Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/8243
Title: Muscle protein waste in tumor-bearing rats is effectively antagonized by a beta 2-adrenergic agonist (clenbuterol). Role of the ATP-ubiquitin-dependent proteolytic pathway.
Author: Costelli, Paola
García Martínez, Celia
Llovera i Tomàs, Marta
Carbó Carbó, Neus
López-Soriano, Francisco J.
Agell i Jané, Neus
Tessitore, Luciana
Baccino, Francesco M.
Argilés Huguet, Josep Ma.
Keywords: Tumors
Ubiquitina
Metabolisme de proteïnes
Caquèxia
Clenbuterol
Tumor
Protein turnover
Cachexia
Ubiquitin
Issue Date: 1995
Publisher: American Society for Clinical Investigation
Abstract: Tissue protein hypercatabolism (TPH) is a most important feature in cancer cachexia, particularly with regard to the skeletal muscle. The rat ascites hepatoma Yoshida AH-130 is a very suitable model system for studying the mechanisms involved in the processes that lead to tissue depletion, since it induces in the host a rapid and progressive muscle waste mainly due to TPH (Tessitore, L., G. Bonelli, and F. M. Baccino. 1987. Biochem. J. 241:153-159). Detectable plasma levels of tumor necrosis factor-alpha associated with marked perturbations in the hormonal homeostasis have been shown to concur in forcing metabolism into a catabolic setting (Tessitore, L., P. Costelli, and F. M. Baccino. 1993. Br. J. Cancer. 67:15-23). The present study was directed to investigate if beta 2-adrenergic agonists, which are known to favor skeletal muscle hypertrophy, could effectively antagonize the enhanced muscle protein breakdown in this cancer cachexia model. One such agent, i.e., clenbuterol, indeed largely prevented skeletal muscle waste in AH-130-bearing rats by restoring protein degradative rates close to control values. This normalization of protein breakdown rates was achieved through a decrease of the hyperactivation of the ATP-ubiquitin-dependent proteolytic pathway, as previously demonstrated in our laboratory (Llovera, M., C. García-Martínez, N. Agell, M. Marzábal, F. J. López-Soriano, and J. M. Argilés. 1994. FEBS (Fed. Eur. Biochem. Soc.) Lett. 338:311-318). By contrast, the drug did not exert any measurable effect on various parenchymal organs, nor did it modify the plasma level of corticosterone and insulin, which were increased and decreased, respectively, in the tumor hosts. The present data give new insights into the mechanisms by which clenbuterol exerts its preventive effect on muscle protein waste and seem to warrant the implementation of experimental protocols involving the use of clenbuterol or alike drugs in the treatment of pathological states involving TPH, particularly in skeletal muscle and heart, such as in the present model of cancer cachexia.
Note: Reproducció del document publicat a http://dx.doi.org/10.1172/JCI117929
It is part of: Journal of Clinical Investigation, 1995, vol. 95, núm. 5, p. 2367-2372.
URI: http://hdl.handle.net/2445/8243
ISSN: 0021-9738
Appears in Collections:Articles publicats en revistes (Bioquímica i Fisiologia)
Articles publicats en revistes (Biomedicina)
Articles publicats en revistes (Patologia i Terapèutica Experimental)

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