运动性和高血压性肥大心脏心肌肌膜乳酸转运特征比较

ALTERATION OF LACTATE TRANSPORT BY CARDIAC SARCOLEMMAL VESICLES BETWEEN PHYSIOLOGICAL AND PATHOLOGICAL HYPERTROPHIC HEART

目的：探讨运动性和高血压性心肌肥大重塑时细胞表型代谢变化特征。方法：采用Ｌ１４Ｃ乳酸盐测定运动Ｗｉｓｔａｒ大鼠、自发性高血压大鼠（ｓｐｏｎｔａｎｅｏｕｓｌｙｈｙｐｅｒｔｅｎｓｉｖｅｒａｔｓ，ＳＨＲ）、运动ＳＨＲ和对照ＷｉｓｔａｒＫｙｏｔｏ（ＷＫＹ）大鼠的心肌肌膜囊泡（ｓａｒｃｏｌｅｍｍａｌｖｅｓｉｃｌｅ，ＳＬＶ）单羧酸盐乳酸转运载体变化。结果：Ｗｉｓｔａｒ大鼠经每日２ｈ的１０周游泳运动后，心系数比对照ＷＫＹ大鼠提高２９％，ＳＬＶ乳酸最大转运速率（ｌａｃｔａｔｅｔｒａｎｓｐｏｒｔｍａｘｉｍａｌｖｅｌｏｃｉｔｙ，Ｖｍａｘ）和米氏常数（Ｍｉｃｈａｅｌｉｓｃｏｎｓｔａｎｔ，Ｋｍ）分别提高１５％和４８％（Ｐ＜０．０１）。ＳＨＲ心系数比对照ＷＫＹ大鼠提高６１％，心肌Ｖｍａｘ和Ｋｍ值分别降低１９％和３０％（Ｐ＜０．０１）。ＳＨＲ经每日１～２ｈ的１０周游泳运动后，与未游泳ＳＨＲ相比，心系数变化无统计意义（Ｐ＞０．０５），但血压明显降低，Ｖｍａｘ提高５１％，Ｋｍ降低２８％（Ｐ＜０．０５）。结论：运动性和高血压性心肌肥大重塑时细胞表型在ＳＬＶ乳酸转运载体特征变化不同，前者ＳＬＶ乳酸转运能力提高，后者则降低。同时，运动还可明?

Aim and Methods: To investigate the different myocardial phenotype of physiological and pathological hypertrophic heart in metabolism, lactate transport by cardiac sarcolemmal vesicles (SLV) was studied by the L 14 C lactate uptake methods.Results: After Wistar rats subjected to a 12 weeks swimming program, their heart/body weight, maximal velocity of lactate transport by SLV(Vamx) and Michaelis constant(Km) increased by 29%, 15% and 48% respectively than that in sedentary Wistar Kyoto (WKY) rats( P <0. 01).Sedentary SHR heart/body weight was 61% higher, Vmax and Km were 19% and 30% lower than that in sedentary WKY rats respectively( P <0. 01). SHR following 10 weeks swimming increased Vmax by 51%( P <0. 01) and decreased by Km 28%( P <0. 05), but their heart/body weight were unchanged, compared with sedentary SHR( P >0. 05). Conclution:The finding suggested that the kinetic properties of lactate transport by cardiac SLV were different in myocardial phenotypes between physiological and pathological hypertrophic heart. The results also showed that exercise may enhance the ability of lactate transport by SLV of hypertensive hypertrophic haert.