测量中晚期胚胎和新生小鼠左心室压力
Summary
测量左室压力在胚胎和新生小鼠（LV）的描述。压力测量插入到LV连接到一个充满液体的传感器，超声引导下针。必须小心维持正常的心脏功能，在实验协议。
Abstract
血压显着增加脊椎动物在胚胎和出生后的发展。在小鼠，血流量首先是围绕胚胎一天（五）8.5 1检测。收缩期左心室（LV）压力是E9.5在2毫米汞柱和11毫米汞柱在E14.5 2。在这些中期萌芽阶段，LV是清晰可见，通过创血压测量胸壁肋骨和皮肤，因为没有得到充分的开发。在E14.5和出生（约E21号）的成像方法必须使用查看LV。出生后，平均动脉压力增大30 – 35 3 – 70毫米汞柱从产后天（P）2。超越P20的，可以测量血压与固态导管（即米勒或Scisense）。 P20的之前，这些导管有太大发展小鼠动脉和动脉血压测量必须用自定义拉塑料导管连接到充液压力传感器或玻璃micropipettes ATT痛伺服空压力传感器4。
我们最近的工作表明，血压增幅最大的中后期早在产后5-7小鼠胚胎发生。这种血压的大量增加，可能会影响发展的动脉平滑肌细胞（SMC）的表型和触发重要的机械传导事件。在人类疾病，地方发展动脉的性能是在细胞外基质蛋白（即马凡氏的综合症8和主动脉瓣上狭窄9）的缺陷损害血压，在此期间迅速变化可能有助于疾病的表型和严重程度通过在机械传导的改变信号。因此，重要的是要能够测量血压的变化，人类疾病的小鼠模型中后期胚胎和新生儿时期。
我们描述了在后期测量左室压力的方法胚胎（E18）和产后早期（小 – 20）小鼠。超声引导下，一个充满液体的压力传感器连接到一个针插入的LV。护理是采取维持正常的心脏功能，尤其是在实验协议的小鼠胚胎。有代表性的数据提出并讨论了该协议的限制。
Protocol
Discussion
这里介绍的协议提供了一个LV的压力，在后期的胚胎和新生儿早期小鼠的测量方法。该协议的主要限制是压力系统的时间分辨率。压力信号衰减，因为它从LV旅行通过针传感器，不仅意味着可以记录压力值。最小的阻尼可以通过使用尽可能最大的针，但针必须在LV流明，适合不同年龄的小鼠。因为舒张压可近似为零，LV因此动脉收缩压，可以计算平均LV压力测量。虽然额外动脉变量将是理想的（…
Disclosures
The authors have nothing to disclose.
Acknowledgements
资助，这项工作的一部分，由NIH资助HL087653和HL105314。在博士罗伯特Mecham的实验室在华盛顿大学医学院的一些方法。
Materials
| Name of the reagent/equipment | Company | Catalogue number | Comments |
| High resolution ultrasound system | Visualsonics | Vevo 770 | Or other appropriate ultrasound system |
| High frequency ultrasound probes | Visualsonics | 708 and 707B | |
| Imaging platform and injection arm | Visualsonics | Imaging Station 2 | With ECG and temperature feedback control of platform |
| Pressure transducer | AD Instruments | MLT 844 | |
| Bridge amplifier | AD Instruments | ML221 | |
| Data acquisition system | AD Instruments | ML866 | |
| Data recording software | AD Instruments | LabChart | |
| Ring stand and clamp | Various suppliers | To hold pressure transducer during measurements | |
| 3-way stopcocks with luer connections, male lock | Cole Parmer | 30600-02 | |
| 1/16″ ID Tygon Tubing | Cole Parmer | 06408 | |
| Male and female luers w/ 1/16″ hose barb | Cole Parmer | 45510-50 45510-00 | |
| 24″ tubing with male and female luer at each end | Cole Parmer | 30600-60 | |
| 3 and 10 mL syringes | BD Biosciences | ||
| 30 and 25G needles | BD Biosciences | 1.5 inches in length | |
| Big Ben manometer | Riester | 1456-100 | |
| Saline | Various suppliers | ||
| Heparin | Various suppliers | ||
| Ultrasound gel | Parker | Aquasonic 100 | |
| Hair remover lotion | Nair |
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