| Full text | |
| Author(s): |
Fazan, Jr., Rubens
[1]
;
de Oliveira, Mauro
[1]
;
Oliveira, Jose Antonio C.
[1]
;
Salgado, Helio C.
[1]
;
Garcia-Cairasco, Norberto
[1]
Total Authors: 5
|
| Affiliation: | [1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Physiol, BR-14049900 Ribeirao Preto, SP - Brazil
Total Affiliations: 1
|
| Document type: | Journal article |
| Source: | Epilepsy & Behavior; v. 22, n. 4, p. 666-670, DEC 2011. |
| Web of Science Citations: | 15 |
| Abstract | |
We evaluated autonomic cardiovascular modulation and baroreflex control of heart rate (HR) in a particular epileptic rat strain, Wistar audiogenic rats (WARs). We studied spontaneous baroreflex sensitivity as well as reflex changes in HR evoked by phenylephrine/nitroprusside-induced changes in arterial pressure (AP). Atropine and propranolol were used to measure cardiac autonomic tone. AP and pulse interval (PI) variability analysis were performed in the time and frequency domains (FFT spectral analysis) to evaluate cardiovascular sympatovagal modulation in WARs. AP and HR were higher in WARs (109 +/- 2 mm Hg and 366 +/- 9 bpm) than in Wistar control rats (101 +/- 2 mm Hg and 326 +/- 10 bpm). The power of the low-frequency band of both AP and PI spectra, a marker of sympathetic modulation, was higher in WARs than in Wistar control rats. The high-frequency power of the PI spectra in normalized units, which is linked to cardiac vagal modulation, was lower in WARS. Both WARs and Wistar control rats had similar vagal tone (91 +/- 13 bpm vs 94 +/- 11 bpm, respectively), but sympathetic tone was higher in WARS (30 +/- 4 bpm vs 14 +/- 4 bpm). No differences were detected in the gain of evoked (1.32 +/- 0.1 ms/mm Hg vs 135 +/- 0.2 ms/mm Hg) or spontaneous (1.34 +/- 0.2 ms/mm Hg vs 2.04 +/- 0.2 ms/mm Hg) baroreflex sensitivity. The higher AP and HR and the autonomic imbalance (sympathetic predominance) in WARs might be associated with an increased risk of life-threatening cardiovascular events in this strain. (C) 2011 Elsevier Inc. All rights reserved. (AU) | |
| FAPESP's process: | 05/56447-7 - Research through images from high field magnetic resonance aimed at studies in humans |
| Grantee: | João Pereira Leite |
| Support Opportunities: | Inter-institutional Cooperation in Support of Brain Research (CINAPCE) - Thematic Grants |