面神经核背内侧区微量注射17-β雌二醇对颏舌肌和膈肌功能的影响

Effects of microinjection of 17-βestrogen into dorsal medial area of nucleus facialis on the activities of genioglossal muscle and phrenic muscle in rabbits

目的:探讨面神经核背内侧区微量注射17-β雌二醇(17-βestroge,E2)对颏舌肌和膈肌功能的影响。方法:选用21只健康成年家兔,随机分为实验组16只和对照组5只给予200mg/L氨基甲酸乙酯静脉麻醉,切断双侧迷走神经,建立动物窒息模型,面神经核背内侧区(dorsalmedialareaofnucleusfacialis,dMNF)微量注射0.1nmol/LE21μL,引导颏舌肌和膈肌肌电活动,观察注药前后肌电变化。结果:dMNF微量注射E2后,引起动物颏舌肌和膈肌肌电窒息增幅反应明显加强,注药10min作用最明显。与注药前相比,颏舌肌和膈肌肌电积分增幅峰值分别增加(38.76±8.17)%和(28.67±6.81)%(t=4.74,4.21,P<0.01),增幅潜伏期缩短(4.28±1.12)s和(3.98±0.73)s(t=3.82,5.45,P<0.01),增幅恢复时间延长(28.67±6.07)和(20.84±4.80)s(t=4.28,4.34,P<0.01)。结论:E2通过作用于dMNF神经元加强颏舌肌和膈肌肌电活动,产生减小上呼吸道阻力和调节呼吸的作用。

AIM: To observe the effects of the microinjection of 17 βestrogen(E2) into dorsal medial area of nucleus facialis(dMNF) on the myoelectric activities of genioglossal muscle(GG) and phrenic muscle(Phr). METHODS:Twenty one healthy adult rabbits were selected and randomized into experimental group(n=16) and control group(n=5).Bilateral vagus nerves were amputated in the rabbits under the anesthesia of 200 mg/L urethane via vein to establish the animal models of apnea.The microinjection of 1 μL 0.1 nmol/L 17 βE2 into dMNF was used to induce the activity of GG and Phr so as to observe the myoelectric changes before and after treatment. RESULTS:Amplitude augmenting response to apneaof GG and Phr myoelectric activity was increased.Ten minutes after microinjection,the peak amplitudes of GG and Phr myoelectric integration were increased by(38.76±8.17)%and(28.67±6.81)%(t=4.74, 4.21,P< 0.01),the latencies were shortened to(4.28±1.12)s and(3.98±0.73)s respectively(t=3.82, 5.45,P< 0.01),and the recovery time of amplitude was prolonged to(28.67±6.07)s and(20.84±4.80)s respectively(t=4.28, 4.34,P< 0.01). CONCLUSION:E2 can improve the myoelectric activities of GG and Phr with excitation of dMNF,and markedly decrease the resistance of upper airway and modulation of respiration.