The effects of hexoprenaline, a beta 2-sympathomimetic drug, on maternal glucose, insulin, glucagon, and free fatty acid levels.

Hexoprenaline, an adrenergic beta 2-receptor agonist, was administered as a 10 microgram intravenous bolus to 9 women in the third trimester of pregnancy. The maternal plasma glucose, serum immunoreactive insulin, plasma immunoreactive glucagon (IRG 30 K), and free fatty acid (FFA) concentrations rose significantly at different times following the bolus injection. Thc serum insulin level increased first and reached a peak at 10 minutes, before the rise in plasma glucose, which reached a maximum at 30 minutes, suggesting that beta 2-receptor stimulation affects insulin secretion directly and not via a rise in the glucose level. Plasma glucagon and FFA levels also rose despite the rise in glucose levels. We therefore conclude that beta 2-receptor stimulation has direct actions on insulin and glucagon release and on glucose and FFA metabolism. The possible fetal sequelae due to these changes in the maternal metabolic milieu are discussed in relation to the use of a 10 microgram intravenous bolus of hexoprenaline as a measure in the treatment of acute fetal distress.