Table 2.

Arterial blood gases, pH and mean arterial pressure (MAP) recorded in anesthetized rats during phrenic recording experiments

Parameter	Group	Baseline	Hypoxia
PaCO2 (mmHg)	Control	40±l	39±1
	2 weeks	37±1	a33±l
	4 weeks	36±1	a32±2
	8 weeks	37±1	b37±l
	12 weeks	36±2	34±2
PaO2 (mmHg)	Control	116±8	31±1
	2 weeks	a139±9	34±1
	4 weeks	122±9	31±2
	8 weeks	122±5	33±1
	12 weeks	125±6	33±1
pH	Control	7.32±0.01	7.32±0.01
	2 weeks	7.39±0.01	7.38±0.02
	4 weeks	7.35±0.01	7.35±0.01
	8 weeks	7.39±0.02	7.39±0.02
	12 weeks	7.41 ±0.01	a7.42±0.02
MAP (mmHg)	Control	129±6	99±10
	2 weeks	102±10	82±12
	4 weeks	101±7	c49±8
	8 weeks	110±4	89±6
	12 weeks	103±5	77±7

^aDifferent than corresponding value in the control group.

^bDifferent than corresponding value in 4-week post-C2HS

^cDifferent than all other groups.