Pyloric pressure response to insulin-induced hypoglycemia in humans.
The pyloric pressure response to insulin-induced hypoglycemia was studied. Studies were performed in 102 experiments on 38 normal subjects. During insulin-induced hypoglycemia, pyloric pressure increased from 5.5 +/- 1.2 to 10.8 +/- 1.1 mmHg (P less than 0.02). This increase in pyloric pressure ws not due to a direct effect of insulin, duodenal acidification, or the release of corticosteroids or growth hormone. Glucagon doses of 2 and 5 micrograms . kg-1 . h-1 increased pyloric pressure from 4.7 +/- 1.1 to 6.7 +/- 0.5 mmHg (P less than 0.05) and from 4.7 +/- 1.1 to 8.5 +/- 1.1 mmHg (P less than 0.02), respectively. Pyloric pressures were increased to 10.8 +/- 0.9 (P less than 0.01) and 13.0 +/- 1.4 mmHg (P less than 0.01) at 0.1 and 0.2 micrograms . kg-1 . min-1 of epinephrine, respectively. Neither cholinergic blockade nor alpha-adrenergic blockade significantly affected the pyloric pressure response to insulin hypoglycemia. beta-Adrenergic blockade abolished the pyloric pressure responses to both insulin hypoglycemia and epinephrine. Neither beta- nor alpha-adrenergic stimulation altered the basal pyloric pressure. In contrast, the combination of isoproterenol and phenylephrine increased the pyloric pressure significantly from 4.2 +/- 0.8 to 12.0 +/- 1.7 mmHg ( P less than 0.01). These observations suggest that insulin hypoglycemia increases pyloric pressure by an adrenergic mechanism that requires stimulation of both alpha- and beta-receptors.
D001285:Atropine / Q000494:pharmacology; D001786:Blood Glucose / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D004837:Epinephrine / Q000494:pharmacology; D005934:Glucagon / Q000494:pharmacology; D006801:Humans; D007003:Hypoglycemia / Q000139:chemically induced / Q000503:physiopathology*; D007328:Insulin / Q000009:adverse effects / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D010646:Phentolamine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011312:Pressure; D011433:Propranolol / Q000494:pharmacology; D011708:Pylorus / Q000502:physiology*
D001786:Blood Glucose; D007328:Insulin; D010656:Phenylephrine; D001285:Atropine; D005934:Glucagon; D011433:Propranolol; D007545:Isoproterenol; D004837:Epinephrine; D010646:Phentolamine