Mechanisms involved in catecholamine effect on glycogenolysis in catfish isolated hepatocytes

Brighenti, L; Ac, Puviani; Me, Gavioli; Ottolenghi, C

doi:10.1016/0016-6480(87)90239-5

Cited by 36 publications

(5 citation statements)

References 29 publications

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“…This fact is in agreement with two previous observations: 1) that glycogen content in catfish liver is also stable under the action of either fasting or catecholamine treatment (Ottolenghi et al 1981 ;Brighenti et al 1987b), both of which supposedly induce glycogenolysis, and 2) that glucagon-related peptides stimulate not only glycogenolysis but gluconeogenesis as well (Morata et al 1982;Mommsen et al 1987;Mommsen and Moon 1989). During each particular period of the fish life cycle, one or another metabolic pathway may be more enhanced.…”

Section: Discussionsupporting

confidence: 81%

Glycogenolytic action of glucagon-family peptides and epinephrine on catfish hepatocytes

Ottolenghi

Puviani

Gavioli

et al. 1989

Fish Physiol Biochem

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Glycogenolytic effects of salmon and mammalian glucagons, salmon glucagon-like peptide (GLP) and epinephrine were studied on liver cells isolated from catfish (Ictalurus melas). In spring and summer, salmo-glucagon (3×10(-10) to 3×10(-8) M) was more effective than its mammalian counterpart in the stimulation of glucose release and cAMP synthesis in hepatocytes. GLP was less potent as compared to both glucagons. γ-amylase activity was not affected by the treatment with either glucagon-family peptides or epinephrine.The comparison of the glycogenolytic effects of salmon glucagon to those of epinephrine reveals a greater potency of the latter hormone in the stimulation of cAMP synthesis, glycogen-phosphorylase activity and glucose release. Glycogen content in the liver cells was equally depleted after treatment with both of the two hormones.

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Section: Discussionsupporting

confidence: 81%

Glycogenolytic action of glucagon-family peptides and epinephrine on catfish hepatocytes

Ottolenghi

Puviani

Gavioli

et al. 1989

Fish Physiol Biochem

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“…The eel liver AC activity was responsive to both Epi and PE, the latter compound being less effective than the natural CA. Moreover, CA potently increased intracellular cAMP production also in eel hepatocytes, as already reported for other fish (5,31). The action of CA on the AC system could be ascribed to ␤-adrenoceptor occupation, because Pro, but not PNT, proved able to counteract the effects of Epi and PE.…”

Section: R1567supporting

confidence: 76%

Adenylyl cyclase activity and glucose release from the liver of the European eel,Anguilla anguilla

Fabbri

Barbin

Capuzzo

et al. 1998

American Journal of Physiology-Regulatory, Integrative and Comp

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The properties of adenylyl cyclase (AC) in liver membranes of the European eel ( Anguilla anguilla) and the involvement of cAMP in glucose release from isolated hepatocytes in response to catecholamines were studied. Basal enzyme activity seemed essentially unaffected by GTP, while a biphasic response to increasing nucleotide concentrations was obtained in the presence of epinephrine. Eel liver AC was dose-dependently stimulated by guanosine 5′- O-(3-thiotriphosphate) and inhibited by guanosine 5′- O-(2-thiodiphosphate). AC activity, intracellular cAMP levels, and glucose release from isolated hepatocytes were significantly enhanced by NaF, forskolin, epinephrine, and phenylephrine. The rise in cAMP production stimulated by catecholamines was counteracted by propranolol, but not by phentolamine. Catecholamine-induced glucose output was instead partially antagonized by both phentolamine and propranolol. Complete inhibition was obtained only by the simultaneous presence of the two adrenergic antagonists. Glucose release from the cells was induced by dibutyryl cAMP and by the calcium ionophore ionomycin. In summary, these data provide the first characterization of eel liver AC system and suggest a direct role for cAMP in the catecholamine-dependent glucose output. Furthermore, the involvement of calcium ions in this cellular response is hypothesized.

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“…This is generally accepted to be mainly mediated by β-adrenoceptor stimulated glycogenolysis and β-adrenoceptor inhibited glycolysis in the liver (Birnbaum et al, 1976;Janssens and Lowrey, 1987;Mommsen et al, 1988;Wright et al, 1989;Reid et al, 1992). However, the presence of stimulatory α-adrenoceptors has been demonstrated in vitro (Brighenti et al, 1987;Moon et al, 1993;Fabbri et al, 1995Fabbri et al, , 1999. Although the fact that isoprenaline completely mimicked the effect of noradrenaline also suggests that in African catfish hyperglycemia was mainly mediated by β-adrenoceptors, our data do not allow differentiation between β-and α-adrenoceptor effects.…”

Section: Glucosecontrasting

confidence: 61%

“…The results from this study (see Fig.·5) and from Van den Thillart et al (2001) suggest functional selectivity of these antagonists. These data should be treated cautiously, however, as several studies indicate a possible discrepancy in the characteristics of adrenergic ligands between mammals and teleost (Brighenti et al, 1987;Moon and Mommsen, 1990;Fabbri et al, 1992). Additional experiments with African catfish hepatocytes using both pharmacological and molecular tools will identify the subtype of the hepatic β-adrenoceptor in this species.…”

Section: Glucosementioning

confidence: 99%

Beta-adrenergic control of plasma glucose and free fatty acid levels in the air-breathing African catfishClarias gariepinusBurchell 1822

Heeswijk

Vianen

Thillart

et al. 2005

Journal of Experimental Biology

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In several water-breathing fish species, β-adrenergic receptor stimulation by noradrenaline leads to a decrease in plasma free fatty acid (FFA) levels, as opposed to an increase in air-breathing mammals. We hypothesised that this change in adrenergic control is related to the mode of breathing. Therefore, cannulated air-breathing African catfish were infused for 90·min with noradrenaline or with the nonselective β-agonist, isoprenaline. To identify the receptor type involved, a bolus of either a selective β 1 -antagonist (atenolol) or a selective β 2 -antagonist (ICI 118,551) was injected 15·min prior to the isoprenaline infusion. Both noradrenaline and isoprenaline led to an expected rise in glucose concentration. Isoprenaline combined with both the β 1 -and β 2 -antagonist led to higher glucose concentrations than isoprenaline alone. This could indicate the presence of a stimulatory β-adrenoceptor different from β 1 and β 2 -adrenoceptors; these two receptors thus seemed to mediate a reduction in plasma glucose concentration. Both noradrenaline and isoprenaline led to a significant decrease in FFA concentration. Whereas the β 1 -antagonist had no effect, the β 2 -antagonist reduced the decrease in FFA concentration, indicating the involvement of β 2 -adrenoceptors. It is concluded that the air-breathing African catfish reflects water-breathing fish in the adrenergic control of plasma FFA and glucose levels.

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Mechanisms involved in catecholamine effect on glycogenolysis in catfish isolated hepatocytes

Cited by 36 publications

References 29 publications

Glycogenolytic action of glucagon-family peptides and epinephrine on catfish hepatocytes

Glycogenolytic action of glucagon-family peptides and epinephrine on catfish hepatocytes

Adenylyl cyclase activity and glucose release from the liver of the European eel,Anguilla anguilla

Beta-adrenergic control of plasma glucose and free fatty acid levels in the air-breathing African catfishClarias gariepinusBurchell 1822

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