The Regulation Index: A New Method for Assessing the Relationship between Oxygen Consumption and Environmental Oxygen

作者：Mueller Casey A^*; Seymour Roger S

来源：Physiological and Biochemical Zoology, 2011, 84(5): 522-532.

DOI：10.1086/661953

Critical oxygen pressure (P(C)) is used in respiratory physiology to measure the response to hypoxia. P(C) defines the partial pressure of oxygen (Po(2)) at which an oxygen regulator switches to a conformer. However, not all animals show such clear patterns in oxygen consumption rate ((M) over dotO(2)), and there are many meth. ods for determining P(C). This study assesses two methods that determine regulatory ability and four that calculate P(C). A new method, the regulation index (RI), assigns to an animal a relative measure of regulatory ability by calculating the area under the (M) over dotO(2) versus Po(2) curve that is greater than a linear trend. The six methods are applied to developmental (M) over dotO(2) data of two amphibians, Pseudophryne bibronii and Crinia georgiana. The four methods used to determine P(C) produced similar results but failed to identify the increase in regulation on hatching in C. georgiana or the greater regulation in larval C. georgiana compared with P. bibronii. Of the two methods that evaluated regulation, only the RI satisfactorily represented the entire range of Po(2). The RI is advantageous because it has clearly defined limits and does not constrain data to fit any single pattern.

• 出版日期2011-10