Tags

Type your tag names separated by a space and hit enter

Alanyl-glutamine prevents muscle atrophy and glutamine synthetase induction by glucocorticoids.
Am J Physiol. 1996 Nov; 271(5 Pt 2):R1165-72.AJ

Abstract

The aims of this work were to establish whether glutamine infusion via alanyl-glutamine dipeptide provides effective therapy against muscle atrophy from glucorticoids and whether the glucocorticoid induction of glutamine synthetase (GS) is downregulated by dipeptide supplementation. Rats were given hydrocortisone 21-acetate or the dosing vehicle and were infused with alanine (AA) or alanyl-glutamine (AG) at the same concentrations and rates (1.15 mumol.min-1.100 g body wt-1, 0.75 ml/h) for 7 days. Compared with AA infusion in hormone-treated animals, AG infusion prevented total body and fast-twitch muscle mass losses by over 70%. Glucocorticoid treatment did not reduce muscle glutamine levels. Higher serum glutamine was found in the AG-infused (1.72 +/- 0.28 mumol/ml) compared with the AA-infused group (1.32 +/- 0.06 mumol/ml), but muscle glutamine concentrations were not elevated by AG infusion. Following glucocorticoid injections, GS enzyme activity was increased by two- to threefold in plantaris, fast-twitch white (superficial quadriceps), and fast-twitch red (deep quadriceps) muscle/fiber types of the AA group. Similarly, GS mRNA was elevated by 3.3- to 4.1-fold in these same muscles of hormone-treated, AA-infused rats. AG infusion diminished glucocorticoid effects on GS enzyme activity to 52-65% and on GS mRNA to 31-37% of the values with AA infusion. These results provide firsthand evidence of atrophy prevention from a catabolic state using glutamine in dipeptide form. Despite higher serum and muscle alanine levels with AA infusion than with AG infusion, alanine alone is not a sufficient stimulus to counteract muscle atrophy. The AG-induced muscle sparing is accompanied by diminished expression of a glucocorticoid-inducible gene in skeletal muscle. However, glutamine regulation of GS appears complex and may involve more regulators than muscle glutamine concentration alone.

Authors+Show Affiliations

School of Kinesiology, University of Illinois at Chicago 60608-1516, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

8945950

Citation

Hickson, R C., et al. "Alanyl-glutamine Prevents Muscle Atrophy and Glutamine Synthetase Induction By Glucocorticoids." The American Journal of Physiology, vol. 271, no. 5 Pt 2, 1996, pp. R1165-72.
Hickson RC, Wegrzyn LE, Osborne DF, et al. Alanyl-glutamine prevents muscle atrophy and glutamine synthetase induction by glucocorticoids. Am J Physiol. 1996;271(5 Pt 2):R1165-72.
Hickson, R. C., Wegrzyn, L. E., Osborne, D. F., & Karl, I. E. (1996). Alanyl-glutamine prevents muscle atrophy and glutamine synthetase induction by glucocorticoids. The American Journal of Physiology, 271(5 Pt 2), R1165-72.
Hickson RC, et al. Alanyl-glutamine Prevents Muscle Atrophy and Glutamine Synthetase Induction By Glucocorticoids. Am J Physiol. 1996;271(5 Pt 2):R1165-72. PubMed PMID: 8945950.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Alanyl-glutamine prevents muscle atrophy and glutamine synthetase induction by glucocorticoids. AU - Hickson,R C, AU - Wegrzyn,L E, AU - Osborne,D F, AU - Karl,I E, PY - 1996/11/1/pubmed PY - 1996/11/1/medline PY - 1996/11/1/entrez SP - R1165 EP - 72 JF - The American journal of physiology JO - Am J Physiol VL - 271 IS - 5 Pt 2 N2 - The aims of this work were to establish whether glutamine infusion via alanyl-glutamine dipeptide provides effective therapy against muscle atrophy from glucorticoids and whether the glucocorticoid induction of glutamine synthetase (GS) is downregulated by dipeptide supplementation. Rats were given hydrocortisone 21-acetate or the dosing vehicle and were infused with alanine (AA) or alanyl-glutamine (AG) at the same concentrations and rates (1.15 mumol.min-1.100 g body wt-1, 0.75 ml/h) for 7 days. Compared with AA infusion in hormone-treated animals, AG infusion prevented total body and fast-twitch muscle mass losses by over 70%. Glucocorticoid treatment did not reduce muscle glutamine levels. Higher serum glutamine was found in the AG-infused (1.72 +/- 0.28 mumol/ml) compared with the AA-infused group (1.32 +/- 0.06 mumol/ml), but muscle glutamine concentrations were not elevated by AG infusion. Following glucocorticoid injections, GS enzyme activity was increased by two- to threefold in plantaris, fast-twitch white (superficial quadriceps), and fast-twitch red (deep quadriceps) muscle/fiber types of the AA group. Similarly, GS mRNA was elevated by 3.3- to 4.1-fold in these same muscles of hormone-treated, AA-infused rats. AG infusion diminished glucocorticoid effects on GS enzyme activity to 52-65% and on GS mRNA to 31-37% of the values with AA infusion. These results provide firsthand evidence of atrophy prevention from a catabolic state using glutamine in dipeptide form. Despite higher serum and muscle alanine levels with AA infusion than with AG infusion, alanine alone is not a sufficient stimulus to counteract muscle atrophy. The AG-induced muscle sparing is accompanied by diminished expression of a glucocorticoid-inducible gene in skeletal muscle. However, glutamine regulation of GS appears complex and may involve more regulators than muscle glutamine concentration alone. SN - 0002-9513 UR - https://www.unboundmedicine.com/medline/citation/8945950/Alanyl_glutamine_prevents_muscle_atrophy_and_glutamine_synthetase_induction_by_glucocorticoids_ L2 - https://journals.physiology.org/doi/10.1152/ajpregu.1996.271.5.R1165?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -