Glucagon and insulin regulate in vitro hepatic glycogenolysis in the axolotl Ambystoma mexicanum via changes in tissue cyclic AMP concentration
| Autor: | Frances Maher, P.A. Janssens |
|---|---|
| Rok vydání: | 1986 |
| Předmět: |
medicine.medical_specialty
Glycogenolysis IBMX Epinephrine medicine.medical_treatment Biology In Vitro Techniques Glucagon Ambystoma chemistry.chemical_compound Glycogen phosphorylase Endocrinology Internal medicine 1-Methyl-3-isobutylxanthine medicine Cyclic AMP Animals Insulin Phosphorylase a Phosphodiesterase inhibitor Glycogen Liver Glycogen Enzyme Activation Glucose chemistry Glycogenesis Animal Science and Zoology |
| Zdroj: | General and comparative endocrinology. 61(1) |
| ISSN: | 0016-6480 |
| Popis: | Glucagon increases the rate of glycogenolysis in in vitro cultures of hepatic tissue from the axolotl Ambystoma mexicanum. The hormone causes an increase in the concentration of cyclic AMP in the tissue which is followed by activation of glycogen phosphorylase and subsequent breakdown of glycogen and release of glucose from the tissue. Insulin counteracts the glycogenolytic effect of glucagon by inhibiting the increase in tissue cyclic AMP concentration brought about by glucagon. This inhibitory effect of insulin is not seen in the presence of the phosphodiesterase inhibitor IBMX and so it appears that the initial action of insulin is a stimulation of cyclic AMP phosphodiesterase activity which lowers the tissue concentration of cyclic AMP and so counters the actions of hormones that act by raising the tissue concentration of cyclic AMP. This model for the mode of action of insulin is supported by the finding that insulin also interferes with the glycogenolytic actions of adrenaline, a second hormone which acts by raising tissue cyclic AMP concentrations. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|