Department of Physiology, Michigan State University College of Osteopathic Medicine , East Lansing, Michigan.
J Appl Physiol (1985). 2018 Jun 1;124(6):1471-1482. doi: 10.1152/japplphysiol.01104.2017. Epub 2018 Feb 22.
Spinal cord injury (SCI) resulting in tetraplegia is a devastating, life-changing insult causing paralysis and sensory impairment as well as distinct autonomic dysfunction that triggers compromised cardiovascular, bowel, bladder, and sexual activity. Life becomes a battle for independence as even routine bodily functions and the smallest activity of daily living become major challenges. Accordingly, there is a critical need for a chronic preclinical model of tetraplegia. This report addresses this critical need by comparing, for the first time, resting-, reflex-, and stress-induced cardiovascular, autonomic, and hormonal responses each week for 4 wk in 12 sham-operated intact rats and 12 rats with chronic, complete C spinal cord transection. Loss of supraspinal control to all sympathetic preganglionic neurons projecting to the heart and vasculature resulted in a profound bradycardia and hypotension, reduced cardiac sympathetic and parasympathetic tonus, reduced reflex- and stress-induced sympathetic responses, and reduced sympathetic support of blood pressure as well as enhanced reliance on angiotensin to maintain arterial blood pressure. Histological examination of the nucleus ambiguus and stellate ganglia supports the profound and distinct autonomic and cardiac deficits and reliance on angiotensin to maintain cardiovascular stability following chronic, complete cervical cord transection. NEW & NOTEWORTHY For the first time, resting-, reflex-, and stress-induced cardiovascular, autonomic, and hormonal responses were studied in rats with chronic, complete C cord transection. Loss of supraspinal control of all sympathetic preganglionic neurons reduced cardiac sympathetic and parasympathetic tonus, reflex and stress-induced sympathetic responses, and sympathetic support of blood pressure as well as enhanced reliance on angiotensin to maintain arterial blood pressure. Histological examination supports the distinct deficits associated with cervical cord injury.
脊髓损伤（SCI）导致四肢瘫痪是一种毁灭性的、改变生活的损伤，会导致瘫痪和感觉障碍，以及明显的自主功能障碍，从而引发心血管、肠道、膀胱和性功能受损。由于即使是日常的身体功能和最微小的日常生活活动也成为主要挑战，因此生活成为了一场争取独立的战斗。因此，非常需要一种慢性的四肢瘫痪临床前模型。本报告通过首次比较 12 只假手术完整大鼠和 12 只慢性完全 C 脊髓横切大鼠的静息、反射和应激诱导的心血管、自主和激素反应，满足了这一关键需求。结果表明，投射到心脏和血管的所有交感节前神经元的上位神经控制丧失导致了严重的心动过缓和低血压、心脏交感和副交感张力降低、反射和应激诱导的交感反应降低以及血压的交感支持降低，同时增强了对血管紧张素维持动脉血压的依赖。疑核和星状神经节的组织学检查支持在慢性完全颈髓横切后，存在严重和明显的自主和心脏缺陷，以及对血管紧张素维持心血管稳定性的依赖。
首次研究了慢性完全 C 脊髓横切大鼠的静息、反射和应激诱导的心血管、自主和激素反应。
上位神经对所有交感节前神经元的控制丧失降低了心脏交感和副交感张力、反射和应激诱导的交感反应以及血压的交感支持，同时增强了对血管紧张素维持动脉血压的依赖。
组织学检查支持与颈髓损伤相关的明显缺陷。
