Exposure to stress differential vascular adaptive response in spontaneously hypertensive and Wistar rats: Role of nitric oxide, and prehypertensive and hypertensive states
Stress-induced vascular adaptive response in SHR was investigated, focusing on the endothelium. Noradrenaline responses were studied in intact and denuded aortas from 6-week-old (prehypertensive) and 14-week-old (hypertensive) SHR and age-matched Wistar rats submitted or not to acute stress (20-min...
Saved in:
Published in | Life sciences (1973) Vol. 79; no. 7; pp. 646 - 653 |
---|---|
Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Netherlands
10.07.2006
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Stress-induced vascular adaptive response in SHR was investigated, focusing on the endothelium. Noradrenaline responses were studied in intact and denuded aortas from 6-week-old (prehypertensive) and 14-week-old (hypertensive) SHR and age-matched Wistar rats submitted or not to acute stress (20-min swimming and 1-h immobilization 25 min apart), preceded or not by chronic stress (2 sessions 2 days apart of 1-h day immobilization for 5-consecutive days). Stress did not alter the reactivity of denuded aorta. Moreover, no alteration in the EC50 values was observed after stress exposure. In intact aortas, acute stress-induced hyporeactivity to noradrenaline similar between strains at both age. Chronic stress potentiated this adaptive response in 6- and 14-week-old Wistar but not in 6-week-old SHR, and did not alter the reactivity of 14-week-old SHR. Maximum response (g) in intact aortas [6-week-old: Wistar 3.25+/-0.12, Wistar/acute 1.95+/-0.12*, Wistar/chronic 1.36+/-0.21*(+), SHR 1.75+/-0.11, SHR/acute 0.88+/-0.08*, SHR/chronic 0.85+/-0.05*; 14-week-old: Wistar 3.83+/-0.13, Wistar/acute 2.72+/-0.13*, Wistar/chronic 1.91+/-0.19*(+), SHR 4.03+/-0.17, SHR/acute 2.26+/-0.12*, SHR/chronic 4.10+/-0.23; inside the same strain: *P < 0.05 relate to non-stressed rat, +P < 0.05 related to acute stressed rat; n = 6-18]. Independent of age and strain, L-NAME and endothelium removal abolished the stress-induced aorta hyporeactivity.
The vascular adaptive response to stress is impaired in SHR, independently of the hypertensive state. Moreover, this vascular adaptive response is characterized by endothelial nitric oxide-system hyperactivity in both strains. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0024-3205 |
DOI: | 10.1016/j.lfs.2006.02.007 |