Importance of basal glucagon in maintaining hepatic glucose production during a prolonged fast in conscious dogs
| Autor: | R. T. Frizzell, David H. Wasserman, Alan D. Cherrington, Phillip E. Williams, G. K. Hendrick, J. B. Jaspan, D. B. Lacy |
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| Rok vydání: | 1992 |
| Předmět: |
Glycerol
Male medicine.medical_specialty Time Factors Physiology Endocrinology Diabetes and Metabolism Biology Carbohydrate metabolism Glucagon chemistry.chemical_compound Catecholamines Dogs Physiology (medical) Internal medicine medicine Animals Lactic Acid Pancreatic hormone Alanine Glycogen Gluconeogenesis Fasting Glucagon Deficiency Hormones Endocrinology Somatostatin Glucose chemistry Basal (medicine) Liver Lactates Female hormones hormone substitutes and hormone antagonists |
| Zdroj: | The American journal of physiology. 263(3 Pt 1) |
| ISSN: | 0002-9513 |
| Popis: | We undertook studies in conscious dogs to assess the role of basal glucagon in stimulating glucose production after a 7-day fast. Two protocols consisting of a 40-min basal period (-40 to 0 min), and a 180-min test period (0-180 min) were used. During the test period of the first protocol (hormone replacement; n = 4), somatostatin was infused (0.8 micrograms.kg-1.min-1) along with basal intraportal replacement amounts of insulin and glucagon, whereas in the second protocol (glucagon deficiency; n = 5), somatostatin plus insulin alone were infused. Glucose production and gluconeogenesis were measured using tracer and arteriovenous difference techniques. Plasma insulin levels were similar during the test period in both protocols (6 +/- 1 microU/ml). The plasma immunoreactive glucagon level in the control protocol averaged 50 +/- 8 pg/ml, whereas in the glucagon-deficiency protocol the level fell from 50 +/- 8 to 29 +/- 8 pg/ml (P less than 0.05). The plasma glucose level and the rate of glucose production were unchanged during bihormonal replacement. During glucagon deficiency the plasma glucose level was held constant at 100 +/- 4 mg/dl by glucose infusion. Tracer-determined endogenous glucose production fell from 1.8 +/- 0.1 to 1.0 +/- 0.1 mg.kg-1.min-1 by 30 min (P less than 0.05). After 3 h of glucagon deficiency, gluconeogenic conversion of alanine to glucagon was reduced 40% and the hepatic fractional extraction of alanine was reduced by 45%. The efficiency of the gluconeogenic process within the liver was not altered by glucagon deficiency.(ABSTRACT TRUNCATED AT 250 WORDS) |
| Databáze: | OpenAIRE |
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