AJP - Regulatory, Integrative and Comparative Physiology, Vol 273, Issue 4 1361-R1366, Copyright © 1997 by American Physiological Society
Cardiovascular responses to vaginocervical stimulation in the spinal cord-transected rat
G. R. Sansone, R. Bianca, R. Cueva-Rolon, L. E. Gomez and B. R. Komisaruk
Institute of Animal Behavior, Rutgers, The State University of New Jersey, Newark 07102, USA.
The present study ascertained whether increases in heart rate (HR) and
systolic blood pressure (SBP) produced by vaginocervical stimulation (VS;
500 g force) persist in the unanesthetized rat after chronic spinal cord
transection at selected levels. Three groups were used: spinal cord
transection at T7 (n = 10) or L5 (n = 10) or a sham-operated control group
(Sh, n = 10). In the Sh group, VS increased significantly both HR, by 95
+/- 14.3 beats/min (bpm) (22 +/- 3.7% above baseline), and BP, by 37 +/-
5.7 mmHg (37 +/- 7.7% above baseline), confirming earlier findings. In the
T7 group, VS significantly decreased HR by 107 +/- 21.4 bpm (27 +/- 4.1%
below baseline) and increased BP by 41.3 +/- 12.9 mmHg (32 +/- 8.3% above
baseline). In response to VS, HR increased in every rat in the Sh group and
decreased in every rat in the T7 group. In the L5 group, VS failed to
significantly affect HR or BP. In the present study, specific levels of
spinal cord transection produced differential HR and BP responses to VS in
the rat. A model is presented addressing the component responses of
autonomic dysreflexia that can occur, contingent on the level of spinal
cord injury, in women during parturition or sexual intercourse.
