Vol. 283, Issue 3, H1181-H1190, September 2002
A new inbred Wistar-Kyoto rat substrain exhibiting apparent
salt sensitivity and borderline hypertension
Adamu
Alemayehu,
Laura
Breen, and
Morton P.
Printz
Department of Pharmacology, University of California San
Diego, La Jolla, California 92093-0636
The normotensive Wistar-Kyoto
(WKY) rat strain is a traditional control for the spontaneously
hypertensive rat (SHR). We found trait differences between two inbred
normotensive WKY strains, derived originally from different vendors,
and compared these two strains from La Jolla-Taconic Farms (WKY/lj-tf)
and La Jolla-Charles River (WKY/lj-cr) with the inbred SHR/lj-cr for
cardiovascular, diurnal, and activity traits under normal and high
(8%) NaCl diets. Marked genetic diversity was found between the two
vendor-derived WKY. By using an extended study design and
radiotelemetry, we compared WKY/lj-cr, WKY/lj-tf, and SHR/lj-cr with
the following results: systolic pressure (120 ± 1, 133 ± 1, 168 ± 3 mmHg, respectively); diurnal variation in heart rate
(
HR: 46 ± 3, 71 ± 4, 57 ± 2 beats/min, respectively); and salt sensitivity of arterial pressure (systolic: 10 ± 1, 21 ± 1, 20 ± 1 mmHg, respectively). The
WKY/lj-tf genotype apparently results in compromised control of
arterial pressure and heart rate, especially during high NaCl intake,
and greater susceptibility to high pressure (i.e., high NaCl-induced
secondary changes). WKY/lj-tf thus constitutes a new inbred borderline
hypertensive WKY substrain offering unique opportunities for genomic
studies into the development of genetic hypertension.
inbred strains; hypertension sodium-dependent; genotype; circadian
rhythm; radiotelemetry; heart rate; polymorphism
