Table 1.

Comparison of lateral vein and caudal ventral artery sympathetic activities

Variable	Caudal ventral artery	Lateral vein
MABP (mmHg)	95 ± 3	98 ± 2 (n.s.)
	(n = 17)	(n = 17)
Phrenic frequency (Hz)	0.70 ± 0.05	0.65 ± 0.03 (n.s.)
	(n = 17)	(n = 14)
DSR frequency (Hz)	0.83 ± 0.03	0.82 ± 0.05 (n.s.)
	(n = 17)	(n = 14)
Mean unit firing	1.78 ± 0.24	1.62 ± 0.70 (n.s.)
frequency (Hz)	(n = 17)	(n = 14)
Unit firing pattern†
Type A	n = 3*	n = 3
Type B	n = 7*	n = 2
Type C	n = 7*	n = 9
Total	n = 17	n = 14
Units showing no rhythm in autocorrelogram	1/18*	3/17
Percentage time not firing rhythmically (300 s)	15*	23

MABP, mean arterial blood pressure. DSR, dominant sympathetic rhythm. n.s., not significantly different to caudal ventral artery values.

^*Authors' unpublished results.

^†No significant difference between artery and vein distributions (G test). Caudal ventral artery data from Johnson & Gilbey (1996), except where indicated.