Beta Adrenergic Receptor Mechanisms in the Metabolic Effects of Diazoxide in Fasted Rats

The role of beta adrenergic receptor mechanisms in the metabolic effects of diazoxide was assessed in anesthetized fasted or partially refed rats using the beta blocker pro-pranolol. The prior administration of propanolol significantly inhibited the expected diazoxide-induced increases in blood sugar, plasma lactate and glycerol. Also, propranolol blockade of diazoxide hyperglycemie was more effective in fasted than partially refed rats. It was concluded that diazaxide hyperglycemia in fasted rats is accompanied by increases in plasma lactate and glycerol as a consequence of beta adrenergic receptor stimulation. These observations indicate that extrapancreatic beta receptor catecholamine factors are important in diazoxide-induced hyperglycemia and support the theory for at least a partial role of catecholamine mechanisms in the metabolic effects of diazoxide.