Taurine is a versatile amino acid that contains a sulfur group rather than a carboxyl group. Don't let the chemistry jargon scare you; as you'll soon read, taurine is a multifaceted amino. Like glutamine, it can be described as a jack-of-all-trades.
Q: What does taurine do?
A: Scientists identified a role for taurine in nutrition only about 23 years ago. Taurine is involved in insulinlike activity as well as detoxification, protection of cell membranes regulation of blood pressure and the maintenance of structural proteins in muscle.
Some scientists also consider taurine a conditionally essential amino acid. Although we normally can make a certain amount of taurine, a deficiency can manifest itself in functional impairment of certain tissues; taurine may act as a growth modulator. Nevertheless, the role of taurine in human nutrition isn't completely understood. But with its multiple functions, it comes as no surprise that perhaps this amino can benefit bodybuilders.
Q: Can taurine have an anabolic effect?
A: Certainly, from a bodybuilding standpoint, nothing is more important than maintaining an anabolic state. Bodybuilders eat 5-6 times per day and maintain a high protein and carbohydrate intake while attempting to limit fat intake. They train intensely and recover sufficiently in the hope of increasing muscle protein. And of course, they take more supplements than any other athlete. Glutamine, creatine, branched-chain aminos... you name it, they consume it. Well, what about taurine? Can it play a role in the bodybuilder's arsenal of supplements?
More than 50 years ago, scientists discovered that taurine had an effect similar to that of insulin on carbohydrate metabolism it acted as a strong hypoglycemic agent. In 1964, this amino was found to increase glucose utilization in the diaphragm muscles of rats. You may be asking, Why is this important to me?" Think about it: What hormone produces a drop in blood-glucose levels and transports glucose into cells? Insulin! Now, you may not agree with this, but some scientists refer to insulin as "the anabolic hormone." Indeed, insulin promotes the influx of amino acids and glucose into muscle tissue. The importance of insulin should be self-evident.
Taurine mimics the action of insulin both in vivo (in living organisms) and in vitro (test tubes). In one experiment, it stimulated glucose uptake into cells at 50% the capacity of insulin. Insulin and taurine also similarly increase the uptake of the amino acid proline into rat diaphragms. Interestingly, the combination of insulin and taurine was no better than either insulin or taurine by itself. Furthermore, like insulin, taurine can stimulate the formation of glycogen in cardiac muscle, certainly an important aspect of your training.
Q: Is taurine involved in cell volumization?
A: Maintaining a given cellular volume affects the anabolic machiney of a given tissue or cell. In the liver, for example, glycogen synthesis is stimulated by amino acids and insulin via a mechanism that involves cell swelling. This may also be true in skeletal muscle.
Cellular swelling can be evoked by exposure of a cell to what scientists refer to as hypo-osmotic conditions. When a cell is in a hypo-osmotic medium, fluid tends to move into the cell, and this change in cell volume is associated with changes in both glycogen and protein synthesis.
The involvement of taurine in volume regulation has been demonstrated in the brain, cells in culture and nervous tissue. One experiment on the effect of extracellular taurine on volume regulation of cerebellar neurons (a type of brain cell) showed that as taurine levels increased to a certain level, a swelling of these cells occurred.
It isn't clear how much taurine can affect cell volume in skeletal muscle cells nor how physiologically important taurine is in regulating muscle protein synthesis. Therefore, don't expect too much from taurine in terms of muscle volumization.
Q: What effect does taurine have on skeletal muscle?
A: We know that a high concentration of taurine exists in skeletal muscles. Since most taurine in skeletal muscle is present as a free amino acid, a physiological role probably exists. Taurine has been shown to participate in the excitation-contraction coupling mechanism in skeletal muscle, which means that it affects the transmission of an electrical signal into muscle fibers. This has obvious importance in ensuring optimal muscle performance.
Taurine has also been shown to prevent the decrease in structural proteins present in skeletal muscle. In one rodent study, researchers examined the gastrocnemius, soleus and extensor digitorum longus (EDL) muscles after denervating (cutting off the nerve supply) these muscles for up to 28 days. Interestingly, the amount of taurine increased in certain denervated muscles. For instance, in the EDL, a predominantly fast-twitch muscle, denervation caused a near doubling of taurine concentration. In the gastrocnemius, a mixed fast/slow-twitch muscle, taurine increased, but much less than in the EDL. In the soleus, a predominantly slow muscle, taurine concentration didn't change.
So a fiber type or muscle-specific response appears to exist with regard to taurine; fast fibers are seemingly affected more than slow fibers. The physiological importance of this isn't entirely clear, but keep in mind that in human muscle, fast-twitch fibers seem to show the greatest growth in response to resistance training. So it isn't unreasonable to expect taurine to aid in muscle-fiber growth when coupled with intense training.
Q: Does taurine have an effect on the cardiovascular system?
A: Since taurine is a multifaceted amino acid, you shouldn't be too surprised to learn that it affects blood pressure. Researchers used rats bred to have high blood pressure to study the effects of differing concentrations of taurine on food intake, bodyweight and blood pressure. Taurine was administered in the animals' drinking water either as a 1% or 3% solution over a period lasting eight weeks.
The amino had no effect on body-weight and food intake, but blood pressure decreased by the fourth week of treatment and remained lower than the untreated group throughout the treatment period. The 3% taurine solution had a greater effect on blood pressure than the 1% solution. Taurine-treatcd animals had significantly higher tissue levels in kidney and skeletal muscle, yet levels in certain parts of the brain didn't change.
The physiological significance of the increased taurine levels in these tissues is uncertain. While these findings may not be particularly exciting for bodybuilders, they are important for general health.
Q: How would you summarize taurine's effects?
A: Taurine can he considered a conditionally essential amino acid, similar to glutamine. It has numerous effects, some of which could help bodybuilders. For example, it has an insulinlike effect with regard to glucose and amino-acid metabolism. In addition, it may play a role in fast-twitch muscle growth. These effects have obvious implications for bodybuilders. Taurine may also be involved in the regulation of the volume in some cells as well as blood pressure.
Taurine can be made from the amino acids methionine and cysteine; however, because certain stresses (free radical and oxidant cell damage) may decrease levels of taurine, you may need to take taurine as a regular part of a daily supplementation program.
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