Influence of fasting on glycogen depletion in rats during exercise

1983 ◽  
Vol 55 (3) ◽  
pp. 830-833 ◽  
Author(s):  
G. L. Dohm ◽  
E. B. Tapscott ◽  
H. A. Barakat ◽  
G. J. Kasperek
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Plasma Glucose ◽  
Muscle Glycogen ◽  
Glucose Concentration ◽  
Plasma Glucose Concentration ◽  
Control Group ◽  
Glycogen Depletion ◽  
Ad Libitum ◽  
Beta Hydroxybutyrate

We recently observed that a 24-h fasted group of rats could run longer than an ad libitum fed control group before becoming exhausted. Because of the demonstrated importance of glycogen levels and free fatty acid availability during endurance exercise, we have investigated several parameters of carbohydrate and lipid metabolism in exercised and nonexercised rats that were either fed ad libitum or fasted for 24 h. A 24-h fast depleted liver glycogen, lowered plasma glucose concentration, decreased muscle glycogen levels, and increased free fatty acid and beta-hydroxybutyrate concentrations in plasma. During exercise the fasted group had lower plasma glucose concentration, higher plasma concentration of free fatty acids and beta-hydroxybutyrate, and a lower muscle glycogen depletion rate than did the ad libitum fed group. Since fasted rats were able to continue running even when plasma glucose had dropped to levels lower than those of fed-exhausted rats, it seems unlikely that blood glucose level, per se, is a factor in causing exhaustion. These results suggest that fasting increases fatty acid utilization during exercise and the resulting “glycogen sparing” effect may result in increased endurance.

Plasma free fatty acid turnover during insulin-induced hypoglycemia

1961 ◽  
Vol 201 (3) ◽  
pp. 535-539 ◽  
Author(s):  
D. T. Armstrong ◽  
R. Steele ◽  
N. Altszuler ◽  
A. Dunn ◽  
J. S. Bishop ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Glucose Uptake ◽  
Plasma Glucose ◽  
Glucose Concentration ◽  
Insulin Infusion ◽  
Plasma Free Fatty Acid ◽  
Plasma Glucose Concentration ◽  
Free Insulin ◽  
Adrenal Response

Plasma free fatty acid (FFA) concentration falls when an infusion of glucagon-free insulin is initiated in the normal unanesthetized dog in the postabsorptive state. Using C14 palmitate it was shown that the lowered FFA concentration is caused by decreased FFA production. This decreased FFA production accompanies increased glucose uptake by the tissues as demonstrated using C14 glucose. During slow insulin infusion, when plasma glucose concentration remains above 75 mg%, FFA production and concentration remain low. However, during more rapid insulin infusion, when plasma glucose concentration falls below 50 mg%, the initially lowered FFA production rebounds and FFA production and concentration exceed the preinsulin level. Glucose uptake always remains elevated during insulin infusion. Dibenzyline or guanethidine pretreatment blocks the rebound in FFA production. Thus decreased FFA production, due presumably to decreased FFA release by adipose tissue because of insulin-stimulated glucose uptake, can be overpowered by a sympatho-adrenal response to hypoglycemia during a continued infusion of insulin and a resulting continued increased glucose uptake.

Failure to Observe Changes in Selected Metabolites Following Removal of the Stannius Corpuscles from the Freshwater North American Eel, Anguilla rostrata

1972 ◽  
Vol 29 (9) ◽  
pp. 1362-1364 ◽  
Author(s):  
David Gordon Butler
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Plasma Glucose ◽  
North American ◽  
Muscle Glycogen ◽  
Liver Glycogen ◽  
Anguilla Rostrata ◽  
American Eel ◽  
Stannius Corpuscles

There were no measurable changes in plasma glucose, protein, or free fatty acid concentrations in the freshwater North American eel, Anguilla rostrata, 2 weeks after excision of the Stannius corpuscles. Liver glycogen concentrations were normal but muscle glycogen increased. Plasma Na decreased and K and Ca increased. These data indicate that secretions of the Stannius corpuscles are primarily concerned with ionoregulation.

scholarly journals Breed and diurnal effects on leptin and glucose concentrations in tropical cattle

2021 ◽  
Vol 44 (3) ◽  
pp. 104-109
Author(s):  
N. Okwelum ◽  
B. O. Oduguwa ◽  
N. Yahya ◽  
O. Gazal ◽  
O. A. Osinowo
Keyword(s):  
Plasma Glucose ◽  
Glucose Concentration ◽  
Cattle Breed ◽  
Time Of Day ◽  
Plasma Glucose Concentration ◽  
Breed Differences ◽  
Ad Libitum ◽  
White Fulani ◽  
Plasma Leptin

The effects of breed and time of day was evaluated on plasma leptin and glucose concentrations in four breeds of cattle. The breeds were Muturu, White Fulani, Ndama and Muturu x White Fulani cross. Animals had ad-libitum access to feed and water. Each animal was weighed daily and bled by jugular venipuncture using Vacutainer kits for three consecutive days. Plasma leptin was determined using the Millipore Multi-species radioimmunoassay and plasma glucose was determined using the Wako Autokit Glucose technique. Plasma leptin was significantly (P<0.0001) dependent on breed. The Muturu breed had the lowest amount of leptin (3.9 ± 1.8 ng/ml) while the White Fulani breed had the highest level (8.5 ± 3.2 ng/ml). There was a significant correlation between bodyweight and leptin. Leptin level was not affected by time of day. Mean plasma glucose ranged from 42.7 to 54.7 mg/dL and was significantly (P = 0.019) dependent on cattle breed. Also, time of day had no effect on plasma glucose concentration. These data indicated that significant breed differences exist in leptin concentrations in tropical cattle. These differences may reflect the disparity in muscularity and adiposity in the breeds.

scholarly journals Electroacupuncture at Bilateral ST36 Acupoints: Inducing the Hypoglycemic Effect through Enhancing Insulin Signal Proteins in a Streptozotocin-Induced Rat Model during Isoflurane Anesthesia

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Kee-Ming Man ◽  
Yu-Chen Lee ◽  
Ying-I. Chen ◽  
Yung Hsiang Chen ◽  
Shih Liang Chang ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Rat Model ◽  
Plasma Glucose ◽  
Wistar Rats ◽  
Positive Change ◽  
Control Group ◽  
Isoflurane Anesthesia ◽  
Negative Change

In rats with 2-deoxy-2-(3-(methyl-3-nitrosoureido)-d-glucopyranose streptozotocin- (STZ-) induced insulin-dependent diabetes (IDDM), continuous 15 Hz electrical stimulation at bilateral ST36 acupoints for 30 and 60 minutes has been shown to prevent hyperglycemia. We hypothesized that the mechanism of action in STZ-induced IDDM rats is that electrical stimulation at bilateral ST36 acupoints is effective in improving insulin receptor substrate type 1 (IRS-1) and glucose transporter type 4 (GLUT4) protein expressions associated with counteracting both plasma glucose and free fatty acid (FFA) levels during isoflurane anesthesia. In this study, twenty-six healthy male Wistar rats, weighing 250–350 g and aged 8–10 weeks were tested. Rats in the experimental electroacupuncture (EA) group (n = 13) received 15 Hz electrical stimulation at bilateral ST 36 acupoints for 30 and 60 minutes. Rats in the control group (n = 13) were handled but not subjected to the stimulation treatment. In both IDDM and normal Wistar rats, we observed a negative change in plasma glucose levels when rats were given the EA treatment, but a positive change in plasma glucose without EA treatment relative to baseline. Within the IDDM group, a negative change in FFA levels was observed when rats were given the EA treatment, while a positive change in the FFA level was shown without the EA treatment. In the expressed protein signals, we found a significant elevation in both GLUT4 and IRS-1 proteins in the IDDM group treated by EA. Moreover, we found a significant mean difference between GLUT4 and IRS-1 protein expression levels relative to β-actin. Our findings suggested that EA at bilateral ST36 acupoints could serve as an effective strategy for lowering plasma glucose by decreasing free fatty acid levels and improving the expression of IRS-1 and GLUT4 proteins in a STZ-IDDM rat model during isoflurane anesthesia.

Measurement of plasma glucose, free fatty acid, lactate, and insulin for 24 h in patients with NIDDM

Diabetes ◽  
1988 ◽  
Vol 37 (8) ◽  
pp. 1020-1024 ◽  
Author(s):  
G. M. Reaven ◽  
C. Hollenbeck ◽  
C. Y. Jeng ◽  
M. S. Wu ◽  
Y. D. Chen
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Plasma Glucose
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