scholarly journals Early Changes in Plasma Insulin and Growth Hormone Levels after Feeding in Lambs and Adult Sheep

1974 ◽  
Vol 27 (2) ◽  
pp. 157 ◽  
Author(s):  
JM Bassett
Keyword(s):  
Growth Hormone ◽  
Plasma Glucose ◽  
Plasma Insulin ◽  
Amino Nitrogen ◽  
Insulin Concentration ◽  
Plasma Growth Hormone ◽  
Plasma Insulin Concentration ◽  
Adult Sheep ◽  
Nitrogen Concentrations ◽  
Comparable Magnitude

When lambs 1-3 months of age ingested 250 or 500 m1 of milk by sucking vigorously from a teat, there was a rapid increase in their plasma insulin concentration to a maximum 5 min after starting to suck. At the same time plasma growth hormone (GH) levels declined rapidly. Changes of comparable magnitude were also seen when lambs drank milk diluted with water or vigorously ate chopped lucerne hay, when adult wether sheep ate dry feed rapidly, and when an adult wether fitted with an oesophageal fistula was 'sham-fed'. The changes were not seen when sheep, although offered food, did not eat. These responses were not closely related to changes in plasma glucose or ",-amino nitrogen concentrations and they evidently involve reflex nervous mechanisms.

THE RESPONSE OF PLASMA INSULIN, GLUCOSE AND NON-ESTERIFIED FATTY ACIDS TO VARIOUS HORMONES, NUTRIENTS AND DRUGS IN THE DOMESTIC FOWL

1970 ◽  
Vol 46 (2) ◽  
pp. 243-260 ◽  
Author(s):  
D. R. LANGSLOW ◽  
E. J. BUTLER ◽  
C. N. HALES ◽  
A. W. PEARSON
Keyword(s):  
Plasma Glucose ◽  
Glucose Concentration ◽  
Domestic Fowl ◽  
Plasma Insulin ◽  
Amino Nitrogen ◽  
Insulin Concentration ◽  
Nefa Concentration ◽  
Plasma Nefa ◽  
Plasma Insulin Concentration ◽  
Nitrogen Concentrations

SUMMARY The relationships between plasma insulin, glucose, non-esterified fatty acid (NEFA) and α-amino nitrogen concentrations in the domestic fowl have been studied. During a 72-hr. fast the plasma glucose concentration fell while the NEFA concentration rose but there was no change in plasma insulin concentration. Both oral and intracardiac glucose increased the plasma insulin concentration and lowered the plasma NEFA and α-amino nitrogen concentrations. Oral amino acids increased plasma insulin and glucose concentrations but had no effect on plasma NEFA. Intracardiac ox insulin depressed plasma glucose and α-amino nitrogen and increased the plasma NEFA concentration. Intracardiac glucagon increased both plasma glucose and NEFA and depressed the plasma α-amino nitrogen concentrations but had no significant effect on plasma insulin. Intracardiac adrenaline had no effect on plasma NEFA but increased plasma glucose concentration and caused a small depression in plasma insulin concentration.

scholarly journals Glucose–insulin relationships and thyroid status of cockerels selected for high or low residual food consumption

2000 ◽  
Vol 83 (6) ◽  
pp. 645-651 ◽  
Author(s):  
Jean-François Gabarrou ◽  
Pierre Andre Geraert ◽  
John Williams ◽  
Laurent Ruffier ◽  
Nicole Rideau
Keyword(s):  
Food Consumption ◽  
Plasma Glucose ◽  
Plasma Insulin ◽  
Plasma Concentrations ◽  
Insulin Concentration ◽  
Glucose Disposal ◽  
Oral Glucose ◽  
Thyroid Status ◽  
Plasma Insulin Concentration ◽  
Diet Induced Thermogenesis

The plasma glucose–insulin relationships and thyroid status were investigated in two lines of adult cockerels divergently selected for high (R+) or low (R-) residual food consumption (RFC). For a given body weight, R+ birds had a 74 % higher food intake than R- birds. Plasma glucose concentrations were significantly lower in the R+ line compared with the R- when fasted, whereas R+ birds exhibited a significantly lower plasma insulin concentration than R- birds either in fed or fasted state. After an overnight fast, R+ birds also exhibited a higher sensitivity to exogenous insulin in view of its more pronounced hypoglycaemic effect. After an oral glucose load, the glucose disposal of R+ cockerels was faster despite lower glucose-induced plasma insulin concentration. Whilst plasma triacylglycerol concentrations were lower in the R+ line when fed, plasma non-esterified fatty acid concentrations were higher in fasted R+ than R- cockerels (684v.522 μmol/l). Higher plasma triiodothyronine concentrations were observed in fed R+ compared with R- birds (3·0v.2·1 nmol/l respectively). The higher plasma concentrations of triiodothyronine associated with lower concentrations of insulin could account for the leanness and the elevated diet-induced thermogenesis previously observed in the R+ line.

Effects of hyperprolactinaemia on glucose tolerance and insulin release in male and female rats

1997 ◽  
Vol 153 (3) ◽  
pp. 423-428 ◽  
Author(s):  
F M Reis ◽  
A M Reis ◽  
C C Coimbra
Keyword(s):  
Glucose Tolerance ◽  
Insulin Release ◽  
Plasma Glucose ◽  
Plasma Insulin ◽  
Female Rats ◽  
Insulin Concentration ◽  
Glucose Load ◽  
Plasma Insulin Concentration ◽  
Male And Female ◽  
Male And Female Rats

Abstract It has been shown that prolactin (PRL) induces glucose intolerance, hyperinsulinaemia and insulin resistance in several animal species, including rats. However, the sex differences regarding glucose homeostasis and insulin release in hyperprolactinaemic subjects have not been assessed to date. In the present study, hyperprolactinaemic (pituitary-grafted) or control (sham-operated) male and female rats were submitted to an i.v. glucose tolerance test (30 mg/100 g body weight, 30% glucose). Grafted female rats had fasting plasma glucose concentrations 26% above control (P<0·01). After the glucose load there was a rapid and pronounced increase in plasma glucose levels in all animal groups, followed by a return to basal values within 30 min. However, the glucose concentrations in hyperprolactinaemic rats were significantly greater than those in controls at 5 min (males, P<0·05) and 30 min (females, P<0·05). The glucose disappearance rate was significantly increased in the grafted females compared with control (P<0·01) and slightly increased in the grafted males. Plasma insulin concentration increased just after glucose load and returned to basal values within 5 min in all groups except for the grafted females, which had recovered their basal insulin levels at 15 min. The grafted male rats had insulin concentrations higher than those of sham-operated controls at 2 min (28·9 ± 3·6 vs 17·3 ± 2·1 μU/ml, P<0·01), whereas females had plasma insulin concentrations greater than those in sham-operated controls 10 min after the glucose load (15·9 ± 1·9 vs 10·1 ± 1·4 μU/ml, P<0·05). The areas under the plasma insulin concentration–time curves were also significantly increased in the hyperprolactinaemic rats and were positively correlated with plasma PRL concentrations (r=0·613, P<0·01). These results demonstrate that moderate chronic hyperprolactinaemia is associated with increased glucose-induced insulin release, which was altered at different times after the glucose load in grafted male and female rats, whereas fasting hyperglycaemia was observed only in grafted females, indicating a sexual dimorphism in the diabetogenic effects of PRL in rats. Journal of Endocrinology (1997) 153, 423–428

Sensitivity of insulin secretion to feedback inhibition by hyperinsulinaemia

1981 ◽  
Vol 98 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Ralph A. DeFronzo ◽  
Christian Binder ◽  
John Wahren ◽  
Philip Felig ◽  
Eleuterio Ferrannini ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Plasma Glucose ◽  
Plasma Insulin ◽  
Feedback Inhibition ◽  
Normal Subjects ◽  
Insulin Concentration ◽  
Plasma Insulin Concentration ◽  
C Peptide ◽  
Endogenous Insulin ◽  
Arterial Plasma

Abstract. The ability of insulin to inhibit its own secretion was examined in 15 normal subjects given an intravenous infusion of insulin in a dose of 0.25, 0.50, 1.0, 5.0 or 10.0 mU/kg/min for two hours. Arterial plasma insulin concentration achieved during the infusion segregated into three levels of hyperinsulinaemia: 35 ± 1 (mean ± sem), 87 ± 15 and 828 ± 210 μU/ml. Plasma glucose concentration was kept constant at the basal level by a variable glucose infusion. Fasting C-peptide (0.29 ± 0.02 pmol/ml) fell significantly in all subjects during hyperinsulinaemia and reached a concentration of 0.19 ± 0.03 pmol/ml at 60 min and 0.14 ± 0.03 at 120 min after the start of the insulin infusion. The C-peptide response was not related to the infusion dose nor to the steady state plasma insulin concentration. It is concluded that (a) basal insulin secretion as evaluated from C-peptide measurements is inhibited by small (24 ± 3 μU/ml) physiological elevations in plasma insulin concentration independent of changes in plasma glucose, and (b) supraphysiological or even pharmacological elevations in plasma insulin do not result in a further decrease in endogenous insulin secretion above that achieved with mild hyperinsulinaemia.

THE EFFECT OF A HIGH-FAT DIET ON GLUCOSE, INSULIN SENSITIVITY AND PLASMA INSULIN IN RATS

1968 ◽  
Vol 42 (4) ◽  
pp. 489-494 ◽  
Author(s):  
E. BLÁZQUEZ ◽  
C. LOPEZ QUIJADA
Keyword(s):  
Plasma Glucose ◽  
High Fat Diet ◽  
Plasma Insulin ◽  
Diet Group ◽  
Insulin Concentration ◽  
Control Group ◽  
High Fat ◽  
Plasma Insulin Concentration ◽  
The Mean

SUMMARY The influence of the diet on the levels of insulin was studied in rats on a high-fat diet. Plasma and glucose insulin concentrations of a control group and of rats on a high-fat diet were compared, and so was the insulin concentration in the pancreas of the two groups. The mean plasma insulin concentration in the control group was 40 μ-u./ml. and that of insulin extracted from the pancreas was 2·5 μg./100 mg. tissue; plasma glucose was 156 mg./100 ml. The animals fed on a high-fat diet showed diabetic features. The mean plasma insulin level was 9 μ-u./ml., and plasma glucose increased to 210 mg./100 ml. The insulin concentration in the pancreas was not significantly different from that in the controls. In vitro the epididymal fat and the diaphragm of the high-fat-diet group were less sensitive to insulin than the same tissues in the control group.

CHANGES IN PLASMA GROWTH HORMONE AND INSULIN OF THE HUMAN FOETUS FOLLOWING HYSTEROTOMY

1971 ◽  
Vol 66 (4) ◽  
pp. 577-586 ◽  
Author(s):  
R. C. Turner ◽  
B. Schneeloch ◽  
P. Paterson
Keyword(s):  
Growth Hormone ◽  
Plasma Insulin ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Immunoreactive Insulin ◽  
Plasma Growth Hormone ◽  
Plasma Insulin Concentration ◽  
Plasma Immunoreactive Insulin ◽  
The Mean ◽  
Serial Samples

ABSTRACT Plasma immunoreactive insulin and growth hormone of 20–24 weeks' gestation human foetuses were assayed in serial samples following delivery by hysterotomy. The mean umbilical cord plasma growth hormone concentration was 71 ng/ml (range 13–120 ng/ml) and the mean plasma insulin was 5 μU/ml (range 2–8 μU/ml). Following delivery the growth hormone levels increased, but there was no significant change in plasma insulin concentration. The hypothalamic-hypophyseal axis controlling growth hormone secretion appears to be developed by 20 weeks' gestation, and »stress« appears to be a provocative stimulus.

Glucose intolerance following chronic metabolic acidosis in man.

1979 ◽  
Vol 236 (4) ◽  
pp. E328 ◽  
Author(s):  
R A DeFronzo ◽  
A D Beckles
Keyword(s):  
Metabolic Acidosis ◽  
Glucose Metabolism ◽  
Plasma Glucose ◽  
Glucose Concentration ◽  
Plasma Insulin ◽  
Glucose Infusion ◽  
Insulin Concentration ◽  
Plasma Insulin Concentration ◽  
Chronic Metabolic Acidosis ◽  
Tissue Sensitivity

The effect of chronic metabolic acidosis (0.1 g/(kg . day) X 3 days) on carbohydrate metabolism was examined with the glucose-clamp technique in 16 healthy volunteers. Hyperglycemic clamp. Plasma glucose concentration is acutely raised and maintained 125 mg/dl above the basal level. Because the glucose concentration is held constant, the glucose infusion rate is an index of glucose metabolism (M). Following NH4Cl, M decreased from 8.95 +/- 1.12 to 7.35 +/- 0.76 (P less than 0.05) despite an increased plasma insulin concentration (I) 23 +/- 9%, P less than 0.05). Consequently the M/I ratio, an index of tissue sensitivity to insulin, decreased by 32 +/- 5% (P less than 0.005). Euglycemic clamp. Plasma insulin concentration is acutely raised and maintained 101 +/- 3 microU/ml above basal and plasma glucose is held constant at the fasting level by a variable glucose infusion (M). Following NH4Cl both M and M/I decreased by 15 +/- 4% (P = 0.005) and 15 +/- 5% (P = 0.01), respectively. Metabolic acidosis had no effect on basal [3-3H]glucose production or the percent of decline (91 +/- 4%) following hyperinsulinemia. Both hyperglycemic and euglycemic clamp studies indicate that impaired glucose metabolism following metabolic acidosis results from impaired tissue sensitivity to insulin.

scholarly journals Postprandial glucose and insulin profiles following a glucose-loaded meal in cats and dogs

2011 ◽  
Vol 106 (S1) ◽  
pp. S101-S104 ◽  
Author(s):  
Adrian K. Hewson-Hughes ◽  
Matthew S. Gilham ◽  
Sarah Upton ◽  
Alison Colyer ◽  
Richard Butterwick ◽  
...  
Keyword(s):  
Body Weight ◽  
Plasma Glucose ◽  
Test Meal ◽  
Glucose Concentration ◽  
Plasma Insulin ◽  
Plasma Glucose Concentration ◽  
Insulin Concentration ◽  
Metabolic Adaptation ◽  
Plasma Insulin Concentration ◽  
High Blood Glucose

Data from intravenous (i.v.) glucose tolerance tests suggest that glucose clearance from the blood is slower in cats than in dogs. Since different physiological pathways are activated following oral administration compared with i.v. administration, we investigated the profiles of plasma glucose and insulin in cats and dogs following ingestion of a test meal with or without glucose. Adult male and female cats and dogs were fed either a high-protein (HP) test meal (15 g/kg body weight; ten cats and eleven dogs) or a HP+glucose test meal (13 g/kg body-weight HP diet+2 g/kg body-weight d-glucose; seven cats and thirteen dogs) following a 24 h fast. Marked differences in plasma glucose and insulin profiles were observed in cats and dogs following ingestion of the glucose-loaded meal. In cats, mean plasma glucose concentration reached a peak at 120 min (10·2, 95 % CI 9·7, 10·8 mmol/l) and returned to baseline by 240 min, but no statistically significant change in plasma insulin concentration was observed. In dogs, mean plasma glucose concentration reached a peak at 60 min (6·3, 95 % CI 5·9, 6·7 mmol/l) and returned to baseline by 90 min, while plasma insulin concentration was significantly higher than pre-meal values from 30 to 120 min following the glucose-loaded meal. These results indicate that cats are not as efficient as dogs at rapidly decreasing high blood glucose levels and are consistent with a known metabolic adaptation of cats, namely a lack of glucokinase, which is important for both insulin secretion and glucose uptake from the blood.

Effect of insulin on uptake of metabolic substrates by the sheep fetus

1986 ◽  
Vol 251 (3) ◽  
pp. E349-E356 ◽  
Author(s):  
J. R. Milley ◽  
J. S. Papacostas ◽  
B. K. Tabata
Keyword(s):  
Plasma Insulin ◽  
Amino Nitrogen ◽  
Blood Gases ◽  
Plasma Insulin Concentration ◽  
Blood Concentrations ◽  
Fetal Plasma ◽  
Metabolic Substrates ◽  
Umbilical Blood ◽  
Nitrogen Concentrations ◽  
Near Term

To measure the effect of fetal hyperinsulinemia on fetal oxidative metabolic rate and the uptake of fetal oxidative substrates, we operated on 12 near-term ewes under spinal anesthesia and placed catheters in the fetus under local anesthesia. Four days after surgery, we began an 18-h insulin infusion, at the end of which we drew blood samples for analysis of oxygen, glucose, lactate, amino-nitrogen concentrations, blood gases, pH, hematocrit, and plasma insulin concentrations, then injected radiolabeled microspheres to measure umbilical blood flow. Three to five infusions were given to each fetus. Fetal plasma insulin concentrations varied from 0.3 to 60 microU/ml. As fetal plasma insulin concentration rose, the blood concentrations of oxygen, glucose, lactate, and amino-nitrogen fell, but the fetal uptakes of oxygen, glucose, and amino-nitrogen rose. The rise of fetal oxygen uptake occurred by increasing oxygen extraction, resulting in arterial hypoxemia. The increase of the glucose uptake was sufficient to account for an increased fraction of oxidative metabolism, allowing the increased uptake of amino acids to be used for either synthetic or oxidative purposes.

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