Department of Zoology, University of British Columbia, Vancouver, BC, Canada V6T 1Z4.
Department of Integrative Biology, University of Guelph, Guelph, ON, Canada N1G 2W1.
Respir Physiol Neurobiol. 2014 Feb 1;192:118-27. doi: 10.1016/j.resp.2013.12.013. Epub 2013 Dec 27.
The aim of this study was to determine whether time domains exist in the hypoxic ventilatory (HVR) and cardiac responses (HCR) of bowfin (Amia calva), a facultative air breather, exposed to sustained hypoxia (SH) (26mmHg at 8°C or 45mmHg at 22°C). It was hypothesized that time domains would be evident in the HVR and HCR of bowfin when denied access to air during SH, as have been reported in mammals. It was also hypothesized that they would not be present in bowfin with access to air during SH because their oxygen supply should not be limited due to air breathing. Bowfin without access to air during SH exhibited time domains of the HVR and some time domains of the HCR. As hypothesized, bowfin with access to air did not exhibit time dependent changes in the gill breathing, air breathing, or cardiac responses to SH. The extent to which these reflect homologous processes to those underlying time domains in mammals remains to be determined.
本研究旨在确定在缺氧通气（HVR）和心脏反应（HCR）中是否存在时间域，以评估选择性空气呼吸的弓鳍鱼（Amia calva）在持续缺氧（SH）（8°C 时为 26mmHg，22°C 时为 45mmHg）下的情况。假设在 SH 期间剥夺弓鳍鱼接触空气的机会时，会在其 HVR 和 HCR 中出现时间域，这与哺乳动物的情况相似。还假设，当弓鳍鱼在 SH 期间可以接触空气时，它们不会出现时间域，因为它们的氧气供应不应因空气呼吸而受到限制。在 SH 期间无法接触空气的弓鳍鱼表现出 HVR 的时间域和 HCR 的一些时间域。如假设的那样，有空气接触的弓鳍鱼在 SH 时的鳃呼吸、空气呼吸或心脏反应中没有表现出时间依赖性变化。这些变化在多大程度上反映了与哺乳动物中时间域相关的同源过程仍有待确定。
