Creatine uptake and creatine transporter expression among  rat skeletal muscle fiber types

Brault, Jeffrey J.; Terjung, Ronald L.

doi:10.1152/ajpcell.00484.2002

Cited by 31 publications

(34 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Conversely, total ␤-GPA loss differs among the fiber types with the lowest fractional rate (9% per day) found in the white gastrocnemius compared with the soleus (14% per day) and red gastrocnemius (16% per day). If the loss of ␤-GPA from the cell is representative of Cr loss, our work implies that the cellular conditions that influence degradation of Cr are different among the fiber types, a conclusion made recently from Cr uptake results (7).…”

Section: Discussionsupporting

confidence: 52%

“…9, this was observed in the slow-twitch red soleus and fast-twitch red gastrocnemius when [Cr] i was decreased below "normal" by ␤-GPA feeding. Cr uptake was measured during conditions of high extracellular Cr concentration ([Cr] e ) of 1 mM, which is well above the apparent K m for the Cr uptake into skeletal muscle (7,14,43 mal. This was not the case.…”

Section: Discussionmentioning

confidence: 99%

“…Timed samples were initially collected to verify the effective removal of perfusate radioactivity as described recently (7). The left lower hindlimb muscle sections were quick frozen at 66 min by using aluminum tongs cooled in liquid nitrogen.…”

Section: Hindquarter Perfusionmentioning

confidence: 99%

“…Differences in CrT protein expression (7,27) and activity (7) have been observed among skeletal muscle fiber types of the rat. CrT protein expression has been shown to be downregulated in skeletal muscle of some myopathies (37) and in cardiac muscle during heart failure (29).…”

mentioning

confidence: 99%

See 3 more Smart Citations

Muscle creatine uptake and creatine transporter expression in response to creatine supplementation and depletion

Brault

Abraham

Terjung

2003

Journal of Applied Physiology

Self Cite

View full text Add to dashboard Cite

The total creatine pool size [Crtotal; creatine (Cr) + phosphocreatine (PCr)] is crucial for optimal energy utilization in skeletal muscle, especially at the onset of exercise and during intense contractions. The Crtotal likely is controlled by long-term modulation of Cr uptake via the sodium-dependent Cr transporter (CrT). To test this hypothesis, adult male Sprague-Dawley rats were fed 1% Cr, their muscle Crtotal was reduced by ∼85% [1% β-guanidinoproprionic acid (β-GPA)], or their muscle Crtotal was repleted (1% Cr after β-GPA depletion). Cr uptake was assessed by skeletal muscle 14C-Cr accumulation to Cr and PCr by using hindlimb perfusion, and CrT protein content was assessed by Western blot. Cr uptake rate decreased with dietary Cr supplementation in the white gastrocnemius (WG; 45%) only. Depletion of muscle Crtotal to ∼15% of normal increased Cr uptake in the soleus (21%) and red gastrocnemius (22%), corresponding to 70–150% increases in muscle CrT content. In contrast, the inherently lower Cr uptake rate in the WG was unchanged with depletion of muscle Crtotal even though CrT band density was increased by 230%. Thus there was no direct relationship between apparent muscle CrT abundance and Cr uptake rates. However, Cr uptake rates scaled inversely with decreases in muscle Crtotal in the high-oxidative muscle types but not in the WG. This implies that factors controlling Cr uptake are different among fiber types. These observations may help explain the influence of initial muscle Crtotal, time dependency, and variations in muscle Crtotal accumulation during Cr supplementation.

show abstract

Section: Discussionsupporting

confidence: 52%

Section: Discussionmentioning

confidence: 99%

Section: Hindquarter Perfusionmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Muscle creatine uptake and creatine transporter expression in response to creatine supplementation and depletion

Brault

Abraham

Terjung

2003

Journal of Applied Physiology

Self Cite

View full text Add to dashboard Cite

show abstract

“…The rate of transport into the cell by the predominant creatine transporter SLC6A8 is around 160 mmol/kg for each muscle cell, allowing degradation and other factors to play a role [3,7,39,40]. In the typically acidic small intestine, 99% of the esterified form of creatine will be degraded back to creatine and thus have no increased effect in reaching the muscle cells [4].…”

Section: Discussionmentioning

confidence: 99%

The effect of an alkaline buffered creatine (Kre-Alkalyn®), on cell membrane behavior, protein synthesis, and cisplatin-mediated cellular toxicity

2015

Integr Mol Med

View full text Add to dashboard Cite

Endogenous creatine is created in a stable, slightly alkaline, environment. It is reasonably efficacious in delivering ATP to its target in the body. Manufactured creatine is introduced orally into an acidic environment. A percentage is degraded in the stomach, or as a result of acidophilic bacterial exposure. In either case, a certain amount of orally ingested creatine never becomes available for ATP transport. Creatine supplementation, in and of itself, has been shown to influence endothelial permeability and cell surface reactivity to a modest degree, potentially interfering/blocking an inflammatory stimulus. In vitro endothelial cell adhesion experiments demonstrate that, as creatine concentrations increase, endothelial cell surface adhesion and permeability were both modified.Creatine does not cross the plasma membrane very well. Roughly 95% of creatine is released in close proximity to the muscle tissue and transported into the cell via a limited capacity creatine-transporter system. Recent reports have shown that an artificially created alkaline environment can influence cell membrane permeability and cell behavior. The alkalinity of soda has shown anti-proliferative effects on tumor cell lines. The ability of alkaline buffered creatine to produce micro-environmental remodeling, influence cell membrane behavior and impact cisplatin-mediated toxicity, are also examined in this paper.

show abstract

Distribution of the creatine transporter throughout the human brain reveals a spectrum of creatine transporter immunoreactivity

Lowe

Faull

Christie

et al. 2014

J of Comparative Neurology

View full text Add to dashboard Cite

Creatine is a molecule that supports energy metabolism in cells. It is carried across the plasma membrane by the creatine transporter. There has been recent interest in creatine for its neuroprotective effects in neurodegenerative diseases and its potential as a therapeutic agent. This study represents the first systematic investigation of the distribution of the creatine transporter in the human brain. We have used immunohistochemical techniques to map out its location and the intensity of staining. The transporter was found to be strongly expressed, especially in the large projection neurons of the brain and spinal cord. These include the pyramidal neurons in the cerebral cortex, Purkinje cells in the cerebellar cortex, and motor neurons of the somatic motor and visceromotor cranial nerve nuclei and the ventral horn of the spinal cord. Many other neurons in the brain also had some degree of creatine transporter immunoreactivity. By contrast, the medium spiny neurons of the striatum and the catecholaminergic neurons of the substantia nigra and locus coeruleus, which are implicated in neurodegenerative diseases, showed a very low to almost absent level of immunoreactivity for the transporter. We propose that the distribution may reflect the energy consumption by different cell types and that the extent of creatine transporter expression is proportional to the cell's energy requirements. Furthermore, the distribution indicates that supplemented creatine would be widely taken up by brain cells, although possibly less by those cells that degenerate in Huntington's and Parkinson's diseases.

show abstract

Creatine uptake and creatine transporter expression among rat skeletal muscle fiber types

Abstract: Brault, Jeffrey J., and Ronald L. Terjung. Creatine uptake and creatine transporter expression among rat skeletal muscle fiber types.

Cited by 31 publications

References 55 publications

Muscle creatine uptake and creatine transporter expression in response to creatine supplementation and depletion

Muscle creatine uptake and creatine transporter expression in response to creatine supplementation and depletion

The effect of an alkaline buffered creatine (Kre-Alkalyn®), on cell membrane behavior, protein synthesis, and cisplatin-mediated cellular toxicity

Distribution of the creatine transporter throughout the human brain reveals a spectrum of creatine transporter immunoreactivity

Contact Info

Product

Resources

About