Endogenous opioids interact in stress-induced hyperglycemia in mice

Intermittent inescapable foot shock stress for 1 hour elicited significant hyperglycemia in mice. Pretreatment with the long acting narcotic antagonist naltrexone (1.0 mg/kg, 1 hr prior to stress) prevented stress hyperglycemia. Naltrexone did not affect blood glucose in unstressed control mice. These findings suggest the involvement of endogenous opioids in the hyperglycemic response to stress in mice. The possible mode of interaction of endorphin in stress hyperglycemia is discussed.