Differences in cardiovascular responses to exercise between children with hypertensive parents and children with normotensive parents.

本研究调查了高血压儿童和正常父母的儿童在静态和动态运动时的心血管反应是否不同。实验1中，20名父母均为高血压的健康女性（h组）和20名父母均为高血压的年龄匹配的正常女性（n组）均进行2分钟的持续静态膝关节伸展，强度为最大自愿收缩（MVC）的30%。H-组和n -组在体大小、体脂、静息动脉平均血压（MAP）、心率（HR）、心输出量（CO）和总外周阻力（TPR）方面均无差异。两组在静态运动中MAP的增加也是相同的。而MAP的组成因子（即CO和TPR）存在明显差异。h组运动时CO显著低于n组，TPR显著高于n组。因此，h组MAP的升高是由TPR升高引起的，n组MAP的升高是由co升高引起的。静态运动时前臂血流量和前臂皮肤血流量测量结果表明，两组骨骼肌血管床和皮肤组织对运动的反应相同。因此，h组TPR升高是由除骨骼肌和皮肤组织外的血管床血管收缩增加引起的，这些血管床可能是内脏和肾床。实验II中，年龄、体型、体脂和静息MAP相同的H组和n组分别为21名女性和18名女性。两组都进行了20分钟的自行车运动，强度每5分钟增加一次，从最大运动的20%、40%、60%到80% （Loadmax）。在60%和80%负荷最大时，两组的心血管反应不同，尽管两组的耗氧量相同。MAP在h组显著高于n组。高强度时，h组MAP升高也与TPR升高有关，可能是由于脾和肾血管床的血管收缩更大。exp I和exp II的结果表明，h组在静态和动态运动时的心血管反应与n组不同，而h组的受试者现在是健康且血压正常的。少

The present study investigated if cardiovascular responses during static and dynamic exercises might be different between children with hypertensive parents and children with normotensive parents. Twenty healthy females whose parents had been in essential hypertension (H-group) and 20 age-matched normotensive females whose parents were both normotensive (N-group) served as subjects in EXP I.Both groups performed a 2-min sustained static knee extension of which intensity was 30 % of maximal voluntary contraction (MVC). There was no difference between H- and N-groups in body size, body fat, resting arterial mean blood pressure (MAP) , heart rate (HR) , cardiac output (CO) and total peripheral resistance (TPR). Increases of MAP during static exercise in both groups were also identical. However, there were clear differences in component factors of MAP (i.e., CO and TPR). CO during exercise in H-group was significantly lower than that in N-group while TPR in H-group was significantly higher … More than that in N-group. Thus, the increased MAP in H-group was caused by the elevated TPR while that in N-group was induced by the elevated CO.Forearm blood flow and forearm skin blood flow measured during static exercise indicated that vascular beds in skeletal muscles and cutaneous tissues showed identical responses to exercise in both groups. Therefore, the increased TPR in H-group was induced by increased vasoconstriction in vascular beds except for skeletal muscles and cutaneous tissues, which were probably splanchinic and renal beds. In EXP II,different twenty-one females and 18 females respectively served as subjects for H- and N-groups whose age, body size, body fat and resting MAP were identical. Both groups performed a 20-min bicycling exercise of which intensity increased every 5 min. from 20%, 40%, 60% to 80% of maximal exercise (Loadmax). During 60% and 80% Loadmax cardiovascular responses were different between two groups although oxygen consumption was identical in both groups. MAP in H-group increased significantly greater than that in N-group. The increased MAP in H-group during higher intensities was also caused by increased TPR,probably due to greater vasoconstriction in splanchinic and renal vascular beds. These results from EXPs I and II suggest that the cardiovascular responses to both static and dynamic exercises in H-group are different from those in N-group while the subjects in H-group are now healthy and normotensive. Less