Abstract
In both animals and humans, stimuli leading to sympathetic activation are accompanied by an impairment of the baroreceptor-heart rate reflex. To determine whether sympathetic activity normally interferes with this reflex function we examined in conscious Wistar-Kyoto (WKY) rats the effect of chemical sympathectomy by 6-hydroxydopamine on the bradycardic response to baroreceptor stimulation induced by raising blood pressure via intravenous phenylephrine boluses; control rats received vehicle. Spontaneously hypertensive rats were also studied because in these animals there is both a baroreceptor reflex impairment and a sympathetic overactivity. Baroreceptor reflex sensitivity, calculated as the ratio of the peak increase in pulse interval to the peak increase in mean arterial pressure, was 75% greater in sympathectomized WKY rats than in control WKY rats (1.28±0.15 versus 0.73±0.10 msec/mm Hg, mean±SEM; p
| Original language | English |
|---|---|
| Pages (from-to) | 230-235 |
| Number of pages | 6 |
| Journal | Hypertension |
| Volume | 18 |
| Issue number | 2 |
| Publication status | Published - 1991 |
ASJC Scopus subject areas
- Internal Medicine