ORIGINS OF THE EXERCISE REFLEX

运动反射的起源

基本信息

批准号：
3448991
负责人：
CHARLES L STEBBINS
金额：
$ 4.8万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
1985
资助国家：
美国
起止时间：
1985-07-10 至 1988-06-30
项目状态：
已结题

项目摘要

The objective of this proposed research is to address specific deficiencies in our understanding of the chemical factors within contracting muscle that contribute to the reflex cardiovascular response to exercise. A better understanding of these factors may allow physicians to modify these responses where they may be harmful, for instance in patients with ischemic heart disease. The specific aims and methodologies are: 1) determination of the reflex potential of chemical stimuli released during muscular contraction. This will be accomplished by stimulating the cat's skeletal muscle with intra-arterial injections of each chemical to evoke a cardiovascular response. The reflex nature of the response will be confirmed by denervation of the gracilis. 2) Evaluation of the contribution of those chemical stimuli with reflex potential to the reflex cardiovascular response evoked by static muscular contraction. To evaluate the potential contribution of each chemical, the cardiovascular response to ventral root stimulated static contraction will be attenuated by inhibiting the production or action of the substance pharmacologically or by enhancing its degradation by infusing the appropriate enzyme responsible for catabolism. Alternatively, the degradation of a given chemical will be inhibited pharmacologically to demonstrate an augmented contraction-induced cardiovascular response. 3) Evaluation of the relationship between changes in interstitial PO2, PCO2 and pH to the onset and magnitude of the cardiovascular response to electrically stimulated contraction. To study this effect, skeletal muscle interstitial PO2, PCO2 and pH will be measured with mini-electrodes during contraction and contraction accompanied with ischemia. The time course and magnitude of changes in these variables will be compared to the onset and magnitude of the cardiovascular responses to contraction and contraction with ischemia. The cardiovascular response to pharmacological stimulation and hindlimb contraction will be evaluated by assessing changes in arterial blood pressure, heart rate and contractility. In some animals changes in preload, aortic flow and systemic vascular resistance also will be assessed.

这项研究的目的是解决具体的缺陷在我们对收缩肌肉中的化学因素的理解中有助于心血管对运动的反射反应。更好的了解这些因素可以让医生修改这些可能有害的反应，例如缺血患者心脏病。具体目标和方法是：1）确定肌肉运动过程中释放的化学刺激的反射电位收缩。这将通过刺激猫的骨骼来完成动脉内注射每种化学物质以激发肌肉心血管反应。响应的反射性质将是通过股薄肌去神经术证实。 2）评估那些具有反射潜力的化学刺激对反射的贡献静态肌肉收缩引起的心血管反应。评估每种化学物质的潜在贡献，心血管反应腹根刺激的静态收缩将通过抑制而减弱该物质的药理学产生或作用或通过增强通过注入适当的酶来降解它分解代谢。或者，给定化学品的降解将是药理学抑制以证明增强的收缩诱导心血管反应。 3）评估变化之间的关系间质 PO2、PCO2 和 pH 值对开始和程度的影响心血管对电刺激收缩的反应。学习通过这种效应，将测量骨骼肌间质 PO2、PCO2 和 pH 值在收缩期间和收缩期间带有微型电极缺血。这些变量的时间进程和变化幅度将与心血管反应的发生和程度进行比较收缩和缺血收缩。心血管反应药物刺激和后肢收缩将通过以下方式进行评估评估动脉血压、心率和收缩性。在一些动物中，前负荷、主动脉血流和还将评估全身血管阻力。