ESTROGEN EFFECTS ON CARDIOVASCULAR RESPONSE TO EXERCISE

描述(申请人的摘要)：静态和适度的动态锻炼是 已知可提高心率、心肌收缩能力、动脉血 压力、呼吸和肌肉交感神经放电。这些影响， 它们被认为可以增加新陈代谢活性的氧气的输送 女性的肌肉组织(即运动肌肉)似乎比男性少。 这种差异通常归因于雌激素对神经元的影响。 功能。因此，本申请中提出的实验的目的是 确定雌激素对“中枢指令”和肌肉的影响 反射，负责唤醒自主神经的两种神经机制 对运动的反应。拟议的研究将在去大脑中进行 未麻醉的雌性和雄性猫，它们要么被切除卵巢，要么被切除 分别于实验前2~4周去势。在这 准备，两种神经机制，中枢指令和肌肉反射， 可以在不受麻醉影响的情况下单独进行研究。其效果 雌激素(即17-β-雌二醇)对中枢指令的锻炼意志 在猫被维库溴铵麻痹时进行研究，并将被 下丘脑和中脑的电刺激和化学刺激 运动区。运动神经元对激动者和拮抗者后肢的放电 肌肉将被记录下来。激发中央指挥权的标准是 做一个“虚构的运动”。同样，雌激素对肌肉反射的影响 将被研究，但猫不会瘫痪。肌肉反射将是 在后肢肌肉自由灌流时和在他们 缺血症。雌激素对两种细胞的影响的剂量-反应关系 心血管和呼吸系统对中枢指令和肌肉的反应 条件反射将被确定。此外，研究还将扩展到雌激素。 将定时释药微丸植入去势的公猫体内进行预处理 摘除卵巢的女性。此外，微量注射卡介苗的效果 17β-雌二醇会进入下丘脑和中脑运动区 被确定是因为初步数据表明中央命令，但不是 肌肉反射，负责雌激素诱导的 运动引起的心血管和呼吸系统反应。

DESCRIPTION (Applicant's abstract): Static and moderate dynamic exercise are known to increase heart rate, myocardial contractility, arterial blood pressure, breathing and muscle sympathetic nerve discharge. These effects, which are believed to increase the delivery of oxygen to metabolically active tissues (i.e., the exercising muscles), appear to be less in women than in men. This difference is often attributed to the effect of estrogen on neuronal function. Consequently, the aim of the experiments proposed in this application is to identify the effect of estrogen on "central command" and the muscle reflex, the two neural mechanisms responsible for evoking the autonomic responses to exercise. The proposed studies will be done in decerebrate unanesthetized female and male cats, which have been either ovariectomized or castrated, respectively two to four weeks prior to the experiment. In this preparation, the two neural mechanisms, central command and the muscle reflex, can be investigated separately without the influence of anesthesia. The effect of estrogen (i.e., 17-beta-estradiol) on the central command to exercise will be studied while the cats are paralyzed with vecuronium, and will be evoked by both electrical and chemical stimulation of the hypothalamic and mesencephalic locomotor regions. Motoneuron discharge to agonist and antagonist hindlimb muscles will be recorded. The criterion for elicitation of central command will be "fictive locomotion." Likewise, the effect of estrogen on the muscle reflex will be studied, but the cats will not be paralyzed. The muscle reflex will be evoked both while the hindlimb muscles are freely perfused and while they are ischemic. Dose response relationships for the effect of estrogen on both the cardiovascular and respiratory responses to central command and the muscle reflex will be determined. Moreover, studies will be extended to estrogen pretreatment with timed release pellets implanted into castrated male cats and ovariectomized females. In addition, the effect of microinjections of 17beta-estradiol into the hypothalamic and mesencephalic locomotor regions will be determined because preliminary data suggest that central command, but not the muscle reflex, is responsible for the estrogen-induced attenuation of the cardiovascular and ventilatory responses to exercise.