Acute effect of epinephrine on muscle proteolysis in perfused rat hindquarters

Kadowaki, Motoni; Kamata, Taito; Noguchi, Tadashi

doi:10.1152/ajpendo.1996.270.6.e961

Cited by 10 publications

(8 citation statements)

References 20 publications

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“…The data of the present work clearly show that catecholamines exert an inhibitory action on proteolysis in rat isolated skeletal muscle. The epinephrine-induced reduction in the rate of protein breakdown in isolated muscles (ϳ15-20%) was similar to that observed after epinephrine infusion in humans (30), in rat perfused hindlimb (11), and in muscle microdialysis experiments (28). An inhibitory action of catecholamines on skeletal muscle proteolysis was also suggested in a recent study from this laboratory (20) showing that rates of protein degradation in isolated muscles increase after acute chemical sympathectomy induced by guanethidine.…”

Section: Effect Of Dbcamp and Ibmx On Muscle Proteolysissupporting

confidence: 78%

Role of adrenoceptors and cAMP on the catecholamine-induced inhibition of proteolysis in rat skeletal muscle

Navegantes

Resano

Migliorini

et al. 2000

American Journal of Physiology-Endocrinology and Metabolism

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The role of adrenoceptor subtypes and of cAMP on rat skeletal muscle proteolysis was investigated using a preparation that maintains tissue glycogen stores and metabolic activity for several hours. In both soleus and extensor digitorum longus (EDL) muscles, proteolysis decreased by 15-20% in the presence of equimolar concentrations of epinephrine, isoproterenol, a nonselective beta-agonist, or clenbuterol, a selective beta(2)-agonist. Norepinephrine also reduced proteolysis but less markedly than epinephrine. No change in proteolysis was observed when muscles were incubated with phenylephrine, a nonselective alpha-agonist. The decrease in the rate of protein degradation induced by 10(-4) M epinephrine was prevented by 10(-5) M propranolol, a nonselective beta-antagonist, and by 10(-5) M ICI 118.551, a selective beta(2)-antagonist. The antiproteolytic effect of epinephrine was not inhibited by prazosin or yohimbine (selective alpha(1)-and alpha(2)-antagonists, respectively) or by atenolol, a selective beta(1)-antagonist. Dibutyryl cAMP and isobutylmethylxanthine reduced proteolysis in both soleus and EDL muscles. The data suggest that catecholamines exert an inhibitory control of skeletal muscle proteolysis, probably mediated by beta(2)-adrenoceptors, with the participation of a cAMP-dependent pathway.

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Section: Effect Of Dbcamp and Ibmx On Muscle Proteolysissupporting

confidence: 78%

Role of adrenoceptors and cAMP on the catecholamine-induced inhibition of proteolysis in rat skeletal muscle

Navegantes

Resano

Migliorini

et al. 2000

American Journal of Physiology-Endocrinology and Metabolism

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“…In agreement with this suggestion, we have found that both epinephrine and norepinephrine, added in vitro, reduce the rate of protein degradation in normal rat soleus and extensor digitorum longus (EDL) by approximately 15-20% (15). This view is consistent with the finding that infusion of epinephrine in muscle microdialysis experiments (16), in perfused rat hindquarters (17) and in humans (18) induces a rapid and similar 20% decrease in protein degradation.…”

Section: Introductionsupporting

confidence: 91%

The inhibitory role of sympathetic nervous system in the Ca2+-dependent proteolysis of skeletal muscle

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Baviera

Kettelhut

2009

Braz J Med Biol Res

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Mammalian cells contain several proteolytic systems to carry out the degradative processes and complex regulatory mechanisms to prevent excessive protein breakdown. Among these systems, the Ca 2+ -activated proteolytic system involves the cysteine proteases denoted calpains, and their inhibitor, calpastatin. Despite the rapid progress in molecular research on calpains and calpastatin, the physiological role and regulatory mechanisms of these proteins remain obscure. Interest in the adrenergic effect on Ca 2+ -dependent proteolysis has been stimulated by the finding that the administration of β 2 -agonists induces muscle hypertrophy and prevents the loss of muscle mass in a variety of pathologic conditions in which calpains are activated. This review summarizes evidence indicating that the sympathetic nervous system produces anabolic, protein-sparing effects on skeletal muscle protein metabolism. Studies are reviewed, which indicate that epinephrine secreted by the adrenal medulla and norepinephrine released from adrenergic terminals have inhibitory effects on Ca 2+ -dependent protein degradation, mainly in oxidative muscles, by increasing calpastatin levels. Evidence is also presented that this antiproteolytic effect, which occurs under both basal conditions and in stress situations, seems to be mediated by β 2 -and β 3 -adrenoceptors and cAMP-dependent pathways. The understanding of the precise mechanisms by which catecholamines promote muscle anabolic effects may have therapeutic value for the treatment of muscle-wasting conditions and may enhance muscle growth in farm species for economic and nutritional purposes.

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“…36). Some of these have been based on ex vivo proteolysis experiments performed with prepubertal rat muscles (12,26,28,32,37,47,50). Here we found that ␤-adrenergic agonists isoproterenol (nonselective) and formoterol (␤ 2 -selective) also reduced proteolysis of adult rat skeletal muscle by 12-20%.…”

Section: Discussionmentioning

confidence: 57%

The lumbrical muscle: a novel in situ system to evaluate adult skeletal muscle proteolysis and anticatabolic drugs for therapeutic purposes

Bergantin

Figueiredo

Godinho

2011

Journal of Applied Physiology

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Bergantin LB, Figueiredo LB, Godinho RO. The lumbrical muscle: a novel in situ system to evaluate adult skeletal muscle proteolysis and anticatabolic drugs for therapeutic purposes. J Appl Physiol 111: 1710 -1718, 2011. First published September 15, 2011 doi:10.1152/japplphysiol.00586.2011.-The molecular regulation of skeletal muscle proteolysis and the pharmacological screening of anticatabolic drugs have been addressed by measuring tyrosine release from prepubertal rat skeletal muscles, which are thin enough to allow adequate in vitro diffusion of oxygen and substrates. However, the use of muscle at accelerated prepubertal growth has limited the analysis of adult muscle proteolysis or that associated with aging and neurodegenerative diseases. Here we established the adult rat lumbrical muscle (4/hindpaw; 8/rat) as a new in situ experimental model for dynamic measurement of skeletal muscle proteolysis. By incubating lumbrical muscles attached to their individual metatarsal bones in Tyrode solution, we showed that the muscle proteolysis rate of adult and aged rats (3-4 to 24 mo old) is 45-25% of that in prepubertal animals (1 mo old), which makes questionable the usual extrapolation of proteolysis from prepubertal to adult/senile muscles. While acute mechanical injury or 1-to 7-day denervation increased tyrosine release from adult lumbrical muscle by up to 60%, it was reduced by 20 -28% after 2-h incubation with ␤-adrenoceptor agonists, forskolin or phosphodiesterase inhibitor IBMX. Using inhibitors of 26S-proteasome (MG132), lysosome (methylamine), or calpain (E64/leupeptin) systems, we showed that ubiquitin-proteasome is accountable for 40 -50% of total lumbrical proteolysis of adult, middle-aged, and aged rats. In conclusion, the lumbrical model allows the analysis of muscle proteolysis rate from prepubertal to senile rats. By permitting eight simultaneous matched measurements per rat, the new model improves similar protocols performed in paired extensor digitorum longus (EDL) muscles from prepubertal rats, optimizing the pharmacological screening of drugs for anticatabolic purposes.

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Acute effect of epinephrine on muscle proteolysis in perfused rat hindquarters

Cited by 10 publications

References 20 publications

Role of adrenoceptors and cAMP on the catecholamine-induced inhibition of proteolysis in rat skeletal muscle

Role of adrenoceptors and cAMP on the catecholamine-induced inhibition of proteolysis in rat skeletal muscle

The inhibitory role of sympathetic nervous system in the Ca2+-dependent proteolysis of skeletal muscle

The lumbrical muscle: a novel in situ system to evaluate adult skeletal muscle proteolysis and anticatabolic drugs for therapeutic purposes

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