L-Arginine

L-Arginine and Miscarriage

Supplemental arginine during first trimester increases litter size by 30% in rats

Rats were fed a diet supplemented with 1.3% L-arginine-HCl or 2.2% control throughout pregnancy (Experiment 1), or between day 1 and 7 of gestation (gestation is usually 22 days in the rat)(Experiment 2), Litter size increased in response to arginine supplementation throughout pregnancy (14.5 vs. 11.3) or during the first 7 days of pregnancy (14.7 vs. 11.3 ). These results indicate that dietary arginine supplementation enhances embryonic survival, therefore increasing litter size by 30% at term birth. This novel finding has important implications for preventing early pregnancy loss and enhancing reproductive performance in mammals.

http://jn.nutrition.org/cgi/content/full/138/8/1421

Supplemental arginine from day 22 to end of gestation increases litter size and birth weight in pigs

Suboptimal embryonic/fetal survival and growth remains a significant problem in mammals. Using a swine model, we tested the hypothesis that dietary L-arginine supplementation (1.0% of diet) between days 22 and 114 of gestation (pig gestation is 114 days) may improve pregnancy outcomes through enhancing placental growth and modulating hormonal secretions. On days 40, 70 and 90 of gestation, concentrations of estradiol in plasma were higher in arginine-supplemented than in control sows. Compared with the control, arginine supplementation increased the total number of piglets by 1.31 per litter, the number of live-born piglets by 1.10 per litter, the litter birth weight for all piglets by 1.36 kg, and the litter birth weight for live-born piglets by 1.70 kg. Furthermore, arginine supplementation enhanced placental weight by 16.2%. The weaning-to-estrus interval of sows was not affected by arginine supplementation during gestation. These results indicate that dietary arginine supplementation beneficially enhances placental growth and the reproductive performance of sows.

http://www.ncbi.nlm.nih.gov/pubmed/21691753

Supplemental arginine from day 1 to 25 of gestation reduces litter size by 24% in pigs

Reproductive performance [numbers of corpora lutea and fetuses, placental and fetal weights, and embryonic mortality] did not differ between the 0.4% arginine and control groups. However, supplementation with 0.8% L-arginine decreased uterine weight (-20%), total number of fetuses (-24%), corpora lutea number (-17%), total fetal weight (-34%), total volume of allantoic and amniotic fluids (-34 to 42%), concentrations of progesterone in maternal plasma (-33%), as well as total amounts of progesterone (-35%), estrone (-40%), and estrone sulfate (-37%) in allantoic fluid, compared with the control group. These results indicate that dietary supplementation with 0.8% L-arginine between d 0 and 25 of gestation (gestation in pigs is 114 days), while increasing placental vascularity, adversely affects the reproductive performance of gilts.

http://jn.nutrition.org/cgi/content/full/140/6/1111

16 grams l-arginine during follicular phase improves outcome in assisted reproduction

Patients undergoing assisted reproduction were randomly assigned to two different stimulation protocols: (1) flare-up GnRHa protocol and elevated pFSH; (2) flare-up GnRHa protocol, elevated pFSH and 16 grams daily oral l-arginine. Only administered until at least one follicle >17 mm in diameter was present. In the l-arginine group the cancellation rate (11%) was lower than in group I (76%). No significant side-effects were reported by patients of l-arginine treated group. The number of oocytes collected and the number of embryos transferred were significantly higher in the l-arginine group (4.1 vs 1.6 and 2.4 vs 1, respectively). Three pregnancies (17%) were obtained in the l-arginine supplemented group, even though all of them resulted in early pregnancy loss. No pregnancies were obtained in group 1 patients.

http://humrep.oxfordjournals.org/content/14/7/1690/T2.expansion.html

Arginine does not treat vascular growth restriction

In the first double-bind, multicenter, randomized trial in this condition, L-arginine is not an effective treatment for severe vascular growth restriction.

http://www.ncbi.nlm.nih.gov/pubmed/19359073

L-arginine plus antioxidants lowers incidence of preeclampsia by 17% in high risk patients

Pregnant women with a history of a previous pregnancy complicated by pre-eclampsia, or pre-eclampsia in a first degree relative, and deemed to be at increased risk of recurrence of the disease were studied from week 14-32 of gestation and followed until delivery. The incidence of pre-eclampsia was reduced significantly in women randomized to L-arginine plus antioxidant vitamins compared with placebo (absolute risk reduction 0.17). Antioxidant vitamins alone showed an observed benefit, but this effect was not statistically significant compared with placebo. L-arginine plus antioxidant vitamins compared with antioxidant vitamins alone resulted in a significant effect (absolute risk reduction 0.09). CONCLUSIONS: Supplementation during pregnancy with a medical food containing L-arginine and antioxidant vitamins reduced the incidence of pre-eclampsia in a population at high risk of the condition.

http://www.ncbi.nlm.nih.gov/pubmed/21596735

Arginine increases the percentage of live births by 59% in sheep carrying multiple fetuses

The arginine treatment reduced the percentage of lambs born dead by 23% while increasing the percentage of lambs born alive by 59%. The i.v. administration of arginine enhanced the birth weights of quadruplets by 23% without affecting maternal body weight. The improved pregnancy outcome was associated with an increase in maternal plasma concentrations of arginine, ornithine, cysteine, and proline, as well as a decrease in circulating levels of ammonia and β-hydroxybutyrate. These novel results indicate that parenteral administration of arginine to prolific ewes ameliorated fetal mortality and growth retardation. Our findings provide support for experiments to assess the clinical use of arginine to enhance fetal growth and survival in women gestating multiple fetuses.

http://www.ncbi.nlm.nih.gov/pubmed/21430253

6 grams l-arginine improved thin endometrium in 67% of patients

To examine whether thin endometria can be improved by increasing uterine radial artery blood flow. PATIENT(S):Sixty-one patients with a thin endometrium (endometrial thickness <8 mm) and high radial artery-resistance index of uRA (>or=0.81). INTERVENTION(S): Vitamin E (600 mg/day) or l-arginine (6 g/day) was given. RESULT(S):Vitamin E improved radial artery-resistance index in 72% of patients and endometrial thickness in 52% of patients. L-arginine improved radial artery-resistance index in 89% of patients and endometrial thickness in 67% of patients. In the control group, who received no medication to increase uRA-blood flow, only one (10%) patient improved in uterine radial artery blood flow and endometrial thickness. CONCLUSION(S): Vitamin E or l-arginine treatment improves uterine radial artery blood flow and endometrial thickness and may be useful for the patients with a thin endometrium.

http://www.ncbi.nlm.nih.gov/pubmed/19200982

500 mg arginine improves sperm counts, motility, and pregnancy rates

Oral administration of 500 mg arginine-HCl per day to infertile men for 6-8 weeks markedly increased sperm counts and motility in a majority of patients, and resulted in successful pregnancies. Similar effects on oligospermia and conception rates have been reported in other preliminary trials. However, when baseline sperm counts were less than 10 million/mL, arginine supplementation produced

little or no improvement.

http://www.altmedrev.com/publications/7/6/512.pdf

Dietary arginine is required for maximum neonatal growth and embryonic survival.

http://www.ncbi.nlm.nih.gov/pubmed/22043449

L-Arginine and ADMA

ADMA interferes with the utilization of arginine, higher in PCOS women

Asymmetric dimethylarginine (ADMA) interferes with L-arginine in the production of nitric oxide. PCOS subjects had significantly elevated ADMA, MDA and hs-CRP levels relative to normals.

http://jcem.endojournals.org/cgi/content/full/93/1/82

N-acetylcysteine + L-arginine lowers insulin resistance by 39% and restores ovulation in PCOS

Eight patients with PCOS displaying oligo-amenorrhea from at least 1 yr underwent a combined treatment with N-acetylcysteine (1200 mg/day) plus L-arginine (1600 mg/day) for 6 months. Menstrual function, glucose and insulin levels, and, in turn, homeostasis model assessment index of insulin resistance were monitored. Menstrual function was at some extent restored as indicated by the number of uterine bleedings under treatment (3.00 vs 0.00). Also, a well-defined biphasic pattern in the basal body temperature suggested ovulatory cycles. Insulin resistance decreased under treatment (2.12 vs 3.48). In conclusion, this preliminary, open study suggests that prolonged treatment with N-acetylcysteine+L-arginine might restore gonadal function in PCOS. This effect seems associated to an improvement in insulin sensitivity.

http://www.ncbi.nlm.nih.gov/pubmed/19494711

Improving insulin resistance lowers ADMA levels

ADMA concentrations in non-obese, non-hypertensive and young women with PCOS are significantly higher than healthy controls and they improved by a 3-month course of metformin and oral contraceptive treatments.

http://www.ncbi.nlm.nih.gov/pubmed/18281049

Treatment with metformin ameliorated hyperandrogenemia and decreased ADMA levels.

http://jcem.endojournals.org/cgi/content/abstract/93/1/82

Arginine supplementation lowers ADMA levels

L-arginine supplementation decreased hypertension (HT), proteinuria, and ADMA levels.

http://www.ncbi.nlm.nih.gov/pubmed/18521818

Antioxidants lower ADMA levels

Catechin, vitamins E and C supplementation may moderate oxidative stress of renal failure, prevent ADMA accumulation, and counteract insulin resistance and atherosclerotic changes in the elderly.

http://www.aggjournal.com/article/S0167-4943(07)00092-1/abstract

Arginine Information

L-arginine is necessary for the production of nitric oxide, a key chemical involved in normal endothelial function (endothelial cells line the reproductive tract).

http://en.wikipedia.org/wiki/Asymmetric_dimethylarginine

Arginine is a conditionally nonessential amino acid, meaning most of the time it can be manufactured by the human body, and does not need to be obtained directly through the diet. The biosynthetic pathway however does not produce sufficient arginine, and some must still be consumed through diet. Arginine is found in a wide variety of foods.

http://en.wikipedia.org/wiki/Arginine