Umbilical arterial blood glucose concentration, pH, base deficit and blood gases in preterm, growth retarded and normal infants

Umbilical glucose and lactate extractions were determined in previously instrumented pregnant ewes into some of which D-glucose was infused to produce graded levels of maternal hyperglycemia as great as 20 mM. While fetal arterial glucose concentration continued to increase linearly as a function of maternal arterial glucose concentration during maternal hyperglycemia, the umbilical venoarterial difference in blood glucose concentration did not, and umbilical glucose extraction approached a plateau at approximately 0.063 mmol X min-1 X kg fetus-1 at maternal glucose concentrations greater than approximately 8 mM. The observed plateau in glucose extraction is consistent with saturation at high maternal glucose concentrations of the carrier mechanism for transport of glucose from the maternal to the fetal aspects of the trophoblast. The observed value of the plateau in umbilical extraction of glucose is slightly less than the maximum extraction predicted from previously published equations for this species, but the maternal blood glucose concentration at which the observed maximum occurred agrees closely with the value predicted by those equations. Umbilical lactate extraction, 0.031 +/- 0.021 mmol X min-1 X kg fetus-1, was independent of maternal arterial blood glucose and lactate concentrations and was independent of umbilical glucose extraction.

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The effect of acetoacetate on plasma insulin concentration

Biochemical Journal ◽

10.1042/bj1250541 ◽

1971 ◽

Vol 125 (2) ◽

pp. 541-544 ◽

Cited By ~ 31

Author(s):

R. A. Hawkins ◽

K. G. M. M. Alberti ◽

C. R. S. Houghton ◽

D. H. Williamson ◽

H. A. Krebs

Keyword(s):

Fatty Acids ◽

Blood Glucose ◽

Free Fatty Acids ◽

Glucose Concentration ◽

Plasma Insulin ◽

Blood Glucose Concentration ◽

Diabetic Rats ◽

Insulin Concentration ◽

Plasma Insulin Concentration ◽

Arterial Blood

1. Sodium acetoacetate was infused into the inferior vena cava of fed rats, 48h-starved rats, and fed streptozotocin-diabetic rats treated with insulin. Arterial blood was obtained from a femoral artery catheter. 2. Acetoacetate infusion caused a fall in blood glucose concentration in fed rats from 6.16 to 5.11mm in 1h, whereas no change occurred in starved or fed–diabetic rats. 3. Plasma free fatty acids decreased within 10min, from 0.82 to 0.64mequiv./l in fed rats, 1.16 to 0.79mequiv./l in starved rats and 0.83 to 0.65mequiv./l in fed–diabetic rats. 4. At 10min the plasma concentration rose from 20 to 49.9μunits/ml in fed unanaesthetized rats and from 6.4 to 18.5μunits/ml in starved rats. There was no change in insulin concentration in the diabetic rats. 5. Nembutal-anaesthetized fed rats had a more marked increase in plasma insulin concentration, from 30 to 101μunits/ml within 10min. 6. A fall in blood glucose concentration in fed rats and a decrease in free fatty acids in both fed and starved rats is to be expected as a consequence of the increase in plasma insulin. 7. The fall in the concentration of free fatty acids in diabetic rats may be due to a direct effect of ketone bodies on adipose tissue. A similar effect on free fatty acids could also be operative in normal fed or starved rats.

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The effect of insulin-induced hypoglycaemia on gastrointestinal motility in man

Clinical Science ◽

10.1042/cs0720743 ◽

1987 ◽

Vol 72 (6) ◽

pp. 743-748 ◽

Cited By ~ 2

Author(s):

I. W. Fellows ◽

D. F. Evans ◽

T. Bennett ◽

I. A. Macdonald ◽

A. G. Clark ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Blood Glucose ◽

Motor Activity ◽

Arterial Blood Pressure ◽

Pancreatic Polypeptide ◽

Glucose Concentration ◽

Blood Glucose Concentration ◽

Arterial Blood ◽

Median Interval

1. The effect of insulin-induced hypoglycaemia on gastro-jejunal motility was studied in five, healthy, male subjects using tethered, pressure sensitive, radiotelemetry capsules. 2. Thirty minutes after the intravenous injection of soluble insulin (0.15 unit/kg body weight), a significant reduction in blood glucose concentration (control: 5.26 ± 0.19 sem mmol/l; insulin: 1.48 ± 0.44 mmol/l; P < 0.001) was associated with a rise in heart rate (mean peak rise 29 ± 8 beats/min, P < 0.05), systolic arterial blood pressure (mean peak rise 28 ± 4 mmHg, P < 0.01) and plasma pancreatic polypeptide concentration (control: 20 ± 7 pmol/l; insulin: 287 ± 66 pmol/l; P < 0.01). These events coincided with a short period of jejunal motor activity, which was not associated with gastric motor activity nor with raised plasma motilin concentrations. 3. During the control study, there were no changes in blood glucose concentration, heart rate, arterial blood pressure or plasma pancreatic polypeptide concentrations, and there was no jejunal motor activity. 4. The interval between successive gastric migrating motor complexes (MMC) was not significantly different in the insulin and control studies (control: median interval 110 min, range 108–148 min; insulin: median interval 124 min, range 115–125 min), suggesting that the fasting gastro-jejunal MMC and jejunal motor activity arose independently. 5. Insulin-induced hypoglycaemia is accompanied by jejunal motor activity, which may underlie the abdominal symptoms associated with hypoglycaemia.

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Effects of dietary manipulations and glucose infusion on glucagon response during exercise in rats

Journal of Applied Physiology ◽

10.1152/jappl.1997.83.1.148 ◽

1997 ◽

Vol 83 (1) ◽

pp. 148-152 ◽

Cited By ~ 5

Author(s):

Maurice Tadjoré ◽

Raynald Bergeron ◽

Martin Latour ◽

François Désy ◽

Claude Warren ◽

...

Keyword(s):

Blood Glucose ◽

Plasma Glucose ◽

Glucose Concentration ◽

Blood Glucose Concentration ◽

Glucose Infusion ◽

Glucose Response ◽

Glucose Levels ◽

Arterial Blood ◽

Blood Glucose Levels ◽

Exercise Period

Tadjoré, Maurice, Raynald Bergeron, Martin Latour, François Désy, Claude Warren, and Jean-Marc Lavoie.Effects of dietary manipulations and glucose infusion on glucagon response during exercise in rats. J. Appl. Physiol. 83(1): 148–152, 1997.—The purpose of the present investigation was to test the hypothesis that blood glucose concentration is not always related to glucagon response during exercise. Three groups of rats were submitted to a prolonged (3-h) swimming exercise. Two groups of rats had their normal food intake restricted by 50% the night before the experiment. One of these two groups of rats was intravenously infused with glucose throughout exercise to maintain euglycemia. The third group of rats swam while under normal dietary conditions. Plasma glucose, sampled in arterial blood, was reduced ( P < 0.05) at 75, 105, 150, and 170 min of exercise (from ∼130 to 110 mg/dl) in the food-restricted animals without glucose infusion, whereas a significant ( P < 0.05) increase was measured in the two other groups during exercise. A significant ( P < 0.01) difference in the mean integrated areas under the glucose-concentration curve was found only between the fed and the two food-restricted groups. Plasma insulin concentrations decreased ( P < 0.05) similarly in all groups during exercise, whereas plasma epinephrine and norepinephrine concentrations increased significantly ( P < 0.01) in all groups. Despite differences between groups in plasma glucose response during exercise, and despite the absence of any decrease in exercising blood glucose levels in at least two of the three groups, plasma glucagon responses were increased ( P < 0.05) similarly in all groups (from ∼250 to 550 pg/ml) at the end of the exercise period. The increase in glucagon was significant after 90 min of exercise in the food-restricted groups, with or without glucose infusion, but only after 140 min in the fed group. These results indicate that the glucagon response during exercise is not always linked to the decrease in plasma glucose.

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Blood pressure and cardiovascular reflex development in fetal sheep. Relation to hypoxaemia, weight, and blood glucose

Reproduction Fertility and Development ◽

10.1071/rd9950553 ◽

1995 ◽

Vol 7 (3) ◽

pp. 553 ◽

Cited By ~ 19

Author(s):

C Crowe ◽

L Bennet ◽

MA Hanson

Keyword(s):

Blood Pressure ◽

Blood Glucose ◽

Blood Glucose Concentration ◽

Lactate Concentration ◽

Blood Gases ◽

Late Gestation ◽

Fetal Sheep ◽

Arterial Blood ◽

The Right ◽

Arterial O2 Saturation

We measured mean arterial blood pressure (MAP), fetal heart rate (FHR), the baroreflex, weight, blood gases, blood glucose and lactate in chronically instrumented fetal sheep for 14 days from Day 105 to Day 109 gestation, with or without daily administration of 1 h of acute isocapnic hypoxaemia (arterial O2 partial pressure, PaO2, 11-13 mm Hg; 1 mm Hg = 133 Pa). Fetuses subjected to hypoxia showed no significant differences in MAP or FHR v. control fetuses. However, examination of all fetuses together revealed that there were two distinct groups: those showing a rise in MAP over the 14 days ('pressure up' group, PU), and those in which blood pressure did not increase or showed only a slight decrease ('pressure down' group, PD). PU fetuses were proportionately larger than PD fetuses. In contrast to PU fetuses, PD fetuses had lower blood glucose concentration, arterial O2 saturation (SaO2), PaO2, total haemoglobin, haematocrit and oxygen content, and higher lactate concentration, pH and PaCO2. PU fetuses showed a shift of the baroreflex MAP/R-R interval curve to the right, however, the PD group showed a shift upwards from Day 1 to Day 14. The PD group responded to hypoxia with a greater increase in MAP than the PU group. Thus, repeated acute moderate isocapnic hypoxia does not affect development of MAP or FHR in late gestation fetal sheep. However, MAP follows different trajectories in individual fetuses, related to fetal size and the availability of oxygen and/or glucose. Cardiovascular chemoreflexes and baroreflexes are also different, depending on the MAP trajectory. These data indicate an important association between growth and blood pressure development, and also show that differences in growth are associated with changes in cardiovascular control.

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