Fig. 9.

Patterns of ventilatory acclimatization of hypoxia (VAH) observed in the literature for adult rats. (A) Patterns were characterized based on whether normoxic ventilation (NX), hypoxic ventilation (HX), or the change in ventilation (HVR) differed between CH and Control groups; CH was considered to have had an effect if the difference between groups exceeded 10% (i.e., ratios greater than or equal to 1.1, or ratios less than or equal to 0.9). The three principal patterns included no change in the acute HVR (pattern 1), an augmented HVR (pattern 2), or a blunted HVR (pattern 3); pattern 3 was subdivided based on whether hypoxic ventilation was increased compared to chronically hypoxic rats (pattern 3A), unchanged (pattern 3B), or decreased (pattern 3C). (B) Relative frequency for patterns of VAH in adult rats based on the 25 published studies (including the present study) for which sufficient data were available (see Appendix B). (C) Data from panel B separated based on whether normobaric hypoxia (Normo; n= 9.25 studies) or hypobaric hypoxia (Hypo; n= 15.75 studies) was used for the CH exposure. Individual published studies were used as the unit of replication, so fractions of studies were counted where multiple relevant data sets were reported in the same study (see Methods section for details).