Glycemic and Insulinemic Response to Preexercise Carbohydrate Feedings

1994 ◽  
Vol 4 (1) ◽  
pp. 46-53 ◽  
Author(s):  
John G. Seifert ◽  
Greg L. Paul ◽  
Dennis E. Eddy ◽  
Robert Murray
Keyword(s):  
Plasma Glucose ◽  
Plasma Insulin ◽  
Glucose Solution ◽  
Physiological Responses ◽  
Metabolic Responses ◽  
Moderate Intensity ◽  
Baseline Values ◽  
Glucose Plasma ◽  
Insulinemic Response

The effects of preexercise hyperinsulinemia on exercising plasma glucose, plasma insulin, and metabolic responses were assessed during 50 min cycling at 62%. Subjects were fed a 6% sucrose/glucose solution (LCHO) or a 20% maltodextrin/glucose solution (HCHO) to induce changes in plasma insulin. During exercise, subjects assessed perceived nauseousness and lightheadedness. By the start of exercise, plasma glucose and plasma insulin had increased. In the LCHO trial, plasma glucose values significantly decreased below the baseline value at 30 min of exercise. However, by 40 min, exercise plasma glucose and insulin values were similar to the baseline value. Exercise plasma glucose and insulin did not differ from baseline values in the HCHO trial. Ingestion of LCHO or HCHO was not associated with nausea or lightheadedness. It was concluded that the hyperinsulinemia induced by preexercise feediigs of CHO did not result in frank hypoglycemia or adversely affect sensory or physiological responses during 50 min of moderate-intensity cycling.

Penetration of peripheral glucose and insulin into cerebrospinal fluid in rats

1988 ◽  
Vol 255 (2) ◽  
pp. R200-R204 ◽  
Author(s):  
A. B. Steffens ◽  
A. J. Scheurink ◽  
D. Porte ◽  
S. C. Woods
Keyword(s):  
Cerebrospinal Fluid ◽  
Plasma Glucose ◽  
Plasma Insulin ◽  
Glucose Solution ◽  
Base Line ◽  
Jugular Veins ◽  
Left And Right ◽  
Freely Moving ◽  
Ad Libitum ◽  
Glucose Plasma

In this study the penetration of plasma insulin and glucose into the cerebrospinal fluid (CSF) was investigated. Rats were implanted with cannulas in the cisterna magna and into the left and right jugular veins. Freely moving rats were intravenously infused during 4 h with either glucose solution (10 mg/min) or saline. Before, during, and after the infusions, simultaneous blood and CSF samples were taken. Infusion of glucose led to an immediate rise of both plasma glucose and insulin. Although CSF glucose followed plasma glucose within 10 min, CSF insulin was unchanged until 40 min. After termination of the glucose infusion, levels of all substances returned to base line within 10 min. Twenty-four-hour food deprivation resulted in a significant decrease of plasma glucose, plasma insulin, CSF glucose, and CSF insulin. At the onset of eating after deprivation, an increase of plasma glucose and insulin occurred within 10 min, whereas CSF glucose was delayed between 10 and 40 min, after which ad libitum values were attained or surpassed. CSF insulin always remained below ad libitum levels. It is concluded that 1) glucose and insulin penetrate into the CSF and 2) CSF insulin and glucose can fulfill a putative feedback in homeostatic control of food intake and body weight.

Mechanism, temporal patterns, and magnitudes of the metabolic responses to the KATP channel agonist diazoxide

2005 ◽  
Vol 288 (1) ◽  
pp. E80-E85 ◽  
Author(s):  
Bharathi Raju ◽  
Philip E. Cryer
Keyword(s):  
Fatty Acids ◽  
Insulin Secretion ◽  
Fatty Acid ◽  
Plasma Glucose ◽  
Plasma Insulin ◽  
Temporal Patterns ◽  
Metabolic Responses ◽  
Nonesterified Fatty Acid ◽  
Nonesterified Fatty Acids ◽  
C Peptide

To assess the mechanism, temporal patterns, and magnitudes of the metabolic responses to the ATP-dependent potassium channel agonist diazoxide, neuroendocrine and metabolic responses to intravenous diazoxide (saline, 1.0 and 2.0 mg/kg) and oral diazoxide (placebo, 4.0 and 6.0 mg/kg) were assessed in healthy young adults. Intravenous diazoxide produced rapid, but transient, decrements ( P = 0.0023) in plasma insulin (e.g., nadirs of 2.8 ± 0.5 and 1.8 ± 0.3 μU/ml compared with 7.0 ± 1.0 μU/ml after saline at 4.0–7.5 min) and C-peptide ( P = 0.0228) associated with dose-related increments in plasma glucose ( P = 0.0044) and serum nonesterified fatty acids ( P < 0.0001). After oral diazoxide, plasma insulin appeared to decline, as did C-peptide, again associated with dose-related increments in plasma glucose ( P < 0.0001) and serum nonesterified fatty acids ( P = 0.0141). Plasma glucagon, as well as cortisol and growth hormone, was not altered. Plasma epinephrine increased ( P = 0.0215) slightly only after intravenous diazoxide. There were dose-related increments in plasma norepinephrine ( P = 0.0038 and P = 0.0005, respectively), undoubtedly reflecting a compensatory sympathetic neural response to vasodilation produced by diazoxide, but these would not raise plasma glucose or serum nonesterified fatty acid levels. Thus selective suppression of insulin secretion, without stimulation of glucagon secretion, raised plasma glucose and serum nonesterified fatty acid concentrations. These findings define the temporal patterns and magnitudes of the metabolic responses to diazoxide and underscore the primacy of regulated insulin secretion in the physiological regulation of postabsorptive carbohydrate and lipid metabolism.

scholarly journals Comparison of the Effects of Acarbose and TZQ-F, a New Kind of Traditional Chinese Medicine to Treat Diabetes, Chinese Healthy Volunteers

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Huang Yuhong ◽  
Fu Wenxu ◽  
Li Yanfen ◽  
Liu Yu ◽  
Li Ziqiang ◽  
...  
Keyword(s):  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Adverse Events ◽  
Plasma Glucose ◽  
Plasma Insulin ◽  
Double Blind ◽  
C Peptide ◽  
Treatment Of Diabetes ◽  
Glucose Plasma ◽  
Gastrointestinal Adverse Events

Ethnopharmacological Relevance. TZQ-F has been traditionally used in Traditional Chinese Medicine as a formula for the treatment of diabetes.Aim of the Study. This study aims to compare the pharmacologic effects and gastrointestinal adverse events between TZQ-F and acarbose.Methods. The double-blind randomized placebo-controlled fivefold crossover study was performed in 20 healthy male volunteers. Plasma glucose, plasma IRI, and plasma C-peptide were measured to assess the pharmacologic effects. Flatus and bowel activity were measured to assess the adverse event of gastrointestinal effect.Results. 3 and 4 tablets of TZQ decreased theCmaxof plasma glucose compared with that of the previous day and with placebo. 3 tablets also decreasedCmaxof plasma C-peptide compared with placebo. 4 tablets increasedCmaxof plasma insulin after breakfast and the AUC of plasma C-peptide after breakfast and dinner. 2 tablets did not decrease plasma glucose and elevated theCmaxand AUC of C-peptide after breakfast and dinner, respectively. Acarbose 50 mg decreased theCmaxof plasma insulin and C-peptide after breakfast and theCmaxof plasma glucose and C-peptide after dinner. The subjects who received TZQ did not report any abdominal adverse events.Conclusions. 3 tablets of TZQ have the same effects as the acarbose.

scholarly journals The effect of ispaghula (Fybogel and Metamucil) and guar gum on glucose tolerance in man

1984 ◽  
Vol 51 (3) ◽  
pp. 371-378 ◽  
Author(s):  
H. A. Jarjis ◽  
N. A. Blackburn ◽  
J. S. Redfern ◽  
N. W. Read
Keyword(s):  
Gastric Emptying ◽  
Glucose Tolerance ◽  
Plasma Glucose ◽  
Plasma Insulin ◽  
Guar Gum ◽  
Normal Subjects ◽  
Oral Glucose ◽  
Diabetic Patients ◽  
Glucose Plasma ◽  
Insulin Responses

1. The effects of incorporating Fybogel (3·5 and 7 g doses), Metamucil (7 g) or guar gum (2·5 and 14·5 g doses) in a drink containing 50 g glucose on plasma glucose, plasma insulin and gastric emptying were studied in thirty-eight normal volunteers. In addition, the effects of Fybogel (7 g) on glucose tolerance, plasma insulin and gastric emptying were measured in fourteen non-insulin-dependent diabetics.2. Both doses of guar gum significantly lowered plasma glucose and plasma insulin responses to the oral glucose load in normal subjects, although 14·5 g guar gum did not delay the half-time for gastric emptying.3. Neither Fybogel nor Metamucil had significant effects on plasma glucose responses in normal subjects. In addition, Fybogel (at either dose) had no significant effects on plasma insulin levels, or on gastric emptying in normal subjects or on plasma glucose and insulin responses in diabetic patients.4. The viscosity of ispaghula solutions (Fybogel) was lower than that of guar gum solutions.

Oral insulin in diabetic dogs

1991 ◽  
Vol 131 (2) ◽  
pp. 267-278 ◽  
Author(s):  
M. Saffran ◽  
J. B. Field ◽  
J. Peña ◽  
R. H. Jones ◽  
Y. Okuda
Keyword(s):  
Portal Vein ◽  
Plasma Flow ◽  
Plasma Glucose ◽  
Plasma Insulin ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Crystalline Insulin ◽  
Hepatic Glucose ◽  
Glucose Plasma ◽  
Oral Doses

ABSTRACT Bovine crystalline insulin, mixed with an absorption enhancer, was loaded by hand into gelatin capsules, which were then coated with an azopolymer designed to deliver the insulin in the upper colon. In 34 experiments with 14 pancreatectomized mongrel dogs of both sexes, the coated capsules were administered orally after a pre-dose period of 1 h. The dogs had cannulae in the portal vein, hepatic vein and femoral artery and Doppler flow probes on the portal vein and hepatic artery. Insulin and food were withdrawn the day before an experiment. Responses measured were plasma glucose, plasma insulin, hepatic glucose production rate, hepatic plasma flow rate and plasma glucagon-like immunoactivity (GLI). Control experiments, with capsules without insulin, produced small changes from 'pre-dose' values. Insulin-containing capsules, without the azopolymer coating, resulted in some early changes consistent with upper gastrointestinal absorption. Single oral doses (66 to 400 nmol/kg) of insulin in completely coated capsules produced peaks of portal plasma insulin and transient decreases in plasma glucose, hepatic glucose production, hepatic plasma flow and plasma GLI. The changes usually began 1·5–2 h after administration of a single dose, and lasted for up to 3 h, but were not significantly related to the dose of insulin. Multiple oral doses of insulin, given at 1·5-h intervals, resulted in multiple peaks of plasma insulin, a continuing dose-dependent fall in plasma glucose to near-euglycaemia with the highest dose, and profound decreases in hepatic glucose production and plasma GLI. These data demonstrate that insulin absorbed from the gastrointestinal tract causes changes in glucose metabolism in the diabetic dog that are consistent with the action of insulin primarily on the liver and that repeated oral doses are necessary to correct the hyperglycaemia. Journal of Endocrinology (1991) 131, 267–278

Insulin secretion and substrate homeostasis in prolonged hypothermia in rats

1988 ◽  
Vol 255 (6) ◽  
pp. R1035-R1040
Author(s):  
R. Hoo-Paris ◽  
M. L. Jourdan ◽  
L. C. Wang ◽  
R. Rajotte
Keyword(s):  
Insulin Secretion ◽  
Plasma Glucose ◽  
Low Temperatures ◽  
Plasma Insulin ◽  
Glucose Utilization ◽  
Exogenous Insulin ◽  
Metabolic Substrate ◽  
Endogenous Insulin ◽  
Dose Dependent Decrease ◽  
Dose Dependent

In hypothermia, impairment of metabolic substrate mobilization and utilization may be a factor limiting survival. By use of a newly developed technique, substrate profiles and their regulation by insulin were examined in hypothermic rats (body temperature 19 degrees C) over 24 h. Plasma glucose concentrations increased to approximately 300 mg/dl during cooling and remained high throughout the period of hypothermia. Free fatty acid (FFA) concentration was not altered during cooling or during the first 10 h of hypothermia (approximately 700 mu eq/l) but progressively decreased thereafter, reaching 420 mu eq/l by 20 h. Plasma insulin decreased dramatically during cooling and remained very low (9 +/- 2 microU/ml) during the whole period of hypothermia, reflecting the suppression of insulin secretion by isolated islets at low temperatures. To test he hypothesis that suppression of endogenous insulin secretion may hamper glucose utilization and thus limit survival in hypothermia, exogenous insulin was administered. At doses of 0.1, 0.5, and 1 U/kg intravenously, insulin slowly decreased plasma glucose and FFA. However, at 0.1 and 1 U/kg intraperitoneally, insulin resulted in a dose-dependent decrease in survival time in the hypothermic rat. It is possible that the antilipolytic effect of insulin may have outweighed any beneficial effect of improving glucose utilization in hypothermia.

Wetting and the physiological responses of grain-fed cattle in a heated environment

2004 ◽  
Vol 55 (3) ◽  
pp. 253 ◽  
Author(s):  
John B. Gaughan ◽  
M. Shane Davis ◽  
Terry L. Mader
Keyword(s):  
Heat Stress ◽  
Experimental Design ◽  
Rectal Temperature ◽  
Environmental Conditions ◽  
Dry Matter ◽  
Physiological Responses ◽  
Dry Matter Intake ◽  
Metabolic Responses ◽  
Hot Days ◽  
Carry Over

A controlled crossover experimental design was used to determine the effect of altered water sprinkling duration on heifers subjected to heat stress conditions. Heifers were subjected to 3 days of thermoneutral conditions followed by 3 days of hot conditions accompanied by water sprinkling between 1300 and 1500 h (HOT1–3). Then on the following 2 days (HOT4–5), environmental conditions remained similar, but 3 heifers were sprinkled between 1200 and 1600 h (WET) and 3 were not sprinkled (NONWET). This was followed by a 1-day period (HOT6) in which environmental conditions and sprinkling regimen were similar to HOT1–3. Rectal temperature (RT) was collected hourly, and respiration rate (RR) was monitored every 2 h on HOT Days 2, 4, 5, and 6. Dry matter intake and rate of eating were also determined. Sprinkling reduced RR and RT (P < 0.01) of all heifers during HOT1–3. During HOT4–5, WET heifers had lower (P < 0.05) RT than NONWET from 1300 to 700 h and lower RR from 1400 to 2000 h. Dry matter intake of NONWET heifers was reduced by 30.6% (P < 0.05) during HOT4–5 and by 51.2% on HOT6. On HOT4–5 the dry matter intakes of WET heifers were similar to intakes under thermoneutral conditions. During HOT6, RT was again reduced following sprinkling in all heifers. Comparison of RT and RR of NONWET and WET heifers on HOT1–3 v. HOT6 revealed that under similar environmental conditions, NONWET heifers had increased RT, partially due to carry-over from HOT4–5. However, NONWET heifers had 40% lower feed intake but tended to have lower RR on HOT6 v. HOT1–3. Only RR of WET heifers was greater on HOT6, possibly a result of switching from a 4-h back to a 2-h sprinkling period, while maintaining a 62% greater intake (5.80 v. 3.58 kg/day) than NONWET heifers during this time. Results suggest that inconsistent cooling regimens may increase the susceptibility of cattle to heat stress and elicit different physiological and metabolic responses.

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