EFFECT OF SOMATOSTATIN INFUSION ON INTERMEDIARY METABOLISM AND ENTERO-INSULAR HORMONE RELEASE IN INFANTS WITH HYPERINSULINAEMIC HYPOGLYCAEMIA

Abstract. Aynsley-Green, A., Barnes, N. D., Adrian, T. E., Kingston, J., Boyes, S., and Bloom, S. R. (University Department of Paediatrics, John Radcliffe Hospital, Oxford, Department of Paediatrics, New Addenbrookes Hospital, Cambridge, and Department of Medicine, Hammersmith Hospital, London, England). Effect of somatostatin infusion on intermediary metabolism and enteroinsular hormone release in infants with hyperinsulinaemic hypoglycaemia. Acta Paediatr Scand, 70: 889, 1981.-The hypoglycaemia of infantile hyper-insulinism is often exceedingly difficult to control. The use of somatostatin has been advocated recently in such infants because of its effect on inhibiting insulin release, but nothing is known of the wider effects of this potent hormone in the young child. Two infants presenting at 9 weeks and 5 days of age with severe hyperinsulinaemic hypoglycaemia were studied during an infusion of somatostatin. In both infants normoglycaemia was restored with suppression of insulin secretion. An increase in blood ketone bodies occurred, but no change was seen in blood pyruvate, lactate or alanine concentrations. The plasma concentrations of glucagon, Cortisol, growth hormone, motilin.-pancreatic polypeptide, gastric inhibitory polypeptide, neurotensin, gastrin and vasoactive intestinal peptide decreased markedly during the somatostatin infusion. No consistent change occurred in plasma enteroglucagon or secretin values. We conclude that somatostatin effectively suppresses abnormal insulin secretion in infants, but it has profound effects on the release of nine other hormones. Further studies are needed to define the consequences of suppressing the release of these hormones before somatostatin can be used routinely in the management of infantile hyperinsulinism.     

METABOLIC AND ENDOCRINE RESPONSES TO A MILK FEED IN SIX-DAY-OLD TERM INFANTS: DIFFERENCES BETWEEN BREAST AND COW'S MILK FORMULA FEEDING

ABSTRACT. Lucas, A., Boyes, S., Aynsley-Green, A. (Department of Paediatrics, John Radcliffe Hospital, Oxford) and Bloom, S. R. (Hammersmith Hospital, London, England). Metabolic and endocrine responses to a milk feed in six-day-old term infants: JMfferences between breast and cow's milk formula feeding. Acta Paediatr Scand, 70:195, 1981. – There is little information on the metabolic and endocrine responses to milk feeding in the neonatal period particularly in relation to the mode of nutrition and composition of the milk. Plasma concentrations of insulin, glucagon and gastric inhibitory polypeptide (GIP) together with blood levels of glucose, ketone bodies, pyruvate, lactate and glycerol were measured pre- and post-prandially in 79 healthy six-day-old term infants who had been either breast fed or fed on a modified cow's milk formula (Cow and Gate Premium) from birth. Formula fed infants had a greater insulin and GIP response to feeding and their basal and postprandial blood ketones were considerably lower than in breast fed infants. In addition a significantly greater post feed rise in both lactate and pyruvate concentrations was observed with formula feeding. These results may have significant implications regarding infant feeding and postnatal metabolism.     

EFFECT OF INTRAVENOUS L-ALANINE ADMINISTRATION ON PLASMA GLUCOSE, INSULIN AND GLUCAGON, BLOOD PYRUVATE, LACTATE AND BETA-HYDROXYBUTYRATE CONCENTRATIONS IN NEWBORN INFANTS Study in Term and Preterm Newborn Infants

ABSTRACT. Ten term and eleven preterm newborn infants with appropriate weights for their gestational age were infused for one minute with L-alanine (150 mg/kg) at the age of 29 to 76 hours (mean 48 hours) and circulating levels of glucose, lactate, pyruvate, d -betahydroxybutyrate ( d -BOHB), insulin and glucagon were monitored. Plasma glucose concentrations increased from 2.7±0.16 (mean±S.E.M.) to 3.7±0.2 mmol/1 after 50 min (p±0.01) in term infants. In preterm infants, after an initial decrease of the glucose level from 3.1±0.16 to 2.6±0.16 mmol/1 (p±0.05), it returned to the baseline level at 50 min: 3.0±0.2 mmol/1. The blood concentration of d -BOHB decreased in term infants from 192±37 to 112±6 μM/1 (p±0.01) after 40 min. In preterms, its decrease was not significant (p±0.05). Plasma glucagon levels rose from 53±5 to 70±8 pmol/1 after ten minutes (p±0.01) in term infants and from 61±6 to 75±9 after 20 min (p±0.01) in preterm infants. There were no significant changes in plasma insulin concentrations in either group. Forty minutes after l -alanine infusion, I/G ratios were lower in preterm infants (1.26±0.14) than in term infants (1.71±0.25) (p±0.01). There was no relationship between the glycemic responses to l -alanine and the basal levels of d -BOHB.
The data suggest that the glycemic effect of l -alanine infusion and circulating glucagon depends upon a specific stage in maturation. The antiketogenic effect of l -alanine infusion is observed in term infants as in adults.     

THE EFFECT OF FEEDS OF DIFFERING COMPOSITION ON ENTERO-INSULAR HORMONE SECRETION IN THE FIRST HOURS OF LIFE IN HUMAN NEONATES

Abstract. Little is known on the enteral stimuli for gastro-intestinal hormone release in newborn infants. We have compared the effect of the first feed of human breast milk (5 ml/kg) or 10% dextrose (5 ml/kg) on blood glucose and plasma gastrin, enteroglucagon, Gastric Inhibitory polypeptide (GIP), pancreatic glucagon, and insulin in 21 full-term infants at 4–6 hours of age. The first feed of human milk caused a rise in blood glucose and plasma insulin, gastrin and enteroglucagon, but no change occurred in GIP or pancreatic glucagon. The 10% dextrose feed did not stimulate enteroglucagon release, although similar changes occurred in blood glucose and plasma insulin and gastrin. We conclude that the composition of the feed influences the pattern of gastro-intestinal hormone release during the first hours of life and that the entero-insular responses to feeding differ in the neonate and the adult.     

CEREBRAL BLOOD FLOW AND EXCHANGE OF OXYGEN, GLUCOSE, KETONE BODIES, LACTATE, PYRUVATE AND AMINO ACIDS IN INFANTS

Abstract. Cerebral blood flow (CBF) and cerebral av-differences of oxygen and circulating substrates were measured in normocapnic infants during general anaesthesia before elective surgery in order to study possible age-dependent variations. CBF was determined by a minor modification of the Kety-Schmidt technique from desaturation curves of nitrous oxide (N₂O) in arterial and cerebral venous blood (N₂O analysed by gas chromatography on 15 μl blood samples) after reduction of inhaled N₂O from 75 to 50%. The reproducibility was ±4.6%. Lactate, pyruvate and oxygen were determined in whole blood and amino acids in plasma by ion-exchange chromatography. Reliable av-differences of glucose, acetoacetate and d -β-hydroxybutyrate could be calculated from plasma values and hematocrits. Mean values from 12 infants (age II days-12 months) were: CBF 69 ml/100 g · min^-1; cerebral uptake (in μmoles/100 g · min^-1): oxygen 104, glucose 27, acetoacetate 0.9, d -β-hydroxybutyrate 2.3; cerebral release: lactate 2.4 and pyruvate 0.8. Significant uptake of amino acids was found only for histidine 0.95 and arginine 0.7. Significant correlations between arterial concentration and cerebral exchange were found for: ornithine, arginine, phenylalanine, aspartic acid, serine, glutamine and acetoacetate. CBF and substrate exchange were unrelated to age within the group. Infants had higher mean CBF and greater uptake of ketone bodies than has been reported in adults.