Changes of Hemodynamics and Renal Function due to Acute Cadmium Exposure in Rats

Changes of Hemodynamics and Renal Function due to Acute Cadmium Exposure in Rats

The systolic and diastolic pressures in anesthetized Sprague-Dawley male rats were greatly decreased after single-dose of Cd treatment without significant changes in heart rate. There was a fluid-shift into the third space and/or -loss through the kidney, since plasma Na<SUP>&#8290;</SUP> concentration and hematocrit ratio were significantly increased by acute Cd exposure. The present study showed that the sustained hypotensive effect of single-dose Cd on the cardiovascular system might have resulted from the systemic hypovolemia. Furthermore, renal excretion of electrolytes, including Na<SUP>&#8290;</SUP> and K<SUP>&#8290;</SUP>, and urine flow rate were increased by Cd intoxication. Interestingly, the ratio of Na<SUP>&#8290;</SUP>/K<SUP>&#8290;</SUP> excretion was increased and reached the maximum level 3 hours after Cd injection and returned to the normal level after 7 hours. Nevertheless, there was no difference in the regression analysis of K<SUP>&#8290;</SUP> excretion and urine flow rate in both groups. Therefore, the increase in the urine volume seemed to enhance the excretion of K<SUP>&#8290;</SUP>. This study strongly suggest that the hypotensive effect of Cd is mediated by systemic Na<SUP>&#8290;</SUP> loss through the kidney and/or hypovolemia via fluid-shift.