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

ABSTRACT

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+ 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+ and K+, and urine flow rate were increased by Cd intoxication. Interestingly, the ratio of Na+/K+ 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+ excretion and urine flow rate in both groups. Therefore, the increase in the urine volume seemed to enhance the excretion of K+. This study strongly suggest that the hypotensive effect of Cd is mediated by systemic Na+ loss through the kidney and/or hypovolemia via fluid-shift.