Impact of the calcium form of β-hydroxy-β-methylbutyrate upon human skeletal muscle protein metabolism.

摘要: Summary Background & aims β-hydroxy-β-methylbutyrate (HMB) is purported as a key nutritional supplement for the preservation of muscle mass in health, disease and an ergogenic aid exercise. Of two available forms HMB (calcium (Ca-HMB) salt or free acid (FA-HMB)) – differences plasma bioavailability have been reported. We previously reported that ∼3 g oral FA-HMB increased protein synthesis (MPS) reduced breakdown (MPB). The objective present study was to quantify metabolism responses Ca-HMB. Methods Eight healthy young males received primed constant infusion 1,2 13 C 2 leucine H 5 phenylalanine assess MPS (by tracer incorporation myofibrils) MPB (via arterio-venous (A-V) dilution) at baseline following provision Ca-HMB; anabolic catabolic (MPB) signalling assessed via immunoblotting. Results Ca-HMB led significant rapid ( p −1 , Ca-HMB: 5.2 ± 0.8 μmol Phe per leg min Conclusions These findings support pro-anabolic properties mTORc1, show despite proposed bioavailability, provides comparable stimulation suppression MPB, FA-HMB, further supporting its use pharmaconutrient modulation mass.