. Author manuscript; available in PMC: 2009 Sep 1.

Published in final edited form as: Neurotoxicol Teratol. 2008 Mar 21;30(5):448–454. doi: 10.1016/j.ntt.2008.03.063

Table 4.

Ventilatory measurements of in utero opioid exposed neonatal guinea pigs during RA breathing

	Age	V_O₂ [ml^.min⁻¹^.100g⁻¹]	V_CO₂ [ml^.min⁻¹^.100g⁻¹]	V_I/V_O₂	V_I/V_CO₂	RER
Vehicle	3 days	3.5 ± 0.5^b	2.7 ± 0.2^b	30 ± 4	37 ± 3	0.82 ± 0.06
	7 days	3.3 ± 0.1^b	2.5 ± 0.1	25 ± 3	34 ± 4	0.75 ± 0.01
	14 days	2.5 ± 0.1	2.1 ± 0.1	27 ± 1	32 ± 1	0.86 ± 0.03

Methadone	3 days	4.2 ± 0.1^*^a ^b	3.0 ± 0.1^b	27 ± 6^{^^}	38 ± 9^{^^^}	0.75 ± 0.02^b
	7 days	3.3 ± 0.2^b	2.7 ± 0.1	22 ± 2	27 ± 2	0.81 ± 0.02
	14 days	2.7 ± 0.3	2.4 ± 0.1	25 ± 2	28 ± 2	0.92 ± 0.06

Morphine	3 days	4.4 ± 0.2^**^a ^b	3.3 ± 0.1^**^a ^b	51 ± 9^**^a ^b	68 ± 12^***^a ^b	0.74 ± 0.02^b
	7 days	3.3 ± 0.2^b	2.6 ± 0.1	28 ± 4	36 ± 5	0.78 ± 0.04^b
	14 days	2.3 ± 0.1	2.1 ± 0.1	32 ± 2	34 ± 2	0.94 ± 0.06

p<0.05 vs. vehicle

^**

p<0.01 vs. vehicle

^***

p<0.001 vs. vehicle

^{^^}

p<0.01 vs. morphine

^{^^^}

p<0.001 vs. morphine

p<0.05 vs. 7 day same treatment

p<0.05 vs. 14 day same treatment, all values reported as mean ± S.E.