The amino acid taurine is a real testosterone booster, Chinese animal scientists from the Shenyang Agricultural University write in Amino Acids. The researchers gave rats taurine mixed with their drinking water, which doubled their testosterone concentrations.
The researchers were actually doing fundamental research on the role of the enzyme cysteine sulfinate decarboxylase in the testes. This enzyme converts taurine into the amino acid cysteine. So does this enzyme work in the testes as well, and if so: is that important? Do the testes need taurine to function? This is what the researchers wanted to know.
The researchers started by giving taurine to two-month-old rats. They mixed the amino acid in the animals’ drinking water in concentrations of 0.5, 1.0 and 1.5 percent. After 5 weeks the researchers noticed that the drinking water that consisted of 1 percent taurine raised the concentration of LH, FSH and testosterone in the blood. Strangely, the concentration of estradiol remained constant.
1 = FSH (mIU/ml), 2 = LH (IU/L), 3 = testosterone (ng/dl), 4 = estradiol (pg/ml).
The researchers repeated their experiment, but using hormone producing cells from the rats’ testes in test tubes. This way they found out that taurine stimulated the production of testosterone best when in a concentration of 10 microgram/ml. Higher concentrations had the reverse effect.
The researchers repeated the experiments, but after deactivating the gene for cysteine sulfinate decarboxylase with siRNA. Without taurine, the production of testosterone went down . When they added taurine to the cells, the testosterone production normalised .
So taurine is an important factor in the production of testosterone in the testes. What exactly taurine does the study does not go into. The researchers suspect that taurine increases the number of receptors for LH and FSH on hormone producing cells.
If you convert the optimal taurine dose to humans, and assume that humans have a slower metabolism than rats, then you arrive at daily intake of 5-6 g for a man weighing 85 kg.
5-6 g is quite a lot. In human studies most researchers don’t go further than 3 g taurine per day. That dose is enough to increase the concentration of taurine in the blood by several tens of percent. Fortunately, a dose of 0.6 g may boost testosterone as well.
CSD mRNA expression in rat testis and the effect of taurine on testosterone secretion.
In the present study, the cysteine sulfinate decarboxylase (CSD) mRNA expression was detected in rat testis by RT-PCR. The results showed that CSD mRNA was expressed in rat testis, and the putative encoded-amino acid sequence was exactly the same as that in rat liver which was already known. At the same time, the effects of taurine on testosterone secretion were investigated both in vivo and in vitro. In vivo, taurine were administered to male rats by tap water. The results showed that taurine obviously stimulated the secretion of FSH, LH and testosterone in serum, but showed no significant effect on the secretion of estradiol. Taurine administered in water could significantly increase the concentration of taurine in the blood and testis of rats. In vitro, cultured Leydig cells were treated with taurine independently or incubated with human chorionic gonadotropin (HCG) and progesterone. The results showed that taurine had biphasic effects on basal testosterone secretion in cultured Leydig cells. Low concentrations of taurine (0.1-100 microg/ml) could stimulate testosterone secretion, whereas high concentration of taurine (400 microg/ml) could inhibit testosterone secretion. Testosterone secretion stimulated by HCG was significantly increased by 10 and 100 microg/ml of taurine administration, and obviously decreased by treating with 400 microg/ml of taurine. Testosterone secretion induced by progesterone was significantly stimulated by treating with 1.0 and 10 microg/ml of taurine, however, it was significantly inhibited when treated with 400 microg/ml of taurine. Meanwhile, the effect of silencing CSD mRNA by siRNA on testosterone secretion was analyzed. The results showed that testosterone secretion was obviously decreased after the inhibition of CSD mRNA expression in cultured Leydig cells. These results indicated that taurine can be synthesized in rat testis by CSD pathway, and it plays important roles in testosterone secretion both in vivo and in vitro which need to be further investigated.
PMID: 19921479 [PubMed – indexed for MEDLINE]