Alteration of metabolic characteristics on the masseter muscle fiber of unilateral chewing rats and its adenosine monophosphate activated protein kinase regulatory mechanism.

Andi Shi; Lin Zeng; Jing Liu

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Alteration of metabolic characteristics on the masseter muscle fiber of unilateral chewing rats and its adenosine monophosphate activated protein kinase regulatory mechanism.

VernacularTitle:偏侧咀嚼致大鼠咬肌肌纤维代谢特征改变及其腺苷酸活化蛋白激酶调节机制
Author: Andi SHI ¹ ; Lin ZENG ¹ ; Jing LIU ²
Author Information

1. College of Stomatology, Jinan University, Guangzhou 510632, China.
2. Dept. of Prosthodontics, College of Stomatology, Jinan University, Guang-zhou 510632, China
Publication Type:Journal Article
Keywords: adenosine monophosphate activated protein kinase; nicotine adenine dinucleotide tetrazolium reductase; oxidative metabolism; unilateral chewing
MeSH: AMP-Activated Protein Kinases; Adenosine Monophosphate; Animals; Masseter Muscle; Mastication; Molar; Protein Kinases; Rats; Tooth Extraction
From: West China Journal of Stomatology 2017;35(3):258-263
CountryChina
Language:Chinese
Abstract:
OBJECTIVEThis study aims to determine the influence of unilateral chewing on metabolic characteristics of masseter muscle fibers in rats and the regulatory effect of an adenosine monophosphate activated protein kinase (AMPK) signal pathway on metabolism.
METHODSRats were submitted to exodontia of all the right maxillary molars and divided into 2, 4, 6, and 8 weeks groups, and corresponding control groups were set as well. Sections were stained by nicotine adenine dinucleotide tetrazolim reductase(NADH-TRase) to demonstrate the types, proportion, and density of masseter muscle fibers. AMPKα1 and p-AMPK(Thr172) levels in bilateral masseter muscles were detected by Western blot.
RESULTSIn the 2-week group, the percentage of dark fibers augmented in the ipsilateral side, whereas the percentage of intermediary fibers in the contralateral side was increased accompanied by a decrease of light fibers, compared with the control group (P<0.05). The percentage of dark fibers was increased in the bilateral sides, whereas the percentage of dark fiber in the ipsilateral sides surpassed that of the contralateral sides in the 4, 6, and 8-week groups. The percentage of intermediary fibers was decreased in the bilateral sides in the 6 and 8-week groups (P<0.05). The percentage of light fibers was reduced in the ipsilateral sides in the 8-week group, whereas no alteration was observed in contralateral sides (P>0.05). In the ipsilateral sides, p-AMPK (Thr172)/AMPKα1 levels were increased in the 2 and 4-week groups (P<0.05), whereas no change was observed in the contralateral sides in either group (P>0.05).
CONCLUSIONSUnilateral chewing increases the oxidative metabolic ability in bilateral masseter muscle fibers especially in the non-working side accompanied with change of muscle fiber types. The improvement of aerobic metabolism ability is related to the AMPK signal pathway. .