Schlenker Evelyn H, Shi Yijiang, Wipf Joni, Martin Douglas S, Kost Curtis K
Basic Biomedical Sciences, Univ. of South Dakota School of Medicine, Vermillion, SD 57069, USA.
J Appl Physiol (1985). 2004 Oct;97(4):1387-94. doi: 10.1152/japplphysiol.00280.2004. Epub 2004 Jun 11.
We hypothesized that, in male rats, 10% fructose in drinking water would depress ventilatory responsiveness to acute hypoxia (10% O2 in N2) and hypercapnia (5% CO2 in O2) that would be depressed further by exposure to intermittent hypoxia. Minute ventilation (Ve) in air and in response to acute hypoxia and hypercapnia was evaluated in 10 rats before fructose feeding (FF), during 6 wk of FF, and after FF was removed for 2 wk. During FF, five rats were exposed to intermittent air and five to intermittent hypoxia for 13 days. Six rats given tap water acted as control and were exposed to intermittent air and subsequently intermittent hypoxia. In FF rats, plasma insulin levels increased threefold in the rats exposed to intermittent hypoxia and during washout returned to levels observed in rats exposed to intermittent air. During FF, ventilatory responsiveness to acute hypoxia was depressed because of decreased tidal volume (Vt) responsiveness. During washout, Ve decreased as a result of decreased Vt and frequency of breathing, and the ventilatory responsiveness to hypoxia in intermittent hypoxia rats did not recover. In all rats, the ventilatory responses to hypercapnia were decreased during FF and recovered after washout because of an increased Vt responsiveness. In the control group, hypoxic responsiveness was not depressed after intermittent hypoxia and was augmented after washout. Thus FF attenuated the ventilatory responsiveness of conscious rats to hypoxia and hypercapnia. Intermittent hypoxia interacted with FF to increase insulin levels and depress ventilatory responses to acute hypoxia that remained depressed during washout.
我们假设，在雄性大鼠中，饮用水中10%的果糖会降低对急性低氧（氮气中10%氧气）和高碳酸血症（氧气中5%二氧化碳）的通气反应性，而间歇性低氧暴露会进一步降低这种反应性。在10只大鼠中，分别在喂食果糖前（FF）、FF持续6周期间以及停止FF 2周后，评估了它们在空气中以及对急性低氧和高碳酸血症的分钟通气量（Ve）。在FF期间，5只大鼠暴露于间歇性空气环境，5只暴露于间歇性低氧环境，持续13天。6只饮用自来水的大鼠作为对照，先暴露于间歇性空气环境，随后暴露于间歇性低氧环境。在FF大鼠中，暴露于间歇性低氧环境的大鼠血浆胰岛素水平增加了三倍，在洗脱期恢复到暴露于间歇性空气环境的大鼠所观察到的水平。在FF期间，由于潮气量（Vt）反应性降低，对急性低氧的通气反应性受到抑制。在洗脱期，由于Vt和呼吸频率降低，Ve下降，间歇性低氧大鼠对低氧的通气反应性未恢复。在所有大鼠中，FF期间对高碳酸血症的通气反应降低，洗脱期后由于Vt反应性增加而恢复。在对照组中，间歇性低氧后低氧反应性未降低，洗脱期后增强。因此，FF减弱了清醒大鼠对低氧和高碳酸血症的通气反应性。间歇性低氧与FF相互作用，增加胰岛素水平并降低对急性低氧的通气反应，在洗脱期这种反应仍受到抑制。
