scholarly journals Effect of Glucose Load on Synthesis of Plasma Glucose in Lactating Cows

1975 ◽  
Vol 58 (3) ◽  
pp. 362-370 ◽  
Author(s):  
J.R. Thompson ◽  
G. Weiser ◽  
Katsuo Seto ◽  
A.L. Black
Keyword(s):  
Plasma Glucose ◽  
Glucose Load ◽  
Lactating Cows ◽  
Effect Of Glucose

scholarly journals Acute plasma glucose increase, but not early insulin response, regulates plasma ghrelin

2003 ◽  
pp. 403-406 ◽  
Author(s):  
L Briatore ◽  
G Andraghetti ◽  
R Cordera
Keyword(s):  
Plasma Glucose ◽  
Healthy Subjects ◽  
Insulin Response ◽  
Glucose Levels ◽  
Healthy Control ◽  
Early Insulin Response ◽  
Effect Of Glucose ◽  
Type 2 Diabetic

OBJECTIVE: The independent role of glucose and insulin in ghrelin regulation is still controversial; this is also because in healthy subjects it is difficult to isolate the increase of glucose from that of insulin. The aim of this study was to discriminate the effect of glucose increase alone and early insulin response on plasma ghrelin, comparing ghrelin variation after i.v. glucose between healthy subjects and type 2 diabetic (T2DM) subjects, in whom the early insulin response to i.v. glucose is abolished. METHODS: Plasma glucose, insulin and ghrelin levels were measured 0, 3, 5, 10, 30, 45 and 60 min after a 5 g glucose i.v. bolus in seven healthy control subjects and eight T2DM subjects. RESULTS: There were no significant differences in body mass index, basal insulin and basal ghrelin between T2DM and healthy subjects. Basal glucose levels were higher in T2DM subjects than in controls. After i.v. glucose administration, plasma glucose increased significantly in both groups and the glucose peak was higher in T2DM subjects than in controls (9.67+/-1.25 (s.d.) vs 6.88+/-1.00 mmol/l, P<0.01). Insulin increased rapidly in controls, while in T2DM subjects, plasma insulin did not rise in the first 10 min. After the glucose bolus, plasma ghrelin showed a significant reduction both in controls and in T2DM subjects after 5 min. CONCLUSION: These findings indicate that a low-dose i.v. glucose bolus reduces ghrelin both in controls and in T2DM subjects and therefore that early insulin response does not affect plasma ghrelin.

Plasma glucose concentration determines direct versus indirect liver glycogen synthesis

1986 ◽  
Vol 251 (5) ◽  
pp. E584-E590 ◽  
Author(s):  
C. H. Lang ◽  
G. J. Bagby ◽  
H. L. Blakesley ◽  
J. L. Johnson ◽  
J. J. Spitzer
Keyword(s):  
Plasma Glucose ◽  
Glucose Concentration ◽  
Infusion Rate ◽  
Glycogen Synthesis ◽  
Liver Glycogen ◽  
Glucose Infusion ◽  
Glucose Infusion Rate ◽  
Hepatic Glycogen ◽  
Glucose Load ◽  
Indirect Pathway

In the present study hepatic glycogenesis by the direct versus indirect pathway was determined as a function of the glucose infusion rate. Glycogen synthesis was examined in catheterized conscious rats that had been fasted 48 h before receiving a 3-h infusion (iv) of glucose. Glucose, containing tracer quantities of [U-14C]- and [6-3H]glucose, was infused at rates ranging from 0 to 230 mumol X min-1 X kg-1. Plasma concentrations of glucose, lactate, and insulin were positively correlated with the glucose infusion rate. Despite large changes in plasma glucose, lactate, and insulin concentrations, the rate of hepatic glycogen deposition (0.46 +/- 0.03 mumol X min-1 X g-1) did not vary significantly between glucose infusion rates of 20 and 230 mumol X min-1 X kg-1. However, the percent contribution of the direct pathway to glycogen repletion gradually increased from 13 +/- 2 to 74 +/- 4% in the lowest to the highest glucose infusion rates, with prevailing plasma glucose concentrations from 9.4 +/- 0.5 to 21.5 +/- 2.1 mM. Endogenous glucose production was depressed (by up to 40%), but not abolished by the glucose infusions. Only a small fraction (7-14%) of the infused glucose load was incorporated into liver glycogen via the direct pathway irrespective of the glucose infusion rate. Our data indicate that the relative contribution of the direct and indirect pathways of hepatic glycogen synthesis are dependent on the glucose load or plasma glucose concentration and emphasize the predominance of the indirect pathway of glycogenesis at plasma glucose concentrations normally observed after feeding.

Glucose metabolism in the lactating beagle dog

1962 ◽  
Vol 202 (2) ◽  
pp. 329-333 ◽  
Author(s):  
Jack R. Luick ◽  
Arthur L. Black ◽  
Harold R. Parker ◽  
Mogens G. Simesen
Keyword(s):  
Plasma Glucose ◽  
Metabolic Pathways ◽  
Milk Fat ◽  
Specific Activity ◽  
Energy Requirement ◽  
Similar Data ◽  
Lactating Cows ◽  
Diabetic Dog ◽  
Oxidation Of Glucose

A study was made of the role of glucose as an oxidizable substrate and as a source of C for the synthesis of milk using lactating beagle dogs. Uniformly C14-labeled glucose was used as a tracer of these metabolic pathways. Our data indicate that the labeled glucose was completely eliminated from the dog's body within 24 hr after injection. Sixty percent of the injected dose appeared in the expired CO2, 40% in the various milk products. Comparison of the integrated specific activity of plasma glucose with that of expired CO2 indicates that 36% of the dog's energy requirement is met by the oxidation of glucose. This presumably means that the catabolism of noncarbohydrate substances must be of considerable importance to the energy metabolism of not only the fasted dog and the diabetic dog, as has been demonstrated earlier, but also of the fed dog. We have also shown that 68–100% of the C required for the synthesis of lactose is derived from plasma glucose. In addition, plasma glucose contributes 7.2–12% of milk protein C and 5.1–8.7% of milk fat C. These results are compared with similar data obtained earlier in our laboratory using lactating cows and sows.

scholarly journals Carob pulp preparation rich in insoluble dietary fibre and polyphenols increases plasma glucose and serum insulin responses in combination with a glucose load in humans

2007 ◽  
Vol 98 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Sindy Gruendel ◽  
Baerbel Otto ◽  
Ada L. Garcia ◽  
Karen Wagner ◽  
Corinna Mueller ◽  
...  
Keyword(s):  
Plasma Glucose ◽  
Dietary Fibre ◽  
Glucose Solution ◽  
Serum Insulin ◽  
Acylated Ghrelin ◽  
Glucose Load ◽  
Insulin Metabolism ◽  
Dietary Polyphenols ◽  
Insoluble Dietary Fibre ◽  
Insulin Responses

Dietary fibre consumption is associated with improved glucose homeostasis. In contrast, dietary polyphenols have been suggested to exert both beneficial and detrimental effects on glucose and insulin metabolism. Recently, we reported that a polyphenol-rich insoluble dietary fibre preparation from carob pulp (carob fibre) resulted in lower postprandial acylated ghrelin levels after a liquid meal challenge test compared with a control meal without supplementation. The effects may, however, differ when a different food matrix is used. Thus, we investigated the effects of carob fibre on glucose, insulin and ghrelin responses in healthy humans in combination with a glucose load. In a randomized single-blind cross-over study involving twenty healthy subjects (aged 22–62 years), plasma glucose, total and acylated ghrelin, and serum insulin were repeatedly assessed before and after the ingestion of 200 ml water with 50 g glucose and 0, 5, 10 or 20 g carob fibre over a period of 180 min. The intake of 5 and 10 g carob fibre increased the plasma glucose by 47 % and 64 % (P < 0·001), and serum insulin by 19·9 and 24·8 % (P < 0·001), compared with the control. Plasma acylated ghrelin concentrations did not change significantly after the consumption of carob-enriched glucose solution. Total ghrelin decreased only after 10 g carob fibre (P < 0·001) compared with control. In conclusion, we showed that polyphenol-rich carob fibre, administered within a water–glucose solution, increases postprandial glucose and insulin responses, suggesting a deterioration in glycaemic control.

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

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