Quantitative structural analysis of athletic hearts of racing pigeons

为了阐明赛鸽运动心脏的定量形态学特征，对48只3个月~ 10岁的长距离飞行赛鸽（RP）与65只与RP （Columva livia domestica）同品种的野鸽（FP）进行了心脏形态学测量。RP组的心重/体重比FP组高15.3 ~ 16.8% （P<0.01）。虽然RP组和FP组在给定横切面上室间隔和左室壁的横截面积、肌细胞横截面积和以单位面积心肌毛细血管数计算的毛细血管密度没有差异，但RP组左室腔的尺寸和肌细胞长度均显著大于FP组（分别为29.7%和16.2-20.1%，P<0.001）。从这些结果来看，心肌细胞长度越大，RP的心脏重量与体重之比越高，左室腔尺寸增大，而间隔和左室壁面积没有相应增加。总之，本研究的结果表明，在RP中观察到的运动心脏可以被视为长距离跑步者在动态运动训练中发生的体积超负荷心脏的一种典型偏心肥大形式，并且RP中的大心脏具有遗传基础。

Morphometric measurements of the heart in 48 racing pigeons (RP) aged from 3 months to 10 years, a breed selected for long-distance flying, were compared with data from 65 feral pigeons (FP), the same breed as RP (Columva livia domestica), in order to clarify the quantitative morphologic features of athletic hearts of racing pigeons. Heart weight to body weight ratios were 15.3-16.8% higher in RP than in FP (P<0.01). Although there was no difference between RP and FP in cross-sectional area of the septal and left ventricular wall in a given transverse plane, myocyte cross-sectional area, and the capillary density calculated as number of capillaries per unit area of the myocardium, the dimensions of the left ventricular cavity and myocyte length were both significantly greater in RP (29.7% and 16.2-20.1%, respectively ; P<0.001). From these findings, the greater myocyte length contributed the higher heart weight to body weight ratio of RP and to the enlargement of the dimensions of the left ventricular cavity without a proportionate increase in the septal and left ventricular wall area. In conclusion, the results of the present study suggest that athletic hearts observed in RP can be viewed as a form of the eccentric hypertrophy typical of volume-overloaded hearts that occurs with dynamic exercise training in long-distance runners, ant that large hearts in RP has a genetic basis.