠数据解释可能导致植入晶体14的数量不足的。
基于Bass和同事2,15的原创设计该协议的可视化更充分地记载了一步一步的制造和试验应用缩影，双晶应变计是具有高灵敏度和灵活性，在整个胃肠记录平滑肌收缩道。应变计元件的尺寸适合于任何啮齿类动物的应用，因为灵敏度成品应变计和尺寸是最依赖于硅薄片封装的元件。这些应变片很容易适应的麻醉和自由活动的实验动物模型急性和慢性的应用程序，从而提供量化平滑肌收缩单一技术。
Protocol
Representative Results
Discussion
这里介绍的方法允许单个实验室制造灵敏微型应变计用于生物应用，包括但不限于，胃肠道蠕动在小的实验室动物。由于这些应变片的商业化生产已经停止，实验室研究胃肠功能仅限于可能不允许全方位的实验应用可用的其他技术。这个报告对先前所描述的技术15的更新和更详细的描述。文本和相应的视频专门解决方案，使我们的发展制造工艺的掌握和认识过程中常见的陷阱。
<p class="…Divulgazioni
The authors have nothing to disclose.
Acknowledgements
科研经费是通过研究所收到的神经疾病和中风（NS049177和NS087834）的。作者要感谢已故的保罗博士巴斯和他的同事对应变计的原设计的知识贡献;和卡罗尔Tollefsrud为应变片的制造和销售，直到生产在2010年和她的见地通信停止。
Materials
| Strain gage element | Micro-Measurements (Vishay Product Group) | EA-06-031-350 | Linear pattern, foil, stress analysis strain gage (2 required) www.vishaypg.com/micro-measurements/ or http://www.vishaypg.com/docs/11070/031ce.pdf |
| epoxy-phenolic adhesive | M-bond 610 | General purpose adhesive for bonding strain gage elements | http://www.vishaypg.com/docs/11024/wirecable.pdf |
| 3 conductor insulated wire | 336-FTE | Fine gage, flexible general purpose wire | http://www.vishaypg.com/docs/11024/wirecable.pdf |
| Flux and rosin solvent kit | FAR-2 M-Flux AR kit | Liquid solder flux | http://www.vishaypg.com/docs/11023/soldacce.pdf |
| Solder | 361A-20R-25 | Optimized and recommended for strain gage applications | http://www.vishaypg.com/docs/11023/soldacce.pdf |
| Gold socket connector | PlasticsOne | E363/0 | Socket contact for electrode pedestal http://www.plastics1.com/PCR/Catalog/Item.php?item=407 |
| Electrode pedestal | MS363 | Secure platform for wire contacts | http://www.plastics1.com/PCR/Catalog/Item.php?item=499 |
| 6-wire cable | 363 PLUG W/VINYL SL/6 | Pre-fabricated vinyl-coated cable (in customized lengths) with plug adaptor to match electrode pedestal and tinned solder lugs on terminal end | |
| Silicone rubber casting compound | EIS electrical products | Elan Tron E211 | Potting medium for gage/wire solder joints http://www.eis-inc.com |
| HOTweezers | Meisei Corporation | Model 4B | Wire insulation strippers http://www.impexron.us |
| Soldering station | Weller (Apex Tool Group) | WES 51 | High quality soldering equipment http://www.apexhandtools.com/weller/index.cfm |
| Available through http://www.eis-inc.com or http://www.amazon.com | |||
| Silicone sheet | Trelleborg Sealing Solutions Northborough-Life Sciences | Pharmelast 20-20 | Encapsulating strain gauge elements 10 B Forbes Road Northborough, MA 01532 (800) 634-2000 |
| Amplifier | Experimetria Ltd | AMP-01-SG | http://experimetria.com/Biological_amplifiers.php |
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