Beta-hydroxy-beta-methylbutyrate (HMB) is a leucine metabolite with protein anabolic effect. The aim of the study was to examine the role of exogenous HMB on leucine and protein metabolism in whole body and selected tissues. Rats were administered by HMB (0.1 g/kg b.w.) or by saline. The parameters of whole-body protein metabolism were evaluated 24 h later using L-[1-14C]leucine and L-[3,4,5-3H]phenylalanine. Changes in proteasome dependent proteolysis and protein synthesis were determined according the "chymotrypsin-like" enzyme activity and labeled leucine and phenylalanine incorporation into the protein. A decrease in leucine clearance and whole-body protein turnover (i.e., a decrease in whole-body proteolysis and protein synthesis) was observed in HMB treated rats. Proteasome-dependent proteolysis decreased significantly in skeletal muscle, changes in heart, liver, jejunum, colon, kidney, and spleen were insignificant. Decrease in protein synthesis was observed in the heart, colon, kidney, and spleen, while an increase was observed in the liver. There were no significant changes in leucine oxidation. We conclude that protein anabolic effect of HMB in skeletal muscle is related to inhibition of proteolysis in proteasome. Alterations in protein synthesis in visceral tissues may affect several important functions and the metabolic status of the whole body.

• MeSH
• financování organizované MeSH
• játra metabolismus   účinky léků   MeSH
• kosterní svaly metabolismus   účinky léků   MeSH
• krysa rodu rattus MeSH
• ledviny metabolismus   účinky léků   MeSH
• myokard metabolismus   MeSH
• N-acetyltransferasa aminokyselin metabolismus   MeSH
• potkani Wistar MeSH
• proteiny metabolismus   MeSH
• slezina metabolismus   účinky léků   MeSH
• srdce účinky léků   MeSH
• střeva metabolismus   účinky léků   MeSH
• valeráty farmakologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH