Table 1.

Physiological variables at baseline and 30-, 60-, and 90-min postintrathecal drug injections of vehicle, 5-HT_2B, 5-HT₇, or 5-HT_2B and 5-HT₇ receptor agonists

	Time, min	Vehicle	5-HT2B	5-HT7	5-HT2B + 5-HT7
$P{a}_{CO}{}_{{}_2}$, mmHg	Baseline	45.0 ± 0.5	48.2 ± 1.5	45.7 ± 1.5	45.3 ± 0.9
	30	45.3 ± 0.8	48.6 ± 1.4	46.5 ± 1.7	45.9 ± 1.2
	60	45.5 ± 0.5	49.1 ± 1.6	46.2 ± 1.6	45.5 ± 1.1
	90	45.0 ± 0.7	48.3 ± 1.6	45.9 ± 1.5	45.3 ± 1
$P{a}_O{}_{{}_2}$, mmHg	Baseline	303 ± 13	284 ± 20	262 ± 18	319 ± 15
	30	291 ± 12	277 ± 25	264 ± 18	306 ± 20
	60	292 ± 9	273 ± 25	258 ± 22	297 ± 21
	90	288 ± 9	262 ± 19	263 ± 17	293 ± 27
sBE, mmol/l	Baseline	0.4 ± 0.5	0.8 ± 0.7	−0.4 ± 0.6	−0.7 ± 0.6
	30	−0.2 ± 0.5	0.7 ± 0.5	−0.2 ± 0.6	−0.3 ± 0.7
	60	0.7 ± 0.5	0.2 ± 0.6	−0.1 ± 0.7	−0.5 ± 0.4
	90	−0.6 ± 0.4	−0.2 ± 0.4	0.4 ± 0.8	−0.6 ± 0.5
MAP, mmHg	Baseline	131 ± 6	128 ± 7	136 ± 7	114 ± 5
	30	130 ± 7	123 ± 7	138 ± 7	104 ± 3
	60	126 ± 7	123 ± 8	137 ± 6	98 ± 3
	90	124 ± 5	118 ± 8	132 ± 7	94 ± 3

Values are means ± SE. $P{a}_O{}_{{}_2}$, arterial O₂ pressure; $P{a}_{CO}{}_{{}_2}$, arterial CO₂ pressure; 5-HT_2B, serotonin 2 receptor; 5-HT₇, serotonin 7 receptor; sBE, standard excess base; MAP, mean arterial pressure.