McConaghy F F, Hodgson D R, Rose R J, Hales J R
Equine Performance Laboratory, University of Sydney, NSW, Australia.
Equine Vet J Suppl. 1996 Jul(22):42-6. doi: 10.1111/j.2042-3306.1996.tb05030.x.
Radioactive microspheres were used to measure cardiac output and blood flow to most major tissues in 4 ponies at rest in thermoneutral (16 degrees C/60% RH) and mildly hot (41 degrees C/34% RH) environments. In response to heat stress there were increases in cardiac output (2-fold), respiratory frequency (5-fold), blood flow to the skin of the body (3-fold), and limbs (50%), respiratory muscles (2-fold) and the upper respiratory tract (3-fold). Ponies were able to maintain body temperature in the hot environment by increasing blood flow to the tissues involved in heat dissipation, while blood flow to all other tissues remained stable. This was achieved by increasing the cardiac output without need for reduction of blood flow to other tissues.
在热中性（16摄氏度/60%相对湿度）和轻度炎热（41摄氏度/34%相对湿度）环境中，对4匹处于休息状态的小马使用放射性微球来测量心输出量以及流向大多数主要组织的血流量。作为对热应激的反应，心输出量增加了两倍，呼吸频率增加了五倍，流向身体皮肤的血流量增加了三倍，四肢增加了50%，呼吸肌增加了两倍，上呼吸道增加了三倍。小马能够通过增加流向参与散热的组织的血流量来在炎热环境中维持体温，而流向所有其他组织的血流量保持稳定。这是通过增加心输出量实现的，而无需减少流向其他组织的血流量。
