SUMMARY1. The cardiovascular effects of sodium glutamate were investigated in anaesthetized dogs with bolus injections, intravenous infusions and rabbit isolated papillary muscles.2. The intravenous bolus injections of sodium glutamate resulted in slight, transient decreases in contractile force at doses of 58 and 117 mg/kg, which were followed by brief increases in blood pressure.3. Sodium glutamate had no effect on contractile responses of isolated papillary muscles at any of the concentrations used.4. Infusions of glutamate produced no change in blood pressure, an increase in cardiac output, and a decrease in heart rate, total peripheral resistance and femoral vascular resistance.5. The infusion of sodium glutamate into animals with no renal function resulted in an increased plasma osmolality and a decreased haematocrit.6. The results from this study show that sodium glutamate had minimal cardiovascular effects. The results from the infusion data suggest that glutamate increases intravascular volume by an osmotic effect.