Taurine and Creatine

Miller, J. W Kleven, D. T., Domin, B. A., and Fremau Jr., R. T. (1997) Cloned sodium-land chloride-) dependent high affinity transporters for GABA, glycine, proline, betaine, taurine, and creatine, in Neurotransmitter Transporters Structure, Function, and Regulation (Reith, M. E. A., ed.). Humana Press, Totowa, NJ, pp. 101-150. 

The DAT, NET, and SERT are members of the family of Na+, Cl -dependent substrate-specific neuronal membrane transporters, which includes transporters for GABA, glycine, taurine, proline, betaine, and creatine (4-8). The putative structure of these transporters consists of 12 transmembrane domains with both the N- and C-terminal domains located within the cytoplasm. The mechanism of the transporter-mediated uptake of monoamines is believed to involve an electrogenic transport of monoamines by sequential binding and cotransport of Na+ and Cl-ions (4-8). 

Changes of both plasma and urine creatine have been reported in various models of hepatotoxicity and may be related to perturbations of cysteine and glutathione metabolism. However, the creatine changes also may be due to nutritional effects of hepatotoxins (Clayton et al. 2003, 2004). Neither taurine nor creatine measurements using high-performance liquid chromatography with tlu-orimetric or proton nuclear magnetic resonance (NMR) spectroscopy have been widely evaluated. 

In water-suppressed muscle spectra, contributions of lipids, methyl and methylene groups of creatine (Crs, Cr2), trimethylammonium-containing compounds (TMA), including signals from carnitine (Ct), choline (Cho), and taurine (Tau) are well observable as demonstrated in Fig. 15. Furthermore, small signals of histidine protons of carnosine (Cs) can be sometimes identified... 

Fig. 15. Comparison of a water suppressed muscle spectrum and a spectrum from yellow bone marrow containing almost pure fat (triglycerides). Measurement parameters STEAM sequence, TE=10 ms, TM=15 ms, TR = 2 s, 40 acq., VOI (11 X 11 X 20) mm. (a) Spectrum from TA muscle recorded after careful positioning of the VOI, avoiding inclusion of macroscopic fatty septa allows separation of extramyocellular (EMCL, broken lines) and intramyocellular lipid signals (IMCL, dotted lines) based on susceptibility differences. For this reason characteristic signals from fatty acids occur double. Signals of creatine (methyl, Crs, and methylene, Cr2) show triplet and doublet structure, respectively, due to dipolar coupling effects. Further signals of TMA (including carnitine and choline compartments), Taurine (Tau), esters, unsaturated fatty acids (-HC=CH-), and residual water are indicated, (b) Spectrum from yellow fatty bone marrow of the tibia with identical measuring parameters, but different amplitude scale.

Fig. 4. 500 MHz DOSY spectrum of a D2O solution of a perchloric acid extract of gerbil brain. Assignments of selected signals are indicated as follows ac = acetate ala = alanine cho = choline cr = creatine ere = creatinine etn = ethanolamine GABA = 7-aminobutyric acid glu = glutamate GPC = glycerophosphocholine lac = lactate m-ino = myo-inositol NAA = N-acetylaspartate succ = succinate and tau = taurine. (Raw data...

In addition to the established vitamins, a number of organic compounds have clear metabolic functions they can be synthesized in the body, but it is possible that under some circumstances (as in premature infants and patients maintained on long-term total parenteral nutrition) endogenous synthesis may not be adequate to meet requirements. These compounds include biopterin (Section 10.4), carnitine (Section 14.1), choline (Section 14.2), creatine (Section 14.3), inositol (Section 14.4), molybdopterin (Section 10.5), taurine (Section 14.5), and ubiquinone (Section 14.6). 

Fig. 1). These monoamine transporters belong to the SLC6 gene family of Na -Cl"-coupled neurotransmitter transporters that is also referred to as the neurotransmitter sodium symporter (NSS) family (Chen et al., 2004). In addition to the monoamine transporters, the NSS family includes subfamilies of transporters for GABA, amino acids, creatine, and the osmolytes betaine and taurine (Chen et al., 2004). 

Table 6.9 Input data for normal glandular prostate spectral parameters and metabolite concentrations based on in vitro data from Ref. [54]. Acronyms as previously are ppm for parts per million, au arbitrary units, denotes metabolite assignment, Q denotes concentration of Abbreviations Lac denotes lactate, Ala alanine, Cit citrate, Cr creatine, PA polyamines, Cho choline, PCho phosphocholine, GPC glycerophosphocholine, s-ins scylloinositol, Tau taurine, m-ins myoinositol.

The more complex sulphur requirements of the marine animals are met largely by cysteine, cystine, methionine, biotin, and thiamine (Young and Maw, 1958) (Fig. 4). Cysteine is a component of the tripeptide glutathione and a precursor of taurine. Methionine is as an essential amino acid involved in biosynthesis of proteins, creatine and adrenaline. Adenosylmethionine is considered to be the active part in transmethylation, e.g. of choline. Methionine is part of the pathways to homocysteine, cystathionine and methylthioadenosine (Young and Maw, 1958). Various organisms convert cysteine and/or cystine into mercapturic acids, cysteine sulphinic acid, and thiazolidine derivatives (Zobell, 1963). 

In addition to proteins, the other nitrogen compounds present in meat are free amino acids. The level of the individual amino acids is about 0.005% (their total amount is 0.1-0.3%) alanine (about 0.01%), glutamic acid (about 0.05%) and taurine (0.02-0.1%) occur in somewhat higher concentrations, followed by histidine dipeptides and guanidine compounds such as creatine and creatinine. Important groups of nitrogenous compounds are purine and... 

The primary chemical compounds involved in cell swelhng and cell volume maintenance include L-glutamine, " creatine, taurine, glycine, alanine, betaine and inositol, 22 and glucose. ... 

---