HUMAN PLACENTAL LACTOGEN CONCENTRATION DURING PHYSIOLOGICAL FLUCTUATIONS OF SERUM GLUCOSE IN NORMAL PREGNANT AND GESTATIONAL DIABETIC WOMEN

1975 ◽  
Vol 80 (2) ◽  
pp. 365-373 ◽  
Author(s):  
C. Kühl ◽  
P. Gæde ◽  
J. G. Klebe ◽  
J. Pedersen

ABSTRACT Oral glucose tolerance tests (OGTT) were carried out in 9 normal pregnant women and 11 non-obese gestational diabetics in late pregnancy. All samples were analysed for the content of glucose, insulin and placental lactogen hormone (HPL). Furthermore, spontaneous changes in the serum HPL concentration during a 3 h period were studied in 6 normal women in the 2nd half of pregnancy. During OGTT only small and insignificant changes in the level of HPL were observed in both the normal subjects and the gestational diabetics. Furthermore, the mean HPL concentration curves of the normal subjects and the gestational diabetics were superimposed although the mean glucose concentration curves were significantly different. The study of spontaneous changes in HPL revealed only small and insignificant fluctuations in the serum HPL level, and the mean concentration curve resembled those obtained from the OGTT-study. It is concluded that neither the absolute serum glucose level, nor physiological fluctuations in the serum glucose concentration seemed to influence the serum concentration of HPL in this type of patients.

1975 ◽  
Vol 79 (4) ◽  
pp. 709-719 ◽  
Author(s):  
C. Kühl

ABSTRACT Glucose and insulin concentrations during basal fasting conditions and after an oral challenge with glucose have been studied during early, mid and late pregnancy and also after delivery in a group of 9 normal women. No significant changes in the fasting serum glucose concentration was observed during pregnancy. In contrast the fasting serum insulin gradually increased. No changes in the mean glucose concentration curve were observed until the second half of pregnancy where the level of the curve was significantly elevated, but statistically calculated limits of normality derived from a special study of non-pregnant normal controls were not exceeded. The serum insulin response to glucose was significantly increased at all stages of gestation and in parallel the insulin-to-glucose index calculated for the total areas below the insulin and glucose concentration curves increased significantly. The fasting insulin-to-glucose index also increased and was found to be significantly correlated to the stage of gestation. The shape of the glucose and insulin curves was modified in the opposite direction by pregnancy: the peak value of glucose was delayed whereas that of insulin was advanced. The results indicate that in pregnancy a diminished 'peripheral sensitivity' to endogenous insulin apparently develops. As it can be seen both in the basal fasting state and after challenge with glucose a permanent influence of pregnancy on serum insulin secretion seems most likely. Therefore, the possible involvement of the hormones of pregnancy should first be considered as a cause of these findings. However, different factors, e. g. altered levels of pro-insulin or glucagon, might also be involved in the mechanism.


1982 ◽  
Vol 28 (12) ◽  
pp. 2405-2407 ◽  
Author(s):  
O Giampietro ◽  
A Pilo ◽  
G Buzzigoli ◽  
C Boni ◽  
R Navalesi

Abstract Glucose was measured by the ferricyanide, the Beckman glucose oxidase, and the hexokinase procedures in 228 plasma samples taken during standard oral glucose-tolerance tests in 17 normal subjects and in 21 chemical diabetics. The neocuproine method was also used to measure glucose concentration in 156 samples (78 before and 78 after dialysis) collected from six diabetic and uremic patients who were on maintenance hemodialysis. Ferricyanide in all conditions and neocuproine in uremic patients overestimated glucose concentrations over the entire experimental range as compared with either enzymic method. This bias or systematic error of the reducing vs the enzymic procedures, due to nonglucose reducing substances ("saccharoids"), becomes considerably greater when their concentration is increased as in chronic uremia. Also, the inverse relation between glucose concentration and overestimation of glucose by the reducing methods has been detected. With respect to the hexokinase method, a mild but significant underestimate of glucose oxidase readings has been observed for higher glucose concentrations. We find neocuproine to be the most imprecise of these procedures.


1969 ◽  
Vol 60 (4) ◽  
pp. 579-585
Author(s):  
K. Schollberg ◽  
E. Seiler ◽  
J. Holtorff

ABSTRACT The urinary excretion of testosterone and epitestosterone by women in late pregnancy has been studied. The mean values of 22 normal women in pregnancy mens X are 12.9 ± 9.2 μg/24 h in the case of testosterone and 16.1 ± 16.2 μg/24 h in the case of epitestosterone. Both values do not differ significantly from those of non-pregnant females. The excretion values of mothers bearing a male foetus (17.3 ± 8.9 μg/24 h) are higher than those of mothers with a female foetus (6.4 ± 4.8 μg/24 h). The difference is statistically significant with P = 0.01.


1971 ◽  
Vol 17 (12) ◽  
pp. 1196-1199
Author(s):  
Bernard Klein ◽  
Lois B Lucas

Abstract A new coupled redox procedure has been developed for the determination of glucose in 4 µl of plasma or serum. The photometric endpoint is formation of the violet-blue Fe2+-5-pyridyl benzodiazepin-2-one chelate, for which the absorbance at 580 nm is linear with glucose concentration from 25 to 300 mg/100 ml. Results obtained by the present technique and those obtained by the o-toluidine method and a glucose oxidase method agree well. The mean recovery of glucose added to plasma is 96.6% (range: 92.1-99.6%).


1993 ◽  
Vol 3 (1) ◽  
pp. 41-54 ◽  
Author(s):  
Scott D. Murdoch ◽  
Terry L. Bazzarre ◽  
Ian P. Snider ◽  
Allan H. Goldfarb

This investigation examined the metabolic and performance effects of ingesting solid compared to slurried carbohydrate food (bananas) between two prolonged exhaustive exercise bouts. Eight highly trained bale triathletes performed four exhaustive endurance tests (ET), each separated by at least 2 weeks. Each ET consisted of a 90-min run followed by 90 min of cycling, both at 70%. Workloads were then gradually increased on the cycle, and subjects continued to cycle until exhausted. They then rested for 20 min and ingested one of the following: an artificially sweetened placebo drink (P), slurried bananas (SL), or solid bananas (SO). Bananas were given in equal portions relative to each subject's body weight. Subjects cycled to exhaustion a second time at 70% of their, at which point the mean blood glucose concentration for the combined carbohydrate treatments was significantly higher than that from the P treatment. The mean glucose concentration from the SL treatment did not differ significantly from the SO treatment. These data demonstrate that solid bananas are as effective as slurried bananas in maintaining plasma glucose and in enhancing endurance exercise performance.


1974 ◽  
Vol 47 (6) ◽  
pp. 559-565 ◽  
Author(s):  
P. F. Semple ◽  
W. Carswell ◽  
J. A. Boyle

1. A serial study of renal clearance of urate and inulin was made in thirteen normal women in early, mid and late pregnancy and 6–15 weeks after delivery. 2. The mean serum urate concentration was low in early and mid pregnancy but rose in late pregnancy towards the control value. 3. Clearances of urate and inulin were consistently elevated throughout pregnancy to about 150% of the post-partum values. The ratio of clearance of urate to clearance of inulin was the same in pregnancy as it was after the puerperium. 4. The urinary excretion of urate was increased only in late pregnancy.


1980 ◽  
Vol 85 (1) ◽  
pp. 27-34 ◽  
Author(s):  
M. J. TAYLOR ◽  
G. JENKIN ◽  
J. S. ROBINSON ◽  
G. D. THORBURN ◽  
H. FRIESEN ◽  
...  

SUMMARY The concentration of ovine placental lactogen (oPL) was measured by radioimmunoassay in plasma samples from chronically catheterized ewes and their fetuses from day 110 of gestation to term (about day 145). Concentrations of oPL in the plasma of the mother and fetus were raised after surgery, and remained raised for 3–5 days after the operation. Concentrations of oPL were greatest in the fetus at days 120–124 of gestation, and then declined until delivery. Mean concentrations of oPL in the fetus in late pregnancy for single, twin and triplet pregnancies were 101±6 (s.e.m.), 100±11 and 117±59 ng/ml respectively and were not significantly different. Mean concentrations of oPL in the mother in late pregnancy for single, twin and triplet pregnancies were 718±227, 1387±160 and 1510±459 ng/ml respectively; the difference between these means was significant (P <0·05). Peak concentrations were noted at days 130–139 of gestation after which concentrations fell and were significantly lower on the day of delivery (P <0·01). Concentrations of oPL in the mother showed no circadian rhythm. The mean concentrations of oPL in maternal plasma during late pregnancy was significantly correlated to the combined fetal weight at birth (r = 0·624, P <0·01).


1980 ◽  
Vol 87 (2) ◽  
pp. 293-301 ◽  
Author(s):  
ABIGAIL L. FOWDEN ◽  
R. J. BARNES ◽  
R. S. COMLINE ◽  
MARIAN SILVER

Insulin secretion and the factors influencing β-cell function were investigated in the chronically catheterized fetal foal and mare during the second half of gestation. The response of the fetal β cells to exogenous glucose was also examined. The mean concentration of insulin in the fetal foal was 7·5 ± 0·5 (s.e.m.) μu./ml (n = 20) which was significantly less than the corresponding maternal value of 49·0 ± 5·0μu./ml (n = 20, P<0·01). The insulin concentration in non-pregnant horses was 24·5 ± 1·5 μu./ml (n = 5) which was significantly less than the value in the pregnant animals (P<0·01). However, there was no significant difference in the mean glucose concentration between the groups of adult animals. The insulin concentration was related to the endogenous glucose level in both adult and fetal horses. Wide variation in the maternal insulin concentration was observed above a glucose concentration of about 5·0 mmol/l. The mean concentration of insulin in pregnant mares decreased with increasing gestational age while the mean glucose concentration remained unaltered throughout the second half of gestation. There was no change in the basal concentrations of insulin or glucose in the fetus with gestational age although the fetal β-cell response to exogenous glucose appeared to increase with increasing fetal age after 270 days of gestation (term 330 days). There was a significant arterio-venous difference in the concentration of insulin across the gravid uterus in the mare when the arterial insulin level was greater than 30 μu./ml. Below this value, there was no consistent uptake of insulin by the uterus. The observations are discussed in relation to the regulation of insulin release in utero and the effects of pregnancy on maternal β-cell function.


2009 ◽  
Vol 55 (5) ◽  
pp. 1019-1021 ◽  
Author(s):  
Raymond Gambino ◽  
Janet Piscitelli ◽  
Tomy A Ackattupathil ◽  
Judy L Theriault ◽  
Reynaldo D Andrin ◽  
...  

Abstract Background: Sodium fluoride is the preferred agent to inhibit glycolysis. Its action is not immediate, however, and complete inhibition is delayed for up to 4 hours. A more effective method is needed. Acidification of blood combined with the addition of NaF and EDTA appears to be such a method. We studied whether acidification was indeed more effective than NaF. Methods: We conducted 6 independent studies over a 10-month period at 3 Quest Diagnostics laboratory sites. In each study, we drew venous blood from 6–24 nonfasting employee volunteers into 3 or 4 different serum- or plasma-collection tubes, which were stored under different conditions and aliquoted at different times. We analyzed the aliquots in duplicate by means of a hexokinase-based enzymatic method. Results: The mean glucose concentration decreased by 0.3% at 2 h and by 1.2% at 24 h when blood was drawn into tubes containing citrate buffer, NaF, and EDTA. In contrast, the mean glucose concentration decreased by 4.6% at 2 h and by 7.0% at 24 h when blood was drawn into tubes containing NaF and sodium oxalate. Conclusions: Acidification should replace NaF alone as the recommended method for obtaining an accurate glucose concentration. Diagnostic cut points based on blood samples collected into tubes containing NaF as the only inhibitor of glycolysis are likely to be too low.


1967 ◽  
Vol 37 (4) ◽  
pp. 443-453 ◽  
Author(s):  
IRIS M. TRAYNER ◽  
T. A. WELBORN ◽  
A. H. RUBENSTEIN ◽  
T. RUSSELL FRASER

SUMMARY As measured both by immunoassay and bioassay during a glucose tolerance test (50 g.) on ten subjects in the third trimester of pregnancy, the serum insulin levels fasting, 1 and 2 hr. after glucose were raised at least threefold compared with the levels in 23 non-pregnant women. The renal clearance of immunoassayable insulin was lower than that in the non-pregnant state (the mean in the pregnant subjects was 0·18 ml./min. compared with 0·45 ml./min. in the normal non-pregnant subjects). In the same subjects the mean serum non-suppressible insulin-like activity, which is unaltered by oral glucose, was 1·5 times higher than the non-pregnant mean level, but this difference was not significant. Four pregnant latent diabetics, tested similarly in the latter part of pregnancy, showed even higher fasting serum insulin levels than the normal pregnant subjects, but a lessened response to the same glucose load.


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