Table 1.

Pregnant llama arterial blood gases and acid/base status

	Normoxia	Hypoxia	Recovery
pHa
Saline	7.43 ± 0.02	7.49 ± 0.02	7.46 ± 0.02
V1 antagonist	7.46 ± 0.02	7.50 ± 0.02	7.49 ± 0.02
Phentolamine	7.44 ± 0.01	7.46 ± 0.05	—
Pa,CO2(mmHg)
Saline	36.8 ± 1.1	32.8 ± 0.8*	34.1 ± 1.6
V1 antagonist	36.4 ± 0.6	31.9 ± 1.1*	33.7 ± 1.5
Phentolamine	33.9 ± 3.4	34.7 ± 3.1	—
Pa,O2(mmHg)
Saline	89.8 ± 1.7	34.5 ± 1.7*	86.0 ± 3.4
V1 antagonist	88.8 ± 3.1*	32.4 ± 2.5*	81.4 ± 3.9
Phentolamine	85.3 ± 5.6	39.0 ± 5.9*	—
%satHb
Saline	93.5 ± 1.6	74.6 ± 2.3*	93.5 ± 1.5
V1 antagonist	94.5 ± 1.2	71.3 ± 3.8*	94.3 ± 1.6
Phentolamine	93.2 ± 2.1	68.7 ± 13.5*	—
[Hb](g dl−1)
Saline	9.8 ± 0.3	11.0 ± 0.4	10.2 ± 0.3
V1 antagonist	9.9 ± 0.4	11.7 ± 0.5	10.2 ± 0.4
Phentolamine	9.8 ± 0.5	10.9 ± 0.4	—
O2 capacity (vol. % O2)
Saline	13.1 ± 0.4	14.7 ± 0.5	13.6 ± 0.4
V1 antagonist	13.3 ± 0.6	15.6 ± 0.6*	13.6 ± 0.5
Phentolamine	13.1 ± 0.7	14.7 ± 0.5	—
O2 content (vol. % O2)
Saline	12.3 ± 0.5	11.0 ± 0.6	12.8 ± 0.5
V1 antagonist	12.6 ± 0.6	11.1 ± 0.8	12.9 ± 0.7
Phentolamine	12.3 ± 0.9	10.1 ± 2.2	—
Base excess (mequiv l−1)
Saline	−0.6 ± 1.1	1.7 ± 1.3	0.9 ± 1.4
V1 antagonist	1.9 ± 1.2	1.3 ± 0.9	2.3 ± 0.6
Phentolamine	−1.1 ± 1.7	1.0 ± 2.5	—

Values are means ± s.e.m. of all values obtained during each of the experimental hours when the fetuses were infused with saline, V₁ antagonist, or phentolamine. pH_a, arterial pH; P_a,CO2, arterial CO₂ pressure; P_a,O2, arterial O₂ pressure; %satHb, percentage saturation of Hb. Significant differences (P < 0.05)

^*hypoxia or recovery vs. normoxia (ANOVA + Student-Newman-Keuls test).