. Author manuscript; available in PMC: 2015 May 14.

Published in final edited form as: Respir Physiol Neurobiol. 2013 Jul 23;189(1):136–143. doi: 10.1016/j.resp.2013.07.007

Table 1.

Arterial blood-gas chemistry and Alveolar-arterial gradients in tracheotomized rats

Parameter	Treatment	Sampling Periods
Parameter	Treatment	Pre	Morphine	Dose 1	Dose 2
pH	Vehicle	7.447 ± 0.006	7.332 ± 0.033^*	7.337 ± 0.032^*	7.330 ± 0.031^*
	L-cysteine	7.445 ± 0.004	7.328 ± 0.11^*	7.315 ± 0.008^*	7.332 ± 0.17^*
	L-SERee	7.440 ± 0.003	7.327 ± 0.018^*	7.306 ± 0.021^*	7.321 ± 0.019^*
pCO2	Vehicle	34.6 ± 0.5	47.0 ± 1.0^*	45.1 ± 2.0^*	47.3 ± 1.9^*
	L-cysteine	34.4 ± 0.5	47.5 ± 1.5^*	46.9 ± 1.8^*	47.1 ± 1.4^*
	L-SERee	34.0 ± 0.7	47.9 ± 1.2^*	47.6 ± 1.6^*	46.3 ± 0.7^*
pO2	Vehicle	92.3 ± 1.1	71.4 ± 2.4^*	71.7 ± 2.6^*	71.1 ± 2.3^*
	L-cysteine	92.1 ± 1.0	69.5 ± 0.8^*	69.3 ± 1.3^*	70.1 ± 0.3^*
	L-SERee	91.7 ± 0.06	70.8 ± 0.7^*	69.8 ± 2.9^*	68.7 ± 1.1^*
sO2	Vehicle	99.3 ± 0.07	85.4 ± 2.3^*	84.0 ± 4.1^*	83.6 ± 3.7^*
	L-cysteine	98.8 ± 0.7	83.2 ± 1.7^*	84.3 ± 2.0^*	83.3 ± 1.5^*
	L-SERee	98.8 ± 0.7	83.2 ± 1.7^*	84.3 ± 2.0^*	83.3 ± 1.5^*
A-a	Vehicle	14.2 ± 1.0	19.6 ± 3.1^*	21.6 ± 2.8^*	19.5 ± 2.8^*
	L-cysteine	14.6 ± 1.6	20.8 ± 1.9^*	21.8 ± 2.2^*	20.7 ± 2.1^*
	L-SERee	14.5 ± 1.0	19.1 ± 1.5^*	20.5 ± 2.2^*	23.2 ± 1.3^*

The data are presented as mean ± SEM. There were 5 rats in each group.

P < significant effect of morphine. A-a, Alveolar-arterial gradient. Note that neither L-cysteine nor L-serine ethylester (L-SERee) affected any of the morphine-induced responses (P >0.05 for all comparisons).