INTRODUCTION: The aim of this study was to understand the effects of short-term glucocorticoid administration in healthy subjects. METHODS: Five healthy men received dexamethasone (8 mg/day) for 7 days. Vastus lateralis muscle biopsy and knee extension torque measurement were performed before and after administration. A large number of individual muscle fibers were dissected from the biopsy samples (pre-administration: n = 165, post-administration: n = 177). RESULTS: Maximal knee extension torque increased after administration (∼ 13%), whereas both type 1 and type 2A fibers had decreased cross-sectional area (type 1: ∼ 11%, type 2A: ∼ 17%), myosin loss (type 1: ∼ 18%, type 2A: ∼ 32%), and loss of specific force (type 1: ∼ 24%, type 2A: ∼ 33%), which were preferential for fast fibers. CONCLUSION: Short-term dexamethasone administration in healthy subjects elicits quantitative and qualitative adaptations of muscle fibers that precede (and may predict) the clinical appearance of myopathy in glucocorticoid-treated subjects.
INTRODUCTION: The aim of this study was to understand the effects of short-term glucocorticoid administration in healthy subjects. METHODS: Five healthy men received dexamethasone (8 mg/day) for 7 days. Vastus lateralis muscle biopsy and knee extension torque measurement were performed before and after administration. A large number of individual muscle fibers were dissected from the biopsy samples (pre-administration: n = 165, post-administration: n = 177). RESULTS: Maximal knee extension torque increased after administration (∼ 13%), whereas both type 1 and type 2A fibers had decreased cross-sectional area (type 1: ∼ 11%, type 2A: ∼ 17%), myosin loss (type 1: ∼ 18%, type 2A: ∼ 32%), and loss of specific force (type 1: ∼ 24%, type 2A: ∼ 33%), which were preferential for fast fibers. CONCLUSION: Short-term dexamethasone administration in healthy subjects elicits quantitative and qualitative adaptations of muscle fibers that precede (and may predict) the clinical appearance of myopathy in glucocorticoid-treated subjects.
Authors: Amy Y Sato; Danielle Richardson; Meloney Cregor; Hannah M Davis; Ernie D Au; Kevin McAndrews; Teresa A Zimmers; Jason M Organ; Munro Peacock; Lilian I Plotkin; Teresita Bellido Journal: Endocrinology Date: 2017-03-01 Impact factor: 4.736
Authors: Gabriel P Esteves; Bruna Caruso Mazzolani; Fabiana Infante Smaira; Elizabeth Silva Mendes; Gabriela Guimarães de Oliveira; Hamilton Roschel; Bruno Gualano; Rosa Maria R Pereira; Eimear Dolan Journal: Rheumatol Adv Pract Date: 2022-04-21
Authors: M A Minetto; C Caresio; M Salvi; V D'Angelo; N E Gorji; F Molinari; G Arnaldi; S Kesari; E Arvat Journal: J Endocrinol Invest Date: 2018-11-15 Impact factor: 4.256