PMID- 37863411
OWN - NLM
STAT- MEDLINE
DCOM- 20231123
LR  - 20231123
IS  - 1878-5867 (Electronic)
IS  - 0039-128X (Linking)
VI  - 200
DP  - 2023 Dec
TI  - Mechanism of skeletal muscle atrophy by muscle fiber types in male rats under 
      long-term fasting stress.
PG  - 109328
LID - S0039-128X(23)00156-3 [pii]
LID - 10.1016/j.steroids.2023.109328 [doi]
AB  - Fasting induces metabolic changes in muscles, which are differentiated by muscle 
      fiber type. In this study, the mechanism of fasting-induced muscle atrophy in 
      rats was examined to determine the differences between muscle fiber types in 
      energy production. Fasting for 96 h did not alter the weight of the soleus (SOL), 
      a fiber type I muscle, but did significantly reduce the weight of gastrocnemius 
      (GM), a fiber type II muscle. GM, SOL and blood pregnenolone and testosterone 
      levels decreased under fasting, which induced energy deprivation, whereas 
      corticosterone (CORT) levels significantly increased. However, the expression of 
      3beta-HSD and P45011beta in GM was unaffected by fasting. The decrease in GM weight may 
      be due to decreased levels of testosterone and reduced synthesis of mammalian 
      target of rapamycin (mTOR). Significant increases in CORT both GM and SOL were 
      associated with increases in the amount of branched-chain amino acids available 
      for energy production. However, decreased levels of mTOR and IGF1 and increased 
      levels of CORT and IL-6 in SOL suggest that GM proteolysis was followed by SOL 
      proteolysis for additional energy production. In conclusion, IGF1 levels 
      decreased significantly in SOL, whereas those of IL-6 significantly increased in 
      SOL and blood but decreased in GM. Blood branched-chain amino acids (BCAA) levels 
      were unaffected due to fasting, whereas an increase was noted in the levels of 
      BCAA in GM and SOL. These results show that fasting for 96 h restricts energy 
      supply, producing fast-twitch muscle atrophy followed by slow-twitch muscle 
      atrophy.
CI  - Copyright (c) 2023 Elsevier Inc. All rights reserved.
FAU - Ieko, Takahiro
AU  - Ieko T
AD  - Laboratory of Veterinary Biochemistry, Department of Veterinary Medicine, Rakuno 
      Gakuen University, Hokkaido 069-8501, Japan.
FAU - Fujiki, Jumpei
AU  - Fujiki J
AD  - Laboratory of Veterinary Biochemistry, Department of Veterinary Medicine, Rakuno 
      Gakuen University, Hokkaido 069-8501, Japan.
FAU - Hasegawa, Yasuhiro
AU  - Hasegawa Y
AD  - Laboratory of Meat Science, Department of Food Science and Human Wellness, Rakuno 
      Gakuen University, Hokkaido 069-8501, Japan.
FAU - Iwasaki, Tomohito
AU  - Iwasaki T
AD  - Laboratory of Meat Science, Department of Food Science and Human Wellness, Rakuno 
      Gakuen University, Hokkaido 069-8501, Japan.
FAU - Iwano, Hidetomo
AU  - Iwano H
AD  - Laboratory of Veterinary Biochemistry, Department of Veterinary Medicine, Rakuno 
      Gakuen University, Hokkaido 069-8501, Japan.
FAU - Maeda, Naoyuki
AU  - Maeda N
AD  - Laboratory of Veterinary Biochemistry, Department of Veterinary Medicine, Rakuno 
      Gakuen University, Hokkaido 069-8501, Japan; Laboratory of Meat Science, 
      Department of Food Science and Human Wellness, Rakuno Gakuen University, Hokkaido 
      069-8501, Japan. Electronic address: n-maeda@rakuno.ac.jp.
LA  - eng
PT  - Journal Article
DEP - 20231018
PL  - United States
TA  - Steroids
JT  - Steroids
JID - 0404536
RN  - 0 (Interleukin-6)
RN  - 0 (Amino Acids, Branched-Chain)
RN  - 3XMK78S47O (Testosterone)
RN  - EC 2.7.11.1 (TOR Serine-Threonine Kinases)
SB  - IM
MH  - Rats
MH  - Male
MH  - Animals
MH  - *Interleukin-6/metabolism
MH  - *Muscle Fibers, Skeletal/metabolism
MH  - Muscular Atrophy/metabolism
MH  - Muscle, Skeletal/metabolism
MH  - Fasting
MH  - Amino Acids, Branched-Chain/metabolism
MH  - Testosterone/metabolism
MH  - TOR Serine-Threonine Kinases/metabolism
MH  - Mammals/metabolism
OTO - NOTNLM
OT  - And fasting stress
OT  - Branched-chain amino acids
OT  - Corticosterone
OT  - Interleukin-6
OT  - Mammalian target of rapamycin
COIS- Declaration of Competing Interest The authors declare that they have no known 
      competing financial interests or personal relationships that could have appeared 
      to influence the work reported in this paper.
EDAT- 2023/10/21 05:42
MHDA- 2023/11/23 06:42
CRDT- 2023/10/20 19:32
PHST- 2023/06/25 00:00 [received]
PHST- 2023/10/04 00:00 [revised]
PHST- 2023/10/17 00:00 [accepted]
PHST- 2023/11/23 06:42 [medline]
PHST- 2023/10/21 05:42 [pubmed]
PHST- 2023/10/20 19:32 [entrez]
AID - S0039-128X(23)00156-3 [pii]
AID - 10.1016/j.steroids.2023.109328 [doi]
PST - ppublish
SO  - Steroids. 2023 Dec;200:109328. doi: 10.1016/j.steroids.2023.109328. Epub 2023 Oct 
      18.