For this reason, people with chronic kidney disease usually follow a low-protein diet to alleviate stress on the kidneys. The kidneys help regulate the body’s acid-base balance. Some amino acids are acidic, while others are basic, but dietary protein exerts an overall acidic effect.
Studies on the toxicity and antagonism of amino acids for weanling rats . The effects of excess amino acids on maintenance of pregnancy and fetal growth in rats . Effect on chick growth of amino acid imbalances in diets containing low and adequate levels of niacin and pyridoxine . The amino acid requirements of man.
While the role of BMAA in these diseases is still debated, one of the suggested mechanisms involves the activation of excitatory glutamate receptors. In particular, the excitatory effects of BMAA are shown to be dependent on the presence of bicarbonate ions, which in turn forms carbamate adducts in physiological conditions. The formation of carbamate adducts from BMAA and bicarbonate is similar to the formation of carbamate adducts from non-proteinogenic amino acids.
It is feasible to hypothesize a modulation by taurine of the skeletal muscle isoform of voltage-gated sodium channel (Nav1.4), involved in the generation and propagation of action potential and main target of symptomatic anti-myotonic drugs [37, 40]. The effect of taurine on sodium channels of native muscle fibers has been investigated in our laboratories by cell-attached patch clamp recordings. Taurine has a dual effect.
However, at present this suggestion is not supported by any significant research. In fact, opposing research indicates that the leakage of taurine from damaged cells in cardiac failure may be responsible for the elevated serum taurine levels.
Related treatment guides
This suggests that taurine supplemented muscle can store a greater quantity of calcium with a consequent greater calcium availability for contraction. However, the involvement of sarco/endoplasmic reticulum calcium-ATPase (SERCA) remains to be better clarified.
Each of these deletions, including the largest one (Î”32-134), retains 9 aa immediately following the signal peptide cleavage site (residues 23-31; KKRPKPGGW). These residues have been implicated in several biological functions of PrP, including endocytic trafficking and binding of glycosaminoglycans.
This breakdown naturally occurs when one part — the amino group — is needed to make new amino acids. Another part of the amino acid can be converted into glucose and used for energy. HMB is a metabolite of the amino acid leucine (Van Koverin and Nissen 1992), an essential amino acid.
In biochemical studies, rats given 5% tryptophan in diet for 6 wk showed increases in serotonin and 5-hydroxyindole acetic acid in the lower brain stem (107). Moreover, behavioral effects that are mediated through serotonergic neurons, e.g., reduced sleep latency, reduced food intake, depressed motor activity, and improved maze-test performance were observed in animal studies (108). Despite these reported effects in animals, no evidence exists of serious adverse effects attributable directly to tryptophan in humans, and some potentially beneficial effects, e.g., sleep enhancement (109), have been reported, so tryptophan is widely sold as a sleep aid.
vs. protein toxicity
However, taurine had little effect on muscle atrophy, which is a severe condition occurring during HU as well as in various muscle diseases . Indeed, it did not prevent the reduction of muscle-to-body weight ratio and of the fiber cross sectional area (CSA), while it partially contrasted the expression of atrogin-1 and mostly of muscle RING-finger protein-1 (MURF-1), two ubiquitin-proteasome pathway enzymes, that are strongly up-regulated as a result of HU-induced atrophy . Such an effect suggests that a longer treatment or a different therapeutic schedule of taurine might have protective effect against muscle atrophy and might be useful to reach a complete muscular recovery. However complex mechanisms control the relative expression of atrogin and MURF-1 in skeletal muscle under various insults [79, 128] and further experiments are needed (Table 1).