1: Alcohol Clin Exp Res 1997 Aug;21(5):792-8 Related Articles, Books, LinkOut
Studies on the time-course of ethanol's acute effects on skeletal muscle protein synthesis: comparison with acute changes in proteolytic activity.
Reilly ME, Mantle D, Richardson PJ, Salisbury J, Jones J, Peters TJ, Preedy VR.
Department of Clinical Biochemistry, King's College School of Medicine and Dentistry, London, United Kingdom.
A study of the effects of ethanol on skeletal muscle protein synthesis and protease activities was carried out in young male Wistar rats (150 g) for up to 24 hr after a single intraperitoneal dose of 75 mmol of ethanol/kg of body weight. At 20 min, the mean blood ethanol levels were 448 mg/dl. This level dropped steadily to zero through the following 24 hr.
So, this study basically looks at the effects of ethanol 24 hours
after drinking it.
Compared with pair-fed controls, significant reductions in total protein, RNA, and DNA contents were seen only after 24 hr in all skeletal muscles studied: changes were more marked in the muscles containing large proportions of type II fibers. In plantaris muscle, the fractional rate of protein synthesis (ks, %/day) did not fall 20 min after dosage but was reduced after 1 hr by 23% (p < 0.001), and by 63% after 24 hr, compared with control saline-injected rats (p < 0.001).
So, let us see.......23% reduction in protein synthesis after
1 hr and 63%!!!! after 24 hours.
This effect was independent of dietary intake because,
VERY IMPORTANT: Effect was independent of dietary intake.
SO, even with a PERFECT diet, ethanol still wreaks HAVOC
with your bodies anabolicity.
compared with the pair-fed group, the 24-hr ethanol-treated rats still showed a 52% decrease in fractional rates of protein synthesis (p < 0.001). Smaller reductions in ks were seen in soleus muscles in response to ethanol at 24 hr (-39%, p < 0.001). The activities of a variety of lysosomal and nonlysosomal proteases in plantaris muscle of 24-hr treated rats were not significantly affected by ethanol. Only alanyl- and tripeptidyl-aminopeptidase activities were reduced significantly (26%, p < 0.05 and 39%, p < 0.01, respectively). These results suggest that the muscle compositional changes seen over acute periods of ethanol toxicity are predominantly associated with impaired synthesis of protein and that the contribution of cellular proteolytic systems may be minimal.
Again,
The effects of ethanol on skeletal muscle protein metabolism are greater in muscles containing a predominance of type II fibers than in those containing mainly type I fibers.
Type II fibers= LARGE muscle fibers for TRAINING.
Type I=Fast twitch for activities like walking.
Ethanol's effects on muscle may be influenced by hormonal changes after 24 hr, because protein synthesis is still compromised and free plasma T3 and corticosterone are altered at this time-point.
Even worse, ethanol causes a HORMONAL shift. It increases
estrogen through the up-regulation of the aromatase enzyme,
lowers testosterone,increases cortisol and to boot reduces
free T3 levels.
PMID: 9267527 [PubMed - indexed for MEDLINE]
Studies on the time-course of ethanol's acute effects on skeletal muscle protein synthesis: comparison with acute changes in proteolytic activity.
Reilly ME, Mantle D, Richardson PJ, Salisbury J, Jones J, Peters TJ, Preedy VR.
Department of Clinical Biochemistry, King's College School of Medicine and Dentistry, London, United Kingdom.
A study of the effects of ethanol on skeletal muscle protein synthesis and protease activities was carried out in young male Wistar rats (150 g) for up to 24 hr after a single intraperitoneal dose of 75 mmol of ethanol/kg of body weight. At 20 min, the mean blood ethanol levels were 448 mg/dl. This level dropped steadily to zero through the following 24 hr.
So, this study basically looks at the effects of ethanol 24 hours
after drinking it.
Compared with pair-fed controls, significant reductions in total protein, RNA, and DNA contents were seen only after 24 hr in all skeletal muscles studied: changes were more marked in the muscles containing large proportions of type II fibers. In plantaris muscle, the fractional rate of protein synthesis (ks, %/day) did not fall 20 min after dosage but was reduced after 1 hr by 23% (p < 0.001), and by 63% after 24 hr, compared with control saline-injected rats (p < 0.001).
So, let us see.......23% reduction in protein synthesis after
1 hr and 63%!!!! after 24 hours.
This effect was independent of dietary intake because,
VERY IMPORTANT: Effect was independent of dietary intake.
SO, even with a PERFECT diet, ethanol still wreaks HAVOC
with your bodies anabolicity.
compared with the pair-fed group, the 24-hr ethanol-treated rats still showed a 52% decrease in fractional rates of protein synthesis (p < 0.001). Smaller reductions in ks were seen in soleus muscles in response to ethanol at 24 hr (-39%, p < 0.001). The activities of a variety of lysosomal and nonlysosomal proteases in plantaris muscle of 24-hr treated rats were not significantly affected by ethanol. Only alanyl- and tripeptidyl-aminopeptidase activities were reduced significantly (26%, p < 0.05 and 39%, p < 0.01, respectively). These results suggest that the muscle compositional changes seen over acute periods of ethanol toxicity are predominantly associated with impaired synthesis of protein and that the contribution of cellular proteolytic systems may be minimal.
Again,
The effects of ethanol on skeletal muscle protein metabolism are greater in muscles containing a predominance of type II fibers than in those containing mainly type I fibers.
Type II fibers= LARGE muscle fibers for TRAINING.
Type I=Fast twitch for activities like walking.
Ethanol's effects on muscle may be influenced by hormonal changes after 24 hr, because protein synthesis is still compromised and free plasma T3 and corticosterone are altered at this time-point.
Even worse, ethanol causes a HORMONAL shift. It increases
estrogen through the up-regulation of the aromatase enzyme,
lowers testosterone,increases cortisol and to boot reduces
free T3 levels.
PMID: 9267527 [PubMed - indexed for MEDLINE]
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