Summary. Human neonates have been studied during the first hours of life. Blood glucose, portal plasma insulin and glucagon have been determined both at regular intervals up to 24 h after birth and during an intravenous glucose load performed at the 24th h. A material presenting the immunological characteristics of pancreatic glucagon has been found in the portal plasma of both normal infants and infants from diabetic mothers (IDM). The intravenous glucose load did not suppress plasma glucagon in the normal neonates nor in the IDM. Higher portal plasma glucagon values were observed in the late phase of the intravenous glucose load in normal neonates compared to IDM. Portal plasma insulin has been found higher in IDM both at the 24th h of life and during the early phase of the intravenous glucose tolerance test. The hypothesis is put forward that the behaviour difference in glueagon secretion might be a consequence of the relative hyperinsulinism of IDM with insulin facilitating the entry of glucose into the ~ cell thus permitting a more effective glucagon suppression. Prgscnce do glucagon pancrdatique dans le plasma portal do nouveau-ntis. Diffdrences de r~ponses de l'insuline et du g~ucagon au glucose entre los cnfants normaux et los enfants de m~res diabdtiques.Rd~umd. Los auteurs ont 4tudid des nouveau-ntis humains pendant los premi&res heures de la vie. La glye@mie, les taux d'insuline et de gincagon dans le plasma portal ont @t@ dosgs ~ intervalles r@guliers jusqu'~ la 246me heure apr6s la naissance, de mSme qub au cours d'une surcharge glueosde intraveineuse pratiqude ~ la 246me heure. --Un mat@riel prSsentant les caract@ristiques immunologiques du glucagon pancr@atique a @t@ misen @vidence dans le plasma portal des nouveau-ntis normaux et de mTre diab@tique. La surcharge glueosTe intraveineuse ne r@duit pas Ie taux de glucagon plasmatique chez le nouveau-n@ normal ni chez l'enfant de re@re diabdtique. --Dans la phase tardive de la surcharge glucosde intraveineuse, les valeurs de la glucagon@mie portale sent plus @levSes chez l'enfant normal que chez le nouveau-n4 de re@re diabdtique. L'insulin@mie portale est plus @levde chez le nouveau-n4 de mbre diabdtique ~ la 24brae heure de la vie et ~ la phase initiale de la surcharge glucosde. --L'hypothbse est proposde que la diffdrence de comportement du glucagon pourrait rdsulter de l'hyperinsulinisme relatif de l'enfant de mbre diabdtique, l'insuline favorisant la pdndtration de glucose darts la cellule aet permettant, par ee mSeanisme, une suppression plus effieace de la sdcrTtion de glucagon.
Glucose (1 gm/leg body weight) was administered intraportalIy to newborn infants, either alone or with intraportal insulin (0.1 or 0.3 U/Ieg body weight). As shown earlier, glucose alone did not suppress portal plasma glucagon; in contrast glucose plus insulin (at both doses used) resulted in a significant decrease in portal plasma glucagon. These data support the concept that insulin plays an important role in the physiologie sensitiveness of the alpha cell to glucose.
The effect of arginine infusion on the peripheral blood sugar, plasma insulin and plasma glucagon was studied in 28 appropriate-for-gestational-age premature newborn infants, 1-day-old, and in 12 normal children 4–10 years old. In the premature plasma insulin and glucagon concentrations increased after arginine though less noticeably than in the older children, and their insulin/glucagon molar ratio was low at fasting and did not change after arginine. It is assumed that the endocrine pancreatic activity is already developed at birth and adequate to the metabolic state in neonatal life.
Insulin secretion and glucose metabolism were studied during intravenous and oral glucose tolerance tests performed in one day and seven day old full-term and premature infants. Mean glucose disposal during the intravenous tests was more rapid in seven day old than in one day old infants.Insulin responses after intravenous glucose were characterized by higher insulin levels during the initial phase and lower levels during the second phase in both seven day old premature and full-term groups as compared with the patterns seen in one day < old infants. No differences in the mean values for blood glucose and plasma insulin were found among the four groups of infants at any time during the oral tests. DIABETES 23: 172-78, March, 1974. The low disposal rate of glucose administered intravenously in the newborn infant has been correlated with a reduced and delayed rate of insulin secretion. 1 " 6 However, it has been noticed that after the third day of life, the glucose assimilation coefficient (K t ) increases. 7 " 10 Since an increase in the pancreatic content and release of insulin in vivo (and in vitro in animals) has been observed in the immediate postnatal period, 1 1 ' 1 4 comparisons were made between insulin secretion in one day and seven day old full-term and premature infants. MATERIAL AND METHODSSubjects were 127 newborn infants: 36 one day old and 32 seven day old full-term infants and 27 one day old and 32 seven day old premature infants. Infants who were studied at one day of age were not restudied on the seventh day after birth, but groups of different infants were used. The mean birth weight of the fullterm infants was 3.41 kg. (range 2.96 to 4.05 kg.), and gestational age ranged from thirty-eight to forty weeks. The premature infants had a mean birth weight of 2.02 kg. (range 1.79 to 2.52 kg.), and their gestational age ranged from thirty-one to thirty-six weeks. The mean body weights were similar in the groups of premature infants. The tests were performed on the first day of life before any oral or intravenous feedings were started and, on the seventh day, on infants who had fasted for six hours. Infants of diabetic mothers, infants with hemolytic disease or other serious disorders and infants small for gestational age were not included in this study.Glucose tolerance was assessed with both intravenous and oral glucose tests. Intravenous glucose tolerance tests (IVGTT) were performed by rapid injection of glucose (1 gm./l kg. body weight/30 sec). The IVGTT was performed in 26 one day old full-term infants, 22 seven day old full-term infants, 15 one day old premature infants and 20 seven day old premature infants. Specimens of blood were taken at 0, 1, 3, 5, 10, 20, 30, 40, 60 and 90 minutes during the test for glucose and insulin determinations. Oral glucose tolerance tests (OGTT) were performed by administration of glucose in a dose of 2. 5 gm./l kg. body weight using a 40 per cent solution via nasogastric tube. The OGTT was performed in 10 one day old full-term infants, 10 seven day old full-te...
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