Cardiovascular response to stress after middle cerebral artery occlusion in rats

Brain Res. 1997 Feb 7;747(2):181-8. doi: 10.1016/s0006-8993(96)01137-7.

Abstract

Previously, we have shown cardiovascular and autonomic disturbances in male Wistar rats following middle cerebral artery occlusion (MCAO). Using this model, neurochemical changes, that were maximal at 3-5 days and subsiding by day 10, were observed unilaterally in the insular cortex and amygdala. The amygdalar neurochemical changes may be related to the stroke-induced cardiovascular disturbances, since the amygdala is critical in mediating the cardiovascular responses to stress. We examined the cardiovascular responses to intermittent and continuous noise and air-jet stimulation in male Wistar rats on days 2-10 after right-sided MCAO or sham MCAO. Compared to the sham MCAO rats, intermittent noise elicited significant tachycardiac responses on days 5 and 7 after stroke. Air-jet stimulation also elicited a significant tachycardic response on day 5, whereas continuous noise produced significant tachycardiac and pressor responses at days 5 and 7, respectively, in the MCAO rats compared to the control rats. Analyses on the heart rate variability using fast Fourier transformation revealed significant increases in the normalized mid-frequency spectral power on day 7 for intermittent noise and air-jet stimulation, suggesting increases in the sympathetic activity. These results indicate a time-course of exaggerated cardiovascular responses to stress and suggest a state of susceptibility to cardiac perturbations in rats following stroke.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amygdala / physiopathology
  • Animals
  • Arterial Occlusive Diseases / physiopathology*
  • Blood Pressure / physiology*
  • Cerebral Arteries / physiopathology*
  • Cerebral Cortex / physiopathology
  • Electrocardiography
  • Fourier Analysis
  • Heart Rate / physiology*
  • Male
  • Rats
  • Rats, Wistar
  • Stress, Physiological / physiopathology*