EFFECT OF STRESS ON CARDIOVASCULAR ACTIVITY AND SERUM CHOLESTEROL IN NORMOTENSIVE AND HYPERTENSIVE RATS: PP.29.174

Abstract

Aims: We examined the effect of immobilization stress (60 min) on cardiovascular stress-responses and serum cholesterol levels in normotensive and hypertensive rats. Methods: The experiments were carried out on mongrel male rats. To induce high levels of blood pressure (BP) rats were been clipped at the renal artery with a silver clip (Goldblatt hypertension, 2K, 1C). Rats were instrumented with polyethylene catheters in artery for measuring of mean arterial pressure (MAP) and heart rate (HR). The hemodynamic parameters were measured using PowerLab system for direct recorder of blood pressure signals. Serum total cholesterol was determined with automated methods by a spectrophotometric assay. Results: Results showed that ischemia of kidney was accompanied by development of hypertension. Stress induced greater increase in HR and more prolongation of increase in MAP in hypertensive males vs. normotensive males. The basal cholesterol levels were significant lower in hypertensive males than in normotensive males. Stress resulted to increase in total cholesterol concentration in both groups of rats. Interestingly notice that stressed levels of cholesterol were higher in hypertensive males vs. normotensive males. Conclusion: Thus our data suggest that development of renal hypertension is characterized by decreased basal serum cholesterol. But despite this fact in hypertensive rats vs. normotensive group stress induces more pronounced increase in cardiovascular stress-reactivity which accompanied by more significant increase in serum cholesterol levels.