title: Importance of serotonin (5-HT) and its precursor l-tryptophan for homeostasis and function of skeletal muscle in rats. A morphological and endocrinological study.
abstract: Serotonin (5-HT) is a neurotransmitter, synthesized in serotonergic neurons of the central nervous system and in enterochromaffin cells of the gastrointestinal tract, which is involved in the regulation of several body functions, including muscle tissue development and growth and its contractile response. l-Tryptophan (l-Trp) is an essential amino acid and precursor of 5-HT. The aim of the present study was to better understand the mechanisms that govern neuroendocrine homeostasis of muscle tissue and emphasize the importance of a diet, complete in all its elements, referring specifically to the essential amino acids such as l-Trp, crucial in several neuroendocrine functions.We analyzed the possible consequences of l-Trp-free diet on 5-HT production and on skeletal muscle morphology and function in young female rats. We also evaluated the eventual alterations of hormone production such as growth hormone (GH), thyroid stimulating hormone (TSH) and thyroid hormones (T3 and T4) that control and regulate growth, metabolism and efficiency of the skeletal muscle. Our results showed a strong decrease of 5-HT, GH, TSH, T3 and T4 levels associated to a clear difference in body weight between experimental and control rats. Moreover, the muscle samples of experimental rats showed histological and ultrastructural alterations. These findings thus supported a strong link between l-Trp, serotonergic system, hormone secretion and morphology of skeletal muscle tissue and thus, the importance of a balanced daily diet.
authors: Department of Biomedical and Biotechnological Sciences, Human Anatomy and Histology Section, School of Medicine, University of Catania, Via S. Sofia 87, 95123 Catania, Italy. Electronic address: g.musumeci@unict.it.
authors: Giuseppe
authors: G
authors: Musumeci
authors: Department of Biomedical and Biotechnological Sciences, Human Anatomy and Histology Section, School of Medicine, University of Catania, Via S. Sofia 87, 95123 Catania, Italy.
authors: Rosa
authors: R
authors: Imbesi
authors: Department of Clinical and Experimental Medicine, Internal Medicine Division, University of Catania, Via S. Sofia 78, 95123 Catania, Italy.
authors: Francesca Maria
authors: FM
authors: Trovato
authors: Department of Biomedical and Biotechnological Sciences, Human Anatomy and Histology Section, School of Medicine, University of Catania, Via S. Sofia 87, 95123 Catania, Italy.
authors: Marta Anna
authors: MA
authors: Szychlinska
authors: Department of Biomedical and Biotechnological Sciences, Human Anatomy and Histology Section, School of Medicine, University of Catania, Via S. Sofia 87, 95123 Catania, Italy.
authors: Flavia Concetta
authors: FC
authors: Aiello
authors: Randall Division of Cell and Molecular Biophysics, King's College London, London, UK.
authors: Pietro
authors: P
authors: Buffa
authors: Department of Biomedical and Biotechnological Sciences, Human Anatomy and Histology Section, School of Medicine, University of Catania, Via S. Sofia 87, 95123 Catania, Italy.
authors: Paola
authors: P
authors: Castrogiovanni
mesh_terms: D000818:Animals; D005260:Female; D013006:Growth Hormone / Q000097:blood; D006706:Homeostasis; D018482:Muscle, Skeletal / Q000166:cytology / Q000502:physiology*; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D014364:Tryptophan / Q000097:blood*
chemical_list: D014284:Triiodothyronine; D012701:Serotonin; D014364:Tryptophan; D013972:Thyrotropin; D013006:Growth Hormone; D013974:Thyroxine
keywords: Diet; Histology; Hormone assays; Morphology; Muscles; Serotonin; l-Tryptophan