The effects of a 1 h continuous infusion of doxorubicin (12.5 mg kg-1, 200 mg M-2) on blood chemistry was examined in rabbits over a 6-h period. Plasma glucose levels remained unchanged while insulin levels were significantly decreased to 39, 45 and 61% of the zero time value (12.8 +/- 2.9 ng ml-1) at 30, 60 and 120 min, respectively, after starting the drug infusion. Plasma cortisol levels were increased to 141, 140 and 131% of the initial zero time value (12.3 +/- 2.2 ng ml-1) at 120, 240 and 360 min, respectively. Doxorubicin had no effect on plasma electrolytes, osmolality and urea nitrogen but significantly increased plasma creatinine over the corresponding control value (2.2 +/- 0.8 micrograms ml-1 to 4.9 +/- 0.7 micrograms ml-1) at 120 min and the level remained elevated for the remaining period of the study. Systolic and diastolic pressure, and heart rate were also depressed at 240 and 360 min. The data collected in the present study indicate that the doxorubicin infusion might have a direct effect on beta cells in the pancreas as well as muscle tissue. Changes in cortisol, blood pressure and heart rate appear to be secondary to other effects produced by doxorubicin.