Mechanisms of beta sympathomimetic action on neonatal glucose homeostasis in the lamb.
Beta sympathomimetic drugs are used clinically to inhibit premature labor. Significant alterations in glucose homeostasis have been documented in both mother and offspring. To determine the mechanism(s) of beta sympathomimetic drugs on neonatal glucose homeostasis, ritodrine hydrochloride was infused in a newborn term lamb model of glucose kinetics by a crossover design. There was a progressive rise in plasma glucose concentration and plasma insulin concentration during ritodrine hydrochloride infusion compared with the control (saline) infusion. The rise in plasma glucose concentration was associated with a progressive rise in Ra (rate of appearance, production) and Rd (rate of disappearance, utilization). The ritodrine hydrochloride-infused animals had a progressive rise in [insulin/glucose] compared with our prior studies in the newborn lamb, suggesting direct stimulation of pancreatic beta cell secretion. In the neonatal lamb, beta sympathomimetic drugs directly stimulate both hepatic glucose production and pancreatic beta cell secretion. These effects explain, in part, why infants of mothers infused with ritodrine hydrochloride may evidence alterations in neonatal glucose homeostasis.
Tenenbaum
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Cowett
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D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D005947:Glucose / Q000096:biosynthesis / Q000378:metabolism*; D006339:Heart Rate / Q000187:drug effects; D006706:Homeostasis / Q000187:drug effects; D006801:Humans; D007231:Infant, Newborn; D007328:Insulin / Q000097:blood; D007515:Islets of Langerhans / Q000187:drug effects; D008099:Liver / Q000378:metabolism; D007752:Obstetric Labor, Premature / Q000517:prevention & control; D011247:Pregnancy; D012312:Ritodrine / Q000494:pharmacology; D012756:Sheep
D000318:Adrenergic beta-Agonists; D001786:Blood Glucose; D007328:Insulin; D012312:Ritodrine; D005947:Glucose