ESTROGEN EFFECTS ON CARDIOVASCULAR RESPONSE TO EXERCISE

描述（申请人摘要）：静态和适度的动态运动是 增加心率，心肌收缩力，动脉血 压力、呼吸和肌肉交感神经放电。这些影响， 这被认为增加了氧气的输送， 组织（即，运动肌肉），女性似乎比男性少。 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 是为了确定雌激素对“中央指挥”和肌肉的影响， 反射，这两种神经机制负责唤起自主神经 对锻炼的反应。拟定的研究将在去大脑中进行 未麻醉的雌性和雄性猫，其已经卵巢切除或 去势，分别在实验前2 - 4周。在这 准备，两个神经机制，中央命令和肌肉反射， 可以在不受麻醉影响的情况下单独进行研究。效果 雌激素（即，17-β-雌二醇）对中央指挥行使意志 当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和拮抗后肢的放电 肌肉将被记录。中央指挥部的诱导标准 是“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。肌肉反射会 诱发，而后肢肌肉自由灌注，而他们是 局部缺血雌激素对这两种作用的剂量反应关系 心血管和呼吸系统对中枢指令和肌肉的反应 反射将被确定。此外，研究将扩展到雌激素 用植入去势公猫体内的定时释放小丸进行预处理， 卵巢切除的雌性。此外，微量注射的效果 17 β-雌二醇进入下丘脑和中脑运动区， 因为初步数据表明，中央指挥部，但不是 肌肉反射，是负责雌激素诱导的衰减， 心血管和呼吸系统对运动的反应。

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.