INSULIN RESISTANCE AND BLOOD-PRESSURE IN DAHL RATS AND IN ONE-KIDNEY, ONE-CLIP HYPERTENSIVE RATS

In normal rats, sucrose feeding results in insulin resistance and an elevation of arterial pressure. The purpose of this study was twofold: 1) to evaluate the effect of sucrose feeding on blood pressure in a genetic model and in an acquired model of hypertension and 2) to determine whether these models of hypertension are associated with insulin resistance. In Dahl salt-resistant (Dahl-R) rats on both a 0.45 and a 3% NaCl intake, systolic blood pressures were higher (P < 0.01) in sucrose-drinking than in water-drinking animals. In contrast, blood pressure was not affected by dietary sucrose in Dahl salt-sensitive (Dahl-S) rats. Blood pressure was also not affected by sucrose in the one-kidney, one-clip (1K,1C) hypertensive rat. In response to an oral glucose load, serum glucose was similar in Dahl-R and Dahl-S rats, although serum insulin was higher (P < 0.05) in Dahl-S rats, suggesting that Dahl-S rats are insulin resistant. In contrast, glucose and insulin responses were similar in hypertensive 1K,1C animals and normotensive controls. In conclusion, sucrose feeding increased blood pressure in Dahl-R but not in Dahl-S or 1K,1C hypertensive rats. Additionally, Dahl-S rats, but not hypertensive 1K,1C rats, are insulin resistant.