Kirby R F, McCarty R
J Auton Nerv Syst. 1987 Apr;19(1):67-75. doi: 10.1016/0165-1838(87)90146-9.
The development of functional sympathetic innervation to the heart and adrenal medulla was examined in Long-Evans and Sprague-Dawley rats during the preweanling period. Insulin-induced hypoglycemia was used to produce a centrally mediated activation of the sympathetic nervous system and the induction of ornithine decarboxylase activity in the heart and the depletion of adrenal epinephrine were used as indices of sympathetically mediated responses in these target organs. First, dose by time response curves were performed in 11-13 day old Sprague-Dawley pups to establish an insulin dose which would simultaneously produce stimulation of cardiac ornithine decarboxylase activity and depletion of adrenal medullary epinephrine at an appropriate time post-injection. This dose of insulin was then administered to pups of different postnatal ages to determine the onset of functional sympathetic innervation to these target organs. Significant increases in heart ornithine decarboxylase activity were seen by two postnatal days of age in both rat strains examined. In contrast, adrenal epinephrine depletions were not found until 8-12 postnatal days of age. These results indicate that functional sympathetic neurotransmission to the heart is present in the first few days after birth, and this precedes the onset of sympathetic control of adrenal epinephrine release, which matures near the end of the first postnatal week in laboratory rats.
在断奶前阶段，对长 Evans 大鼠和斯普拉格 - 道利大鼠心脏和肾上腺髓质功能性交感神经支配的发育进行了研究。胰岛素诱导的低血糖被用于引发交感神经系统的中枢介导激活，心脏中鸟氨酸脱羧酶活性的诱导以及肾上腺肾上腺素的消耗被用作这些靶器官中交感神经介导反应的指标。首先，对 11 - 13 日龄的斯普拉格 - 道利幼崽进行剂量 - 时间反应曲线实验，以确定一种胰岛素剂量，该剂量能在注射后适当时间同时刺激心脏鸟氨酸脱羧酶活性并消耗肾上腺髓质肾上腺素。然后将此剂量的胰岛素给予不同出生后年龄的幼崽，以确定这些靶器官功能性交感神经支配的起始时间。在所检查的两种大鼠品系中，出生后两天龄时心脏鸟氨酸脱羧酶活性就出现了显著增加。相比之下，直到出生后 8 - 12 天龄才发现肾上腺肾上腺素的消耗。这些结果表明，出生后的头几天心脏就存在功能性交感神经传递，且这先于肾上腺肾上腺素释放的交感神经控制的起始，在实验室大鼠中，这种控制在出生后第一周接近尾声时成熟。
