Analysis of creatine, creatinine, creatine-d3 and creatinine-d3 in urine, plasma, and red blood cells by HPLC and GC–MS to follow the fate of ingested creatine-d3

MacNeil, Lauren; Hill, Lisa M.; MacDonald, Daniel J.; keefe, L; Cormier, James F.; Burke, Darren; Smith‐Palmer, Truis

doi:10.1016/j.jchromb.2005.09.011

Cited by 36 publications

(21 citation statements)

References 31 publications

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“…This data and others suggest that the in vivo regulation of creatine synthesis and degradation is highly regulated in vivo. Yet only a small fraction of ingested creatine reaches the tissues [6].…”

Section: Discussionmentioning

confidence: 99%

“…Several reports have noted that creatine degradation is a function of pH, as a result of an increased rate of intramolecular cyclization [2,4,5]. Based on GC-MS determination, under normal physiological conditions, it is estimated that 10% of ingested creatine is converted to creatinine and roughly 78% of ingested creatine is taken up in vivo [6]. Creatine has very few side effects, which makes it an ideal supplement for metabolic experimentation [7,8].…”

Section: Introductionmentioning

confidence: 99%

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

2015

Integr Mol Med

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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.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

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

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“…Several studies have demonstrated that apparent absorption of creatine after oral administration is around 80-90+ % [ 51 , 52 ]. A study with single oral dosing of deuterated creatine in one subject revealed whole body uptake of 78 % [ 53 ]. More rigorous analysis, including fecal creatine and creatinine measurements, along with periodic urine collection, has shown apparent creatine absorption to approximate 100 %, with trivial conversion of creatine into creatinine [ 49 ] (signifi cant creatine to creatinine conversion is often asserted by some creatine-centric SPN marketers [ 54 ]).…”

Section: Misdirected: Indirect and Direct Measuresmentioning

confidence: 99%

Beyond the Obvious: Future Innovations in Sports Nutrition

Almada¹

2015

Nutritional Supplements in Sports and Exercise

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The global proliferation of sports nutrition brands is emblematic of the size of consumers seeking enhancements through this class of ingestible products. However, a nearly ubiquitous theme of commonality is shared by these products: the compositions are often close to identical, differing only by amount and description, with ancillary alterations in fl avor or packaging. How many branched chain amino acid or whey protein compositions can be birthed? The future of sports nutrition will continue to witness the penetration of multinational (food, beverage, and pharma) brands entering the fray through acquisition, and patent fi lings, which may foster a generic storm or heightened innovation. What remains most compelling is the opportunity for true innovation and pioneering to disrupt the highly duplicative sports nutrition product landscape. Such adventurous excursions may include systematic research/innovation programs that provide novelty, compelling proof of concept, and "real-world" utility; implementation of research methods that provide direct, inferential insights into the bioavailability and metabolism of bioactives; and novel protein/amino nitrogen sources that mimic the biological effects of whey protein.

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“…Previous reports suggest that the degradation of creatine results from pH changes [2,8,9]. Indeed at normal physiological pH, 10% of creatine has been suggested to convert to creatinine, it's most common byproduct [10].…”

Section: Introductionmentioning

confidence: 99%