Tucker D C, Gist R
Circ Res. 1986 Nov;59(5):534-44. doi: 10.1161/01.res.59.5.534.
The influence of sympathetic innervation on the growth and intrinsic rate of beating established by fetal rat heart was studied by culturing fetal atrial tissue in sympathetically innervated and denervated anterior eye chambers of adult Sprague-Dawley rats. One anterior eye chamber in each host rat was sympathetically denervated by removing the ipsilateral superior cervical ganglion. In oculo, atrial grafts were vascularized by blood vessels sprouting from the iris and innervated by sympathetic and parasympathetic fibers from the ground plexus of the iris. Innervation was assessed by light-activated efferent nerve stimulation to the grafts that changed their rates of beating. The norepinephrine contents of 16 atria cultured for 2.5 months in sympathetically innervated and denervated eye chambers were 5.7 +/- 1.1 ng/implant vs. 0.2 +/- 0.07 ng/implant (mean +/- SEM), indicating permanent sympathetic denervation of the anterior eye chamber and the implanted atria. By 8 weeks in oculo, atria maturing in sympathetically innervated anterior eye chambers were 86% larger than those in denervated eye chambers (2.22 +/- 0.29 vs. 1.19 +/- 0.13 mm2); the weight of innervated transplants was over 3 times that of noninnervated grafts (2.35 +/- 0.75 vs. 0.76 +/- 0.21 mg). After implanted atria had ceased growing rapidly (2.5 months in oculo), bipolar electrodes were implanted adjacent to the cornea to record impulses from atrial grafts while host rats were unanesthetized. The dark-adapted baseline heart rates of sympathetically innervated and noninnervated atria were virtually identical (289 vs. 290 bpm). Graft intrinsic heart rate was estimated by combined beta-adrenergic and muscarinic receptor blockade with atenolol (1.0 mg/kg) and methylatropine (10 micrograms/kg). Sympathetically innervated transplants had lower intrinsic heart rates than noninnervated atria (134 +/- 25 vs. 213 +/- 12 bpm). These data suggest that sympathetic innervation of the developing heart influences both growth and intrinsic rate of beating.
通过将胎鼠心房组织培养于成年Sprague-Dawley大鼠经交感神经支配和去神经支配的前房内，研究交感神经支配对胎鼠心脏建立的生长及固有搏动率的影响。每只宿主大鼠的一个前房通过切除同侧颈上神经节进行去交感神经支配。在眼内，心房移植物由虹膜长出的血管供血，并由虹膜基质丛的交感和副交感纤维支配。通过对移植物进行光激活传出神经刺激来评估神经支配情况，这种刺激会改变移植物的搏动率。在交感神经支配和去神经支配的眼房内培养2.5个月的16个心房的去甲肾上腺素含量分别为5.7±1.1 ng/移植物和0.2±0.07 ng/移植物（平均值±标准误），表明前房及植入心房永久性去交感神经支配。眼内植入8周后，在交感神经支配的前房内成熟的心房比去神经支配眼房内的心房大86%（2.22±0.29对1.19±0.13平方毫米）；有神经支配的移植物重量是非神经支配移植物的3倍多（2.35±0.75对0.76±0.21毫克）。植入的心房停止快速生长后（眼内植入2.5个月），在宿主大鼠未麻醉的情况下，将双极电极植入角膜附近以记录心房移植物的冲动。交感神经支配和非神经支配心房的暗适应基础心率几乎相同（289对290次/分钟）。通过用阿替洛尔（1.0毫克/千克）和甲基阿托品（10微克/千克）联合阻断β-肾上腺素能和毒蕈碱受体来估计移植物的固有心率。交感神经支配的移植物的固有心率低于非神经支配的心房（134±25对213±12次/分钟）。这些数据表明，发育中心脏的交感神经支配会影响生长和固有搏动率。
