Document Detail


Blood pressure and heart rate development in young spontaneously hypertensive rats.
MedLine Citation:
PMID:  9530190     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The course of hypertension development in young spontaneously hypertensive rats (SHR) was studied by the measurement of changes in systolic blood pressure (BP), body weight, and heart rate (HR) at 2, 3, 4, and 6 wk of age. To achieve this, we compared inbreeding lines of SHR and Wistar-Kyoto rats (WKY) to determine if differences in BP, body weight, or HR were present among inbreeding lines of the same strain or between strains. The effect of these differences on the eventual level of BP was then assessed. We found that BP began to diverge between SHR and WKY at 4 wk of age. Significant differences in systolic BP (24 mmHg) between SHR inbreeding lines at 4 wk of age did not affect the BP at 8 wk (172 vs. 170 mmHg). Pulse pressure was significantly higher in SHR than in WKY at 4 wk of age. HR was elevated in SHR over age-matched WKY at 3 wk of age and positively correlated to the level of BP attained by individual animals at 6 wk (P = 0.037). Moreover, WKY inbreeding lines showing elevated HR developed higher BP (145 vs. 127 mmHg) at 10-12 and 20 wk of age. The prehypertensive tachycardia in SHR was investigated further and found to result from an increased intrinsic HR. Because HR at 3 wk is a genetic trait that can be partitioned into inbreeding lines, and inbreeding lines most expressive of this trait showed the highest eventual BP, we conclude that prehypertensive tachycardia may be an important first step during hypertension development in SHR. Moreover, early elevations in HR are highly predictive (r = 0.41) of hypertension occurrence in the animal population studied.
Authors:
J G Dickhout; R M Lee
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The American journal of physiology     Volume:  274     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1998 Mar 
Date Detail:
Created Date:  1998-04-14     Completed Date:  1998-04-14     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H794-800     Citation Subset:  IM    
Affiliation:
Department of Anaesthesia, McMaster University, Hamilton, Ontario, Canada.
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MeSH Terms
Descriptor/Qualifier:
Age Factors
Animals
Baroreflex
Blood Pressure
Epinephrine / blood
Heart Rate
Male
Norepinephrine / blood
Rats
Rats, Inbred SHR / physiology*
Rats, Inbred Strains
Rats, Inbred WKY
Tachycardia / physiopathology
Chemical
Reg. No./Substance:
51-41-2/Norepinephrine; 51-43-4/Epinephrine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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