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Changes in cardiovascular variability in response to stress in rats with two different forms of hypertension
Author(s) -
Hayward Linda F,
Hernandez Morgan,
Castellanos Mabelin
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.703.18
Subject(s) - medicine , endocrinology , blood pressure , baroreflex , heart rate
Previously our lab demonstrated an association between an exaggerated response to air jet stress (AJS) in the spontaneously hypertensive rat (SHR) and dysregulation of corticotrophin (CRH) peptide expression in the amygdala (CEA). Changes in the production and release of CEA‐CRH have also been linked to elevated salt‐intake. The present study aimed to evaluate the stress response in normotensive (Sprague Dawley, SD) and hypertensive (SHR vs SD‐DOCA‐salt) rats. Adult 12 wk old male rats (3 to 4/group) were chronically instrumented for blood pressure (BP) and heart rate (HR) measurement and exposed to 20 min. of AJS. At rest, systolic BP variability in the VLF was significantly elevated in the both SHR and SD‐DOCA compared to the SD, and this corresponded to a significantly elevated resting BP (163±6 mmHg). During AJS, the rise in BP was significantly elevated in the SHR compared to both the SD‐DOCA and SD (30±1 vs 20±2 vs 17±2 mmHg, respectively). Alternatively, the rise in HR was lower in the SD‐DOCA. In both the SHR and SD‐DOCA rats HR remained elevated for 10 min post‐AJS compared to the SD. Differences in HR were paralleled by evidence of altered HR HF power during AJS in the SD‐DOCA and altered baroreflex function post stress in the SD‐DOCA and SHR. These data suggest that although high salt intake triggers a sustained hypertension comparable to the SHR, the response to stress is different.