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Need to measure cardiac size with Dahl salt-sensitive rats
J O U R NA L OF PR O TE O MI CS 7 4 ( 2 01 1 ) 2 2 2 0
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Letter to the Editor Need to measure cardiac size with Dahl salt-sensitive rats The report of Grussenmeyer et al. [1] is very interesting. However, a weakness is that cardiac size was not measured and it was assumed that cardiac hypertrophy developed only on a high saltdiet in the Dahl S rats. That the hearts from the two strains are the same size in this study is important to empirically confirm since there is evidence that S rats have hypertension on low salt diets and this is a model of pressure-induced cardiac hypertrophy. At ten weeks of age on 0.1% NaCl diet mean systolic BP by tail-cuff measurements by Harlan contract services was 176±7 mmHg (n=15). At 23 weeks on a 0.3% they are reported to have BP of approx. 170 mmHg [2]. The ages, weights, and heart sizes of the rats are not reported in the present publication. This hypertension on a low salt diet could be, in part, due to the breeding strategy which according to Harlan communications with myself selects rats with salt-independent hypertension, i.e., rats with BP>160 mmHg on 0.1% NaCl diet, for breeding into the colony. Thus, it is possible that both Dahl S rats on the low salt diets have some hypertrophy and that inferences made that differences in Dahl S and Dahl R rats on a low Na diet are due to strain differences may be incorrect, but rather, in part due to cardiac hypertrophy in the Dahl S rat strain on a low Na diet.
REFERENCES [1] Grussenmeyer, et al. Proteome analysis in cardiovascular pathophysiology using the Dahl rat model. J Proteomics 2011: 672–82. [2] Chandramohan, et al. Role of γ melanocyte-stimulating hormone–renal melanocortin 3 receptor system in blood pressure regulation in salt-resistant and salt-sensitive rats. Metabolism 2009;58:1424–9.
1874-3919/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.jprot.2011.06.024
Robert Danziger University of Illinois at Chicago, Medicine and Physiology, 840 S. Wood St., Chicago, IL 60612, United States E-mail address: [email protected]. 12 May 2011
available at www.sciencedirect.com
www.elsevier.com/locate/jprot
Letter to the Editor Need to measure cardiac size with Dahl salt-sensitive rats The report of Grussenmeyer et al. [1] is very interesting. However, a weakness is that cardiac size was not measured and it was assumed that cardiac hypertrophy developed only on a high saltdiet in the Dahl S rats. That the hearts from the two strains are the same size in this study is important to empirically confirm since there is evidence that S rats have hypertension on low salt diets and this is a model of pressure-induced cardiac hypertrophy. At ten weeks of age on 0.1% NaCl diet mean systolic BP by tail-cuff measurements by Harlan contract services was 176±7 mmHg (n=15). At 23 weeks on a 0.3% they are reported to have BP of approx. 170 mmHg [2]. The ages, weights, and heart sizes of the rats are not reported in the present publication. This hypertension on a low salt diet could be, in part, due to the breeding strategy which according to Harlan communications with myself selects rats with salt-independent hypertension, i.e., rats with BP>160 mmHg on 0.1% NaCl diet, for breeding into the colony. Thus, it is possible that both Dahl S rats on the low salt diets have some hypertrophy and that inferences made that differences in Dahl S and Dahl R rats on a low Na diet are due to strain differences may be incorrect, but rather, in part due to cardiac hypertrophy in the Dahl S rat strain on a low Na diet.
REFERENCES [1] Grussenmeyer, et al. Proteome analysis in cardiovascular pathophysiology using the Dahl rat model. J Proteomics 2011: 672–82. [2] Chandramohan, et al. Role of γ melanocyte-stimulating hormone–renal melanocortin 3 receptor system in blood pressure regulation in salt-resistant and salt-sensitive rats. Metabolism 2009;58:1424–9.
1874-3919/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.jprot.2011.06.024
Robert Danziger University of Illinois at Chicago, Medicine and Physiology, 840 S. Wood St., Chicago, IL 60612, United States E-mail address: [email protected]. 12 May 2011