Glucose Production and Utilization in the Newborn Puppy

Kornhauser, David M.; Adam, Peter A. J.; Schwartz, Robert

doi:10.1203/00006450-197003000-00002

Cited by 30 publications

(10 citation statements)

References 9 publications

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“…cell to respond to glucose, since no response was noted in the pancreas of fed animals delivered one day before term, whereas a good response was noted in the pancreas of full-term pups, even when they had not been fed. This finding is in agreement with the observations that glucose causes little or no increase of plasma IRI in premature human babies 31 ' 32 and in newborn puppies 33 and a delayed response in normalterm babies 34 and that glucose-stimulated insulin release in fetal explants of rat pancreas does not occur, unless an inhibitor of phosphodiesterase activity is added to the incubation media. 28 The enhancement of /?-cell reactivity by feeding may be due to a direct effect on the /?…”

Section: Discussionsupporting

confidence: 92%

Effects of Gestational Age, Birth and Feeding on the Insulinogenic Response to Glucose and Tolbutamide by Fetal and Newborn Rat Pancreas

1971

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Perinatal maturation of the pancreatic beta cells was studied in the rat. Insulin synthesis proceeded rapidly between the twentieth gestational day and the third postnatal day. The insulin concentration in the pancreas and the amount of insulin available per gram of body weight reached a maximum sixty hours after birth and then decreased slowly toward the values observed in the adult rat. The pancreatic beta cells became responsive to glucose and to tolbutamide during the twenty-third day after fertilization. This phenomenon seemed to be related to the gestational age and not to act of birth or to feeding, although feeding appeared to increase the insulinogenic response to glucose. DIABETES 20: 586-91, September, 1971. The fetal pancreas synthesizes proinsulin and converts it into insulin. 1 ' 2 The embryologic age at which insulin is found, however, depends upon the sensitivity of the methods used for its detection. Thus, the presence of the hormone has been demonstrated in the pancreas of seventeen or eighteen-day-old rat fetus by histologic and histochemical means, 3 ' 4 in that of fourteen-day-old fetus by means of a bioassay 5 and in that of eleven-day-old

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Section: Discussionsupporting

confidence: 92%

Effects of Gestational Age, Birth and Feeding on the Insulinogenic Response to Glucose and Tolbutamide by Fetal and Newborn Rat Pancreas

1971

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“…This elevated level of endogenous glucose production in the neonate (in contrast to the adult) has previously been shown in the puppy by Kornhauser et al (13), in the term rhesus monkey newborn by Sherwood et al (17), and in the human by Bier et al (2). In contrast, the 4-to 5-month-old sheep evidenced an endogenous glucose production of 2.8 f 0.2 mg/kg/min which is comparable to values noted for the adult dog by Steele (20) and for man by Madison (16).…”

Section: Cowett E T a Lmentioning

confidence: 76%

Endogenous Glucose Production during Constant Glucose Infusion in the Newborn Lamb

Cowett

Susa

et al. 1978

Pediatr Res

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SummaryPrompt diminution of endogenous hepatic glucose production is characteristic of the mature (adult) response to exogenous glucose infusion. We have tested the validity of this hypothesis in the neonatal period in 26 unanesthetized mixed breed term lambs and for comparison in eight 4-to 5-month-old mixed breed sheep. After a 7-hr fast, basal plasma glucose, insulin, and glucagon concentrations were determined following which the term lambs received either no glucose or 5.7, 11.7, or 21.7 mg glucose/kg/min over a wriod of 6 hr. and the 5-month-old s h e e~ received either none or 5.7 mg glucose/kg/min. Glucose turnover was determined by the prime-constant infusion technique of Steele using 3H6 radiolabeled glucose during a 50-min turnover period which followed the 6-hr infusion of 0.45% saline or varying doses of glucose following the onset of fasting by 14 hr. Both newborn and adult animals maintained a constant plasma glucose concentration and glucose specific activity during the turnover period. Endogenous glucose production persisted in the term lamb until the exogenous glucose infusion reached the rate of 21.7 mg/kg/min. In contrast, the adult lambs reduced their endogenous glucose production with an esogenous glucose infusion rate of 5.7 mg/kg/min. At the time the endogenous glucose production rates were significantly reduced, the plasma insulin level in the newborn lamb was 5-fold greater than that of the adult sheep.Under steady state conditions of plasma glucose concentration and glucose specific activity, our data suggest that there is imprecise control of endogenous glucose production in the newborn lamb in contrast to the older sheep of 4-5 months of age. The absence of precise control may be due to decreased hepatic sensitivity for insulin.In the adult, when glucose is infused at a rate equal to or greater than endogenous glucose output, endogenous gl&ose pro&ction will be curtailed promptly as a result of precise hepatic control of glucose homeostasis (5, i5, 16, 18). If ihe glucos'e infusion rate and decreased hepatic output are balanced and peripheral utilization remains unchanged, plasma glucose concentration will be constant.Varma et al. (21) infused the newborn pup and adult dog with glucose estimated to be equal to or greater than the endogenous glucose production rate. The newborn pup failed to diminish endogenous glucose production and attain an equilibrium (steady state), but rather evidenced a rise in plasma glucose concentration over the 2-hr duration of the study with a nonsteady state. The adult, in contrast, reversed a n initial rise in plasma glucose concentration and established a new equilibrium within 90 min of exogenous glucose infusion. It was speculated that this difference in neonatal and adult responses to exogenous glucose infusion was due to decreased tissue insulin sensitivity in the neonatal subjects.T o explore this hypothesis, varying concentrations of glucose were infused constantly in a newborn or young adult sheep for a sufficient time to produce a stable equilib...

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“…It would be difficult to extrapolate and compare our data across species. Nonetheless, glucose produc tion and utilization are also comparable in human neonates and in newborn dogs [18]. Thus, while demonstrating that the neonatal canine brain can utilize 36.6% of systemic glucose produced, peripheral tissues appear to consume a greater portion of glucose turn over.…”

Section: Discussionmentioning

confidence: 91%

Partitioning and Extraction of Glucose Regulates Cerebral Glucose Utilization in Newborn Dogs

Huang¹,

Kliegman²,

Chau³

1989

Neonatology

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We investigated the amount of fasting steady-state systemic glucose production utilized by the neonatal canine cerebral cortex. The relationship of systemic glucose production and cerebral glucose utilization were analyzed as functions of cerebral blood flow, cerebral oxygen uptake, and indirect measures of alternate fuel utilization. Fasting arterial blood glucose was 3.36 mM and glucose production was 49.6 μmol/kg/min. Average cerebral blood flow was 0.83 ml/g/min, and cerebral glucose uptake was 0.60 ± 0.15 μmol/g/min. 36.6% of systemic glucose production was utilized by the cerebral cortex. There were no correlations between systemic glucose production, cerebral blood flow, or cerebral glucose uptake with blood glucose concentration. Furthermore, total cerebral glucose uptake was static across a wide range of glucose levels. Nonetheless, the percent of glucose production used by the brain was an inverse function of systemic glucose production (r = ––0.71, p < 0.001). The cerebral extraction of glucose (27.6 ± 4.1 %) decreased as a function of increasing blood glucose levels (r = ––0.51, p < 0.05), while brain uptake index correlated with increasing systemic glucose production (r = 0.61, p < 0.02). We can conclude that the canine neonatal cerebral cortex may utilize only 37% of systemic glucose production. At low rates of glucose turnover, a larger proportion of systemic glucose production is allotted to the brain. Mechanisms that may regulate total cerebral glucose influx may be glucose permeability, or the increased extraction of glucose at lower blood glucose levels.

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Glucose Production and Utilization in the Newborn Puppy

Cited by 30 publications

References 9 publications

Effects of Gestational Age, Birth and Feeding on the Insulinogenic Response to Glucose and Tolbutamide by Fetal and Newborn Rat Pancreas

Effects of Gestational Age, Birth and Feeding on the Insulinogenic Response to Glucose and Tolbutamide by Fetal and Newborn Rat Pancreas

Endogenous Glucose Production during Constant Glucose Infusion in the Newborn Lamb

Partitioning and Extraction of Glucose Regulates Cerebral Glucose Utilization in Newborn Dogs

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