The post-natal development of hepatic fructokinase

Dg, Walker

doi:10.1042/bj0870576

Cited by 41 publications

(12 citation statements)

References 12 publications

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“…In suckling rats adaptive changes in enzyme activity in keeping with this postulate have been demon strated [2,16] and have been shown to be similar to changes found in adult rats fed a high fat diet or subjected to starvation [15].…”

mentioning

confidence: 98%

Metabolism of Subcutaneous Adipose Tissue in the Immediate Postnatal Period of Human Newborns

Novák¹,

Hahn²,

Penn³

et al. 1973

Neonatology

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The activities of citrate cleavage enzyme (CCE; EC 4.1.3.8), malic enzyme (ME; EC 1.1.1.40), phosphoenol pyruvate carboxykinase (PEPK; EC 2.7.1.40), α-glycerophosphate dehydrogenase (GPD EC 1.1.1.8) and glucose-6-phosphate dehydrogenase (G-6-PD; EC 1.1.1.49) was measured in cytosol of subcutaneous adipose (white) tissue in human new borns and adults. ME activity was highest during the first day of life and then decreased. CCE was higher in the newborn adipose tissue than in adults. G-6-PD and GPD activities were higher in the neonate. No changes were noted with PEPK. Our results obtained on activities of enzymes involved in citrate breakdown (CCE) providing acetylCoA and furnishing ‘reduction potential’ for fatiy acid synthesis (ME, G-6-PD) suggest that fatty acid synthesis decreases rapidly after birth. This decrease in enzymes involved in fatty acid synthesis is faster than the decrease in enzymes involved in glycerol production

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mentioning

confidence: 98%

Metabolism of Subcutaneous Adipose Tissue in the Immediate Postnatal Period of Human Newborns

Novák¹,

Hahn²,

Penn³

et al. 1973

Neonatology

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“…In fetal tissue it is completely absent [Walker, 1963;Ballard and Olivier, 1964], According to our investigations, ketohexokinase can be found in bovine lenses of about 2 years of age. Therefore, it is probable that a fructose breakdown takes place by this pathway.…”

Section: Discussionmentioning

confidence: 99%

“…The activity of hexokinase is low and its affinity for fructose (KM = 2 x 10-3 M) is smaller than that for glucose (KM = 1CF4 M) [Walker, 1963]. The Michaelis constant of ketohexokinase is KM = 4 x 1(H M for fructose [Adelman et a i, 1967], so that in this tissue F-l-P is likely to be the initial product for fructose utilization.…”

Section: (3)mentioning

confidence: 99%

Presence of Ketohexokinase EC 2.7.1.3 in Bovine Lenses

Ohrloff¹,

Hockwin²

1973

Ophthalmic Res

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“…Schapira, Schapira, and Dreyfus have reported recently on diminished fructose aldolase activity in a few human fetal liver samples (22). WValker has found absent or diminished hepatic frtictokinase in three nonfructogenic species in the first 7 to 10 days after birth (23). He also showed a diminished fructose disappearance rate from the blood of the newborn rabbit, which had decreased enzyme activity in the liver.…”

Section: Discussionmentioning

confidence: 99%

Transient Intolerance to Exogenous Fructose in the Newborn *

Schwartz¹,

Gamsu²,

Mulligan³

et al. 1964

J. Clin. Invest.

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The normal newborn infant has inadequate homeostatic mechanisms for stabilizing the concentration of glucose in the blood (1, 2). Recent studies of carbohydrate metabolism in this age group have indicated a diminished responsiveness to small doses (30 jug per kg body weight) of exogenous glucagon (3, 4) and a slow rate of disappearance from the blood of either glucose or galactose administered intravenously (4, 5). Similar results have been observed in the premature infant (6). Glucose uptake by the tissues improves with a second dose and with age. The newborn infant is sensitive to exogenous insulin (5, 6), and insulin-like substances have been found in umbilical vein blood (7). We interpret the effects of the injection of either glucagon or galactose, which resulted in a prompt rise in the concentration of glucose in the blood, to indicate functional adequacy of the enzymes of the glycogen cycle in the liver of the newborn infant.Since the pathway for fructose metabolism in the liver differs from that of galactose or glucose, we wished to evaluate the effect of a rapid infusion of fructose on the concentration of glucose and lactate in the blood of newborn infants. The possible mechanisms involved are elucidated by combining the effects of epinephrine plus glucagon or galactose and fructose infusions. MethodsSixty-one normal, newborn, full-term infants were studied after uncomplicated vaginal deliveries. Seventeen infants were born at the Cleveland Metropolitan General Hospital, the remaining forty-four at the University of Illinois, Research and Education Hospitals.All infants were fasted for 12 hours and given glucose water for 12 hours and then dilute formula, 15 cal per 30 ml, for 24 to 72 hours-routine newborn care. Infants less than 6 hours of age were fasted from the time of delivery. Infants between 6 and 24 hours of age were fasted variable times from a minimum of 3 hours after a glucose feeding to a maximum of 12 hours after delivery. Infants older than 24 hours were fasted 3 to 4 hours before study. All infants tolerated the procedures well, showing no marked alterations in temperature, nor any circulatory, respiratory, or neurological abnormalities. The responses to fructose in these infants were measured after a rapid injection of 25%o fructose (1 g per kg body weight) given within a 2-to 4-minute period into a peripheral vein. Blood samples were obtained from punctures of the skin of the unwarmed heel. After 0.2-ml control samples were obtained before any injection, further samples were taken at 5,10,20, 30, 45, 60, 75, 90, and 120 minutes after injection. To prevent glycolysis the capillary blood samples were either precipitated immediately with barium hydroxide and zinc sulfate or transferred to sodium fluoride solutions (0.6 mg per tube). Separate 0.1-ml samples were precipitated directly with trichloroacetic acid for the lactic acid determinations.The infants were grouped according to age and test, as indicated in Table I. Group I infants received fructose only. Group II infants were given 3...

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The post-natal development of hepatic fructokinase

Cited by 41 publications

References 12 publications

Metabolism of Subcutaneous Adipose Tissue in the Immediate Postnatal Period of Human Newborns

Metabolism of Subcutaneous Adipose Tissue in the Immediate Postnatal Period of Human Newborns

Presence of Ketohexokinase EC 2.7.1.3 in Bovine Lenses

Transient Intolerance to Exogenous Fructose in the Newborn *

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