Table 2.

Effects of congenic strains on blood pressure, body weight, heart weight, and heart weight-to-body weight ratio

Congenic StrainBlood Pressure, mmHgHeart Weight/Body Weight, mg/g
Dahl SCongenicEffect*t-testDahl SCongenicEffect*t-test
S.LEW(chr1)212 [3.76]177 [1.35]−34 (4.08)0.00013.987 [0.031]3.564 [0.028]−0.422 (0.041)0.0001
Chr1×14227 [4.26]203 [2.58]−23 (4.98)0.00014.272 [0.060]3.974 [0.030]−0.297 (0.067)0.0001
Chr1×15202 [1.72]207 [2.87]+5 (3.35)0.1063.834 [0.037]3.881 [0.034]+0.047 (0.051)0.361
Chr1×8211 [2.68]184 [1.95]−26 (3.31)0.00014.017 [0.022]3.766 [0.037]−0.251 (0.043)0.0001
Chr1×7224 [4.94]225 [3.71]+1 (6.18)0.8634.088 [0.058]4.089 [0.038]+0.001 (0.069)0.991
Chr1×3231 [3.30]192 [1.47]−38 (3.49)0.00014.334 [0.042]3.867 [0.022]−0.466 (0.048)0.0001
Congenic StrainBody Weight, gHeart Weight, mg
Dahl SCongenicEffect*t-testDahl SCongenicEffect*t-test
S.LEW(chr1)305 [2.57]310 [2.43]+5 (3.54)0.1691217 [11.12]1106 [10.69]−111 (15.43)0.0001
Chr1×14293 [2.11]307 [2.75]+13 (3.47)0.00011261 [15.86]1212 [11.87]−49 (19.81)0.018
Chr1×15318 [3.57]329 [2.27]+10 (4.23)0.0231206 [23.10]1292 [17.53]+86 (29.00)0.006
Chr1×8291 [3.90]295 [2.91]+4 (4.86)0.3611169 [16.58]1114 [17.29]−55 (23.95)0.026
Chr1×7296 [3.01]303 [2.92]+7 (4.20)0.1011210 [19.35]1239 [16.60]+29 (25.50)0.254
Chr1×3294 [4.02]294 [2.63]0 (4.81)0.9091273 [14.53]1139 [11.85]−133 (18.60)0.0001
  • Dahl S and congenic values are means; nos. in square brackets are SEs.

  • * Effect values = congenic value − Dahl S value; nos. in parentheses are SEs of mean differences. Experimental design: 20 male Dahl S rats and 20 male rats of a given congenic strain were age matched and housed and raised together. Blood pressures were determined in a blinded fashion (see materials and methods). Comparison was only made between matched sets of Dahl S and congenic rats. Congenic strains are defined in Fig. 1.

  • Because body weight was different between the congenic strains Chr1 × 14 or Chr1 × 15 and Dahl S, heart weight values were corrected for body weight using regression between heart weight and body weight (28).