Taurine is an abundant amino acid in many animals, including humans. Relatively large amounts of taurine are found in leukocytes, heart, muscles, retinas, kidneys, bones, and liver. Taurine has antioxidant effects; it reacts with hydrogen peroxide to prevent oxidation of the cell membrane. Taurine enhances the effects of anticancer drugs, while also reducing side effects, and taurolidine, a taurine derivative, has been shown to exhibit anti-cancer effects without notable side effects in several types of cancer. Taurine aids in cholesterol metabolism by increasing the rate of synthesis of bile acids, and, thus, reduces triglyceride levels. In addition, taurine is involved in the growth and differentiation of nerve cells and is associated with some neurological disorders. Taurine aids in bone formation and prevents bone dissolution. Moreover, taurine prevents liver damage from a variety of drugs and, thus, protects the liver. Taurine is involved in the development and function of the retina and lens. It also has anti-atherosclerotic and anti-thrombotic effects that protect against cardiovascular disease. Taurine may have additional physiological functions, and warrants further investigation.

Taurine is one of the most abundant free β-amino acids in the human body that accounts for 0.1% of the human body weight. It has a sulfonic acid group in place of the more common carboxylic acid group. Mollusks and meat are the major dietary source of taurine, and mother`s milks also include high levels of this amino acid. The leukocytes, heart, muscle, retina, kidney, bone, and brain contain more taurine than other organs. Furthermore, taurine can be synthesized in the brain and liver from cysteine. There are no side effects of excessive taurine intake in humans; however, in case of taurine deficiency, retinal abnormalities, reduced plasma taurine concentration, and other abnormalities may occur. Taurine enters the cell via a cell membrane receptor. It is excreted in the urine (approximately 95%) and feces (approximately 5%). Taurine has a number of features and functions, including conjugation with bile acid, reduction of blood cholesterol and triglyceride levels, promotion of neuron cell differentiation and growth, antioxidant effects, maintenance of cell membrane stability, retinal development, energy generation, depressant effects, regulation of calcium level, muscle contraction and relaxation, bone formation, anti-inflammatory effects, anti-cancer and anti-atherogenic effects, and osmotic pressure control. However, the properties, functions, and effects of taurine require further studies in future.

This study was designed to determine whether low-density lipoproteins (LDL) from egg yolk and taurine, hypotaurine and trehalose as antioxidant in extender improve the freezability and fertility of Korean Jeju Black Bull semen. The semen was cryopreserved with tris egg yolk extenders containing 7% glycerol and treated 4% LDL, 20 mM taurine, hypotaurine and trehalose. Frozen-thawed sperm were evaluated motility, viability, membrane, and acrosome integrity and sperm penetration ability. The results were compared to semen cryopreserved in tris egg yolk extender only as control. Frozen-thawed semen evaluation cleary indicated that the addition of LDL and LDL-antioxidants (taurine, hypotaurine and trehalose) combination were significantly improved (p<0.05) the viability (%; with staining test using eosin-Y) compared to control spermatozoa. Also, in membrane integrity (%; with supravital hypo-osmotic swelling test), not only LDL-antioxiants combination but also LDL were significantly increased (p<0.05) the swelled sperm using HOST compared to control. Sperm acrosome integrity state was classified by CTC (chlortetracycline) staining test. F pattern was significantly increased in LDL-antioxidant combination than control (p<0.05) and B pattern was not significantly differences among all treatments and control. However, AR pattern was significantly decreased in LDL-antioxidants combination than control (p<0.05). Pronucleus formation and sperm penetration index (SFI) were significantly increased in LDL and LDL-antioxidants combination than control (p<0.05). Especially, LDL-taurine significantly improved pronucleus fomation and SFI than LDL (p<0.05). It was concluded that LDL and LDL-antioxidants in extender improved the freezability and fertility of Korean Jeju Black bull spermatozoa.

본 연구는 돼지 정자 동결시 taurine과 ａ-tocopherol의 첨가가 융해후 정자 성상과 정자 기능 활성산소계(reactive oxygen species; ROS)의 발생 정도 및 지질 산화(lipid peroxidation, LPO)에 미치는 영향을 구명하기 위하여 시행하였다. 1차 및 2차 희석액내 taurine과 ａ-tocopherol이 첨가된 돼지 동결정액의 융해 후 정자 운동성 양상, 정자 생존성, 정자 기법을 적용하여 다음과 같은 결과를 얻었다. Taurine(25mM, 50mM), ａ-tocopherol(500㎛, 1,000㎛) 단일처리군 그리고 taurine과 ａ-tocopherol의 혼합처리군(25mM~500㎛, 50mM~1,000㎛)은 동결ㆍ융해 후 대조군과 비해 정자 운동성과 생존성은 유의적인 차이를 나타내지 않았다. Taurine과 ａ-tocopherol의 혼합처리군 50mM~1,000㎛에서 HOST, 점체 반응이 대조군과 비교하여 유의차는 인정되지 않았으나 다소 증가하였다. 동결ㆍ융해 정자의 ROS 발생 억제를 위한 taurine과 ａ-tocopherol의 모든 처리군은 대조군과 비교하여ㆍO₂- 발생을 유의적으로 완화시키지 못하였다. 그러나 taurine 단일처리군(25mM), ａ-tocopherol 단일처리군(50mM,1,000㎛)과 혼합처리군(25mM~50mM,50mM~1,000㎛)은 H₂O₂의 발생을 대조군과 비교하여 유의적으로 완화시켰다(P<0.05). 동결ㆍ융해 정자의 malondialdehyde의 생산은 taurine과 ａ-tocopherol의 모든 처리군에서 대조군과 비교하여 유의적인 감소를 보였다(P<0.05). 이상의 결과를 종합해 보면 돼지 정액의 동결보존시 taurine와 ａ-tocopherol 같은 항산화제의 처리는 ROS 발생과 LPO을 효과적으로 완화시킴에 따라 돼지 정액의 동결보존 효율을 증진시킬 수 있는 유용한 방법이라 사료된다.

Oxidative stress is one of the major causes of failure in in vitro storage of boar semen. Reactive oxygen species (ROS) are known to be important mediators of such stress. The present study examined the effects of pyruvate and taurine on sperm motility and expression of BAD, Cytochrome c, Caspase-3 and Cox-2 protein in in vitro storage of boar semen, and tested the effect of semen treated with antioxidant with or without hydrogen peroxide on the development of IVM/IVF porcine embryos. Semen samples were transported to the laboratory at 17℃ within 2 hr after collection and were treated with different concentration of pyruvate (1~10mM) and taurine (25~100mM) with or without 250uM H2O2 respectively. The supplementation of pyruvate and taurine increased sperm motility in boar semen during in vitro incubation at 37℃. Expression of apoptosis protein (BAD, cytochrome c, caspase-3 and cox-2) were reduced in the group of boar semen treated with pyruvate and taurine when compared to the other groups. The developmental rates of IVM/IVF porcine embryos fertilized by semen treated with pyruvate and taurine were significantly increased when compared to control (P<0.005). These results indicate that supplementation of pyruvate and taurine as antioxidants in boar semen extender can improve the semen quality and increase in vitro development of porcine IVM/IVF embryos when boar semen treated with antioxidants was used for in vitro fertilization.

Sodium N-acyl N-methyl taurates were synthesized by effectual acylation of fatty acid ethyl esters C(C12~C18) and N-methyl taurine. All the surface activities including krafft point, solubility, interface tension, foaming power, lime-soap dispersing ability and detergency were measured, and cmc was evaluated in dilute aqueous solution.

Essential and non-essential amino acids supplemented to culture medium stimulate mammalian embryo development in vitro. Amino acids such as glycine, taurine and alanine are concentrated in the lumen of oviduct and uterus and it can he thought that these amino acids may have physiological role on fertilization and embryo development. Our aim of this experiment was to investigate the effects of essential and non-essential amino acids, taurine or glycine supplemented to fertilization medium on the cleavage and subsequent in vitro development of bovine oocytes matured and fertilized in vitro. Immature oocytes were obtained from slaughtered Holstein cows and heifers and matured in TCM199 containing 10% fetal calf serum, 2.5 g /mL of FSH and LH and 1 g / mL of estradiol with granulosa cells in vitro. After maturation, oocytes were coincubated with sperm in fertilization medium supplemented with Minimum Essential Medium (MEM) essential and non-essential amino acids, taurine (3.75 mM) or glycine (10 mM) for 30 hours in vitro. Inseminated oocytes were cultured in synthetic oviduct fluid medium (SOEM) containing MEM essential, non-essential amino acids and 1 mM glutarnine up to 8 days after fertilization.Supplementation of fertilization medium with MEM essential and non-essential amino acids lowered significantly (p<0.05 and p<0.001) the cleavage rate after 30 hours of IVF (53.3%) and at Day 3 (62.7%: Day 0: the day of I VF) compared to control (64.3% and 77.3%, respectively). Subsequent developmental rates to morulae (Mo) and expanding blastocysts (ExBL) also significantly decreased (p<0.001 and p<0.05 for Mo and ExBL) when oocytes were coincubated with sperm in the medium containing MEM amino acids. Taurine added to fertilization medium have not increased the cleavage rate over the control, whereas glycine showed significantly lower (p<0.01) cleavage rate at Day 3 than that of taurine, but there was no significant difference in the developmental rates to Mo and ExBL of bovine embryos irrespective of the supplementation of taurine or glycine to fertilization medium. In conclusion, supplementation of fertilization medium with essential and non-essential amino acids, taurine or glycine has no beneficial effect on in vitro cleavage and development of bovine oocytes matured and fertilization in vitro.