Department of Anatomy, Faculty of Medicine, Jordan University of Science and Technology, Irbid, Jordan.
Université Paris-Saclay, UVSQ, Inserm, END-ICAP, 78000, Versailles, France.
Sci Rep. 2021 Jun 10;11(1):12301. doi: 10.1038/s41598-021-91854-4.
Oxidative and glycolytic muscle fibers differ in their ultrastructure, metabolism, and responses to physiological stimuli and pathological insults. We examined whether these fibers respond differentially to exogenous anabolic androgenic steroids (AASs) by comparing morphological and histological changes between the oxidative anterior latissimus dorsi (ALD) and glycolytic pectoralis major (PM) fibers in adult avian muscles. Adult female White Leghorn chickens (Gallus gallus) were randomly divided into five groups: a vehicle control and four mesterolone treatment groups (4, 8, 12, and 16 mg/kg). Mesterolone was administered orally every three days for four weeks. Immunocytochemical techniques and morphometric analyses were employed to measure the changes in muscle weight, fiber size, satellite cell (SC) composition, and number of myonuclei. Mesterolone increased both body and muscle weights and induced hypertrophy in glycolytic PM fibers but not in oxidative ALD fibers. Mesterolone induced SC proliferation in both muscles; however, the myonuclear accretion was noticeable only in the PM muscle. In both muscles, the collective changes maintained a constant myonuclear domain size and the changes were dose independent. In conclusion, mesterolone induced distinct dose-independent effects in avian oxidative and glycolytic skeletal muscle fibers; these findings might be clinically valuable in the treatment of age-related sarcopenia.
氧化型和糖酵解型肌纤维在超微结构、代谢以及对生理刺激和病理损伤的反应方面存在差异。我们通过比较成年禽类肌肉中氧化型前背阔肌（ALD）和糖酵解型胸大肌（PM）纤维的形态和组织学变化，来研究这些纤维对外源性合成代谢雄激素（AAS）是否存在不同的反应。成年雌性白来航鸡（Gallus gallus）被随机分为五组：对照组和 4、8、12 和 16mg/kg 美替诺龙治疗组。美替诺龙每三天口服一次，持续四周。免疫细胞化学技术和形态计量分析用于测量肌肉重量、纤维大小、卫星细胞（SC）组成和肌核数量的变化。美替诺龙增加了鸡的体重和肌肉重量，并诱导了糖酵解 PM 纤维的肥大，但对氧化型 ALD 纤维没有作用。美替诺龙诱导了两种肌肉中的 SC 增殖；然而，只有 PM 肌肉中出现了肌核堆积。在两种肌肉中，集体变化保持恒定的肌核域大小，且变化与剂量无关。总之，美替诺龙对禽类氧化型和糖酵解型骨骼肌纤维产生了明显的、与剂量无关的影响；这些发现可能对治疗与年龄相关的肌肉减少症具有临床价值。
