Gastric secretion, continuously recorded blood sugar, and plasma steroids after insulin

¹ Department of Neurosurgery and Department of Physiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania

Gastric secretory response to insulin hypoglycemia (1.5 U/kg) was studied in ten experiments in four beagle dogs fitted with gastric fistulas. Blood sugar reduction was recorded continuously by means of an autoanalyzer. Plasma steroid concentrations were measured at hourly intervals. In seven of ten experiments gastric acid output was maximum 30–60 min after insulin was given. The onset of gastric secretion occurred 30–35 min after insulin, and the nadir of the blood sugar occurred 37 ± 4 min after insulin. Biphasic responses were seen only in two experiments. There was a delay of 13 ± 2 min before hypoglycemia began. The mean value of the lowest blood sugar was 28 ± 2 mg/100 ml. Plasma hydrocortisone concentrations increased to maximum values at 2 hr and then fell to control levels within 6 hr. In most experiments gastric secretion decreased as blood sugar levels returned to fasting values. Late phases could not be correlated with hypoglycemia or elevated plasma steroid concentrations.