Enhanced monocyte adherence to thoracic aortae from rats with two forms ofexperimental hypertension

To extend our previous observation that thoracic aortae from rats with spon taneous hypertension (SHR) bind monocytoid cells with enhanced avidity, we isolated thoracic aortae from two different forms of rodent hypertension: D ahl salt-sensitive (Dahl-S) rats fed a high salt diet and Sprague-Dawley (S -D) rats fed a fructose-enriched diet. Blood pressure was determined 14 day s after feeding normal chow or chow containing 8% NaCl to Dahl-S and Dahl s alt-resistant (Dahl-R) rats, and either chow or a fructose-enriched diet to S-D and Fischer 344 (F-344) rats. Blood pressure was similar in Dahl-S and Dahl-R rats on the chow diet, but higher in Dahl-S rats in response to the 8% NaCl diet (188 +/- 7 v 137 +/- 3 mm Hg, P < .001). Blood pressure also increased when S-D rats consumed fructose as compared with chow (149 +/- 4 v 128 +/- 2 P < .05), whereas blood pressure did not change with diet in F- 344. Thoracic aortae were removed from rats in each experimental group, and their ability to bind murine monocytoid cells quantified. Measurements of monocyte binding were performed on one experimental and one control rat sim ultaneously, and results presented as the ratio of cells bound by thoracic aortae from the experimental compared with the control rat. With this appro ach, the ratio of monocyte binding (8% NaCl/chow) was increased in Dahl-S v ersus Dahl-R rats (1.7 +/- 0.1 v 1.3 +/- 0.1, P < .05), as well as in S-D a s compared with F-344 rats (1.7 +/- 0.2 v 1.1 +/- 0.1, P < .05). These resu lts provide evidence that hypertension in Dahl-S and fructose-fed S-D rats was associated with changes in the endothelium that favor atherogenesis. Am J Hypertens 1999; 12:890-893 (C) 1999 American Journal of Hypertension, Lt d.