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Strain Dependent differences in variance of heart rate and mean arterial pressure in normotensive rats
Author(s) -
Lau Catherine,
Llamas Bastien,
Deschepper Christian,
Cupples William A
Publication year - 2006
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.20.4.a313-b
Subject(s) - heart rate , offspring , blood pressure , medicine , mean arterial pressure , biology , endocrinology , standard deviation , zoology , genetics , pregnancy , statistics , mathematics
Variability of heart rate and of blood pressure (BP) are recognized risk factors for cardiovascular disease. BP is known to vary among inbred, normotensive rat strains, suggesting genetic control of cardiovascular variables. We assessed BP by telemetry 12–14 days after transmitter implantation in two normotensive strains and their offspring. Heart rate and mean BP were acquired every 2 minutes for 24 hrin 11 Brown Norway (BN) rats, 5 Wistar Kyoto (WK), 23 F1 offspring of BN × WK cross, and in 201 F2 (F1 × F1) rats. Average heart rate did not differ among the groups (WK–316±6, BN–319±4, F1–315±2, F2–318±1 (mean± SEM)) although heart rate variability, is expressed as standard deviation of the 24‐hour record, was higher in WK rats (38.9±1.2) than in BN rats (30.0±1.0); both F1(36.7±1.0) and F2 (38.3±0.4) had heart rate standard deviations that were similar to the parental WK strain. In contrast, BP was lower in BN rats (88±1mmHg) than in F1 (90±1), F2 (93±1), or WK (100±3). Standard deviation of BP was higher in WK rats (9.3±0.5) than in BN (7.1±0.2) and in this case both F1 (7.0±0.2) and F2 (7.5±0.1) more closely resembled the parental BN strain. These results suggest WK‐dominant inheritance of heart rate variance and BN‐dominant inheritance of BP variance. The absence of a Mendelian assortment in F2 rats suggests contributions by more than one gene to variation of both heart rate variance and BP variance. Funded by NHLBI.