Beta-endorphin does not alter the plasma glucose concentration in the conscious dog. beta-Endorphin (4 X 10(-8) M to 4 X 10(-10) M) given intravenously did not alter the plasma glucose concentration in the conscious dog. This demonstrates that beta-endorphin does not modulate glucose homeostasis in the conscious dog. The results support the concept that beta-endorphin does not have an anorexic effect in the conscious dog.