EARLY LEAD CHALLENGE AND SUBSEQUENT HYPERTENSION IN SPRAGUE-DAWLEY RATS

Objective: The consequences of chronic, low grade lead (Pb) burden fro m earlier exposure on development of hypertension (HT) and cardiovascu lar disease is, at best, controversial, even though many epidemiologic al studies suggest the possibility. Accordingly, we examined ability o f a short-term Pb challenge to cause later developing HT in rats. Meth ods: We gave 12 newly weaned Sprague-Dawley rats (SD) a 1% Pb acetate solution to drink for 6 weeks, while 12 control rats drank water. The rats were further subdivided into groups consuming high and low amount s of sugar. All rats were followed for 4 months after cessation of the Ph challenge. Results: Early Pb challenge caused no significant chang es in body weight (BW) from controls; however, systolic blood pressure s (SBP) of rats initially receiving Ph continued to rise significantly above their respective dietary controls for months after cessation of challenge. While a high sugar diet alone was associated with elevated SBP, high sugar consumers also challenged with Ph had the highest SBP . Protein excretion did not increase, suggesting, along with other evi dence, a lack of significant renal damage. Conclusion: Previous exposu re to Pb can cause subsequent chronic elevations in SBP.