GPLC - glicina propionil-L-carnitina

[Shade]

Ciao a tutti, qualcuno di voi ha mai sentito parlare di questo prodotto che aumenta il rilascio di NO e diminuisce l'acido l'attico post allenamento????

Ho letto un'articolo dove sono stati presi 2 gruppi circa 32 uomini e sottoposti ad allenamenti per la resistenza, assumendo 4,5gr di GPLC pre allenamento ed hanno riscontrato ( a detta loro) un aumento del 15% della potenza e una diminuzione del 16% dell'acido lattico post esercizio rispetto all'assunzione di un placebo......
Si ritiene che gli effetti siano dovuti ad un'aumento del NO nei tessuti muscolari, insieme al miglioramento dell'effetto tampone sull'acido lattico e della rigenerazione dei substrati energetici.

Cosa ne pensate??? Tutte bufale o fondo di verità????

grazie

[mistersalvo]

ottima...però nn sò se è notificata da noi...
sarebbe un pre wo semplice ed efficace...meno ac.lattico +NO +lipolisi...
meglio di cosi...

[Shade]

Perchè nn dovrebbe essere notificato?????

[greatescape]

perche prima di essere notificata una cosa deve essere controllata e si deve essere sicuri che non faccia male
come il caso del hmb

[Shade]

Sull'articolo, c'era scritto che è una sostanza molto studiata e che nn presenta "problemi" ora nn so se sia una cosa detta per commercializzare il tutto.....

[LiborioAsahi]

4.5gr? ma in che forme la si può trovare qui da noi?

[greatescape]

scusa hmb è stato approvato ora
cissus pure non è tossico ad alti dosaggi
la creatina e tante sostanze sono autorizzate a determinati dosaggi
insomma tutte cose che dovrebbero farti pensare
se una cosa non è autorizzata qui in italia non è detto subito che non lo sia perche faccia male

[Shade]

Si ok, ma io volevo sapere se e' vero quello che ho letto, se sono vere le sue proprietà ....

[greatescape]

se hai letto uno studio perche non dovrebbe essere vero
devi avere il beneficio del dubbio su prodotti brevettati dove gli studi sono fatti solo dall'azienda detentrice del brevetto
quando vedi uno studio fatto bene devi leggere come è stato condotto i dosaggi le somministrazioni ecc
allora cosi tu puoi "replicare" se vuoi
un marchio al massimo esagera nel descrivere le caratteristiche o magari usa un ingrediente che funziona ma con quantita basse

[mistersalvo]

Introducing Glycine Propionyl-L-Carnitine

Glycine propionyl-L-carnitine, or GPLC, is a molecular-bonded form of propionyl-L-carnitine and the amino acid glycine. We have demonstrated an increase in blood levels of NOx, a surrogate marker of NO, with oral GPLC intake of 4.5 grams a day.15 Our findings agree with recent work in which investigators demonstrated an increase in blood NOx in subjects who received six grams per day of propionyl-L-carnitine intravenously.16

In our first study with GPLC previously sedentary men and women were assigned to supervised aerobic exercise with GPLC treatment or a placebo for eight weeks.17 It was a double-blind design—neither subjects nor investigators were aware of who got which substance. We noted a significant increase in resting levels of blood NOx for the subjects who got GPLC compared to those who got the placebo. Those who received GPLC also had lower lipid peroxidation, a measure of free-radical-mediated oxidation of lipids. That’s important, as increased free-radical production is associated with impaired NO bioavailability. In addition, excess free-radical production may be associated with impaired contractile function, reductions in muscle force output and greater fatigue rates in isolated skeletal muscle.18

Overtraining has also been linked to decreased presence of antioxidants in the blood.19 Considering the training regimens of many bodybuilders, adequate antioxidant protection appears of great importance. That’s particularly true considering that excessive free-radical production leads to poor health and a variety of diseases.20 Therefore, antioxidant supplementation may be helpful.

You need free radicals in low amounts for important physiological functions, such as cell signaling, immune response and apoptosis, the regular disintegration of used-up cells.21 So total elimination of free radicals—assuming it was possible—wouldn’t be desirable. Rather, an appropriate balance between free-radical production and antioxidant protection is the goal. In those who require additional antioxidant protection, a dietary ingredient such as GPLC may prove helpful.

Our second double-blind study involving GPLC was with resistance-trained men who were given GPLC or a placebo for four weeks each, with a two-week washout period between phases.15 Resting blood samples were obtained at the end of each four-week phase, and blood was drawn following isometric forearm exercise. Those getting GPLC had more NOx in their blood than those who got the placebo, a finding that may have implications related to enhanced blood flow during acute bouts of exercise.

More Research Needed

While those results are interesting, we have no evidence at this time that the increase in NOx will be associated with enhanced blood flow—we did not include that measure in our designs. A soon-to-be-published study, however, indicates promising effects on exercise performance associated with GPLC supplementation. Of course, additional questions related to the impact of GPLC on muscle recovery remain to be answered. Clearly, more work needs to be done. It may be something to keep your eyes on during the coming months, as other studies are now being completed, are under way or are being planned. Stay tuned

Editor’s note: Richard J. Bloomer, Ph.D., and his team have been studying the effects of GPLC since 2005 with the support of Sigma-tau Health Science, the manufacturer of the product. They encourage readers to examine the material presented, as well as the reference data provided, at PubMed home.

References
1 Collier, J., and Vallance, P. (1991). Physiological importance of nitric oxide. BMJ. 32:1289-1290.
2 Jobgen, W.S., et al. (2006). Regulatory role for the arginine-nitric oxide pathway in metabolism of energy substrates. J Nutr Biochem. 9:571-588.
3 Anderson, J.E. (2000). A role for nitric oxide in muscle repair: Nitric oxide-mediated activation of muscle satellite cells. Mol Biol Cell. 11:1859-1874.
4 Salanova, M., et al. (2008). Molecular biomarkers monitoring human skeletal muscle fibres and microvasculature following long-term bed rest with and without countermeasures. J Anat. 212(3):306-18.
5 Bode-Boger, S.M., et al. (1994). Exercise increases systemic nitric oxide production in men. J Cardiovasc Risk. 1:173-178.
6 Clarkson, P., et al. (1999). Exercise training enhances endothelial function in young men. J Am Coll Cardiol. 33:1379-1385.
7 Gilligan, D.M., et al. (1994). Contribution of endothelium-derived nitric oxide to exercise-induced vasodilation. Circulation. 90:2853-2858.
8 Hickner, R.C., et al. (1997). Role of nitric oxide in skeletal muscle blood flow at rest and during dynamic exercise in humans. Am J Physiol. 273(1 Pt 2):H405-410.
9 Edwards, D.G., et al. (2004). Effect of exercise training on endothelial function in men with coronary artery disease. Am J Cardiol. 93(5):617-20.
10 Poveda, J.J., et al. (1997). Contribution of nitric oxide to exercise-induced changes in healthy volunteers: Effects of acute exercise and long-term physical training. Eur J Clin Invest. 27(11):967-971.
11 Tordi, N., et al. (2006). Effects of resuming endurance training on arterial stiffness and nitric oxide production during exercise in elite cyclists. Appl Physiol Nutr Metab. 31(3):244-249.
12 Adams, M.R., et al. (1995). Oral arginine inhibits platelet aggregation but does not enhance endothelium-dependent dilation in healthy young men. J Amer Col Cardiology. 26(4):1054-61.
13 Chin-Dusting, J.P., et al. (1996). Effects of in vivo and in vitro L-arginine supplementation on healthy human vessels. J Cardiovasc Pharmacol. 28(1):158-166.
14 Robinson, T.M., Sewell, D.A., and Greenhaff, P.L. (2003). L-arginine ingestion after rest and exercise: Effects on glucose disposal. Med Sci Sports Exerc. 35:1309-1315.
15 Bloomer, R.J., et al. (2007). Glycine propionyl-L-carnitine increases plasma nitrate/nitrite in resistance trained men. J Inter Soc Sports Nutr. 4:22, Epub Dec 3.
16 Loffredo, L., et al. (2007). Oxidative-stress-mediated arterial dysfunction in patients with peripheral arterial disease. Eur Heart J. 28(5):608-612.
17 Bloomer, R.J., et al. (2008). Glycine propionyl-L-carnitine modulates lipid peroxidation and nitric oxide in human subjects. Int J Vit Nutr Res. In press.
18 Reid, M.B. (2001). Nitric oxide, reactive oxygen species, and skeletal muscle contraction. Med Sci Sports Exerc. 33(3):371-376.
19 Palazzetti, S., et al. (2003). Overloaded training increases exercise-induced oxidative stress and damage. Can J Appl Physiol. 28(4):588-604.
20 Dhalla, N.S., et al. (2000). Role of oxidative stress in cardiovascular diseases. J Hypertens. 18:655-673.
21 Vollaard, N.B., et al. (2005). Exercise-induced oxidative stress: Myths, realities and physiological relevance. Sports Med. 35:1045-1062. IM

[mistersalvo]

Glycine propionyl-L-carnitine increases plasma nitrate/nitrite in resistance trained men

Department of Health and Sport Sciences, University of Memphis, Memphis, TN, USA

Abstract

We have recently demonstrated that oral intake of glycine propionyl-L-carnitine (GPLC) increases plasma nitrate/nitrite (NOx), a surrogate measure of nitric oxide production. However, these findings were observed at rest, and in previously sedentary subjects.
Purpose

In the present study, we sought to determine the impact of oral GPLC on plasma NOx at rest and in response to a period of reactive hyperemia in resistance trained men.
Methods

Using a double blind, crossover design, 15 healthy men (24 ± 4 years) were assigned to GPLC (3 g/d PLC + 1044 mg glycine) and a placebo in random order, for a four-week period, with a two-week washout between condition assignment. Blood samples were taken from subjects at rest and at 0, 3, and 10 minutes following an ischemia-reperfusion protocol (six minutes of upper arm cuff occlusion at 200 mmHg followed by rapid reperfusion with cuff removal). Blood samples were taken from a forearm vein from the same arm used for the protocol and analyzed for total nitrate/nitrite. Data are presented as mean ± SEM.
Results

A condition main effect (p = 0.0008) was noted for NOx, with higher values in subjects when using GPLC (45.6 ± 2.8 μmol·L-1) compared to placebo (34.9 ± 1.2 μmol·L-1). No time main effect was noted (p = 0.7099), although values increased approximately 12% from rest (37.7 ± 2.7 μmol·L-1) to a peak at 10 minutes post protocol (42.3 ± 3.3 μmol·L-1). The interaction effect was not significant (p = 0.8809), although paired time contrasts revealed higher values for GPLC compared to placebo at 3 (48.2 ± 6.7 vs. 34.9 ± 2.4 μmol·L-1; p = 0.033) and 10 (48.8 ± 5.9 vs. 35.7 ± 2.1 μmol·L-1; p = 0.036) minutes post protocol, with non-statistically significant differences noted at rest (41.8 ± 4.5 vs. 33.6 ± 2.5 μmol·L-1; p = 0.189) and at 0 minutes (43.6 ± 5.1 vs. 35.4 ± 2.7 μmol·L-1; p = 0.187) post protocol. An analysis by subject (collapsed across time) indicated that 11 of the 15 subjects experienced an increase in NOx with GPLC treatment.
Conclusion

These findings indicate that short-term oral GPLC supplementation can increase NOx in resistance trained men. However, as with many dietary supplements, there exist both "responders" and "non-responders" to treatment. Future work may focus on the mechanisms for the discrepancy in response to GPLC supplementation for purposes of NOx elevation.
Introduction

Nitric oxide (NO•) is an important signaling molecule, promoting vasodilation by acting on vascular smooth muscle [1]. In addition, NO• has been linked to other physiological functions such as inhibition of platelet aggregation and platelet adhesion [2]. In these ways, NO• mediates increased blood flow at rest [3-5] and during exercise [4,6,7], which may have implications for those with chronic ischemic disease as well as for athletes interested in enhancing blood flow to working skeletal muscle (e.g., endurance athletes, bodybuilders).

Nitric oxide is synthesized from L-arginine by the endothelium in the vascular system [2] and has been reported to increase in response to acute exercise [8-13]. This is true for dynamic [4], as well as for isometric [7] exercise, in which reperfusion is present following cessation of the contraction. Moreover, chronic exercise training has been reported to result in an increase in plasma nitrate/nitrite (NOx) levels [14-16], a surrogate marker of NO•.

Aside from exercise, pharmaceutical agents have been used with success to induce NO• biosynthesis, in an attempt to promote vasodilation (for review please see [17]). Treatments have sometimes included high dosages of L-arginine, often provided via intravenous injection. This has led to the development of several nutritional supplements, often containing small amounts of L-arginine, which are purported to have "drug-like" action, ultimately leading to increased NO•. While the fitness industry is inundated with advertisements for such products, the scientific data are scant. We have recently demonstrated an increase in plasma NOx in healthy sedentary subjects following oral treatment with a novel carnitine agent, glycine propionyl-L-carnitine (GPLC; [18]). This finding extends recent work of Lofreddo et al. [19] who reported an increase in blood NOx in response to 6 grams per day of PLC given via IV infusion to patients with peripheral arterial disease. Other reports suggest vasodilatation actions with PLC [20], in addition to glycine [21] treatment independently. However, our initial findings using oral GPLC were observed at rest, and in previously sedentary subjects, individuals who quite possibly have lower resting NOx levels compared to well-trained subjects; hence, may have a greater potential for responding to GPLC treatment. To our knowledge, no studies have been done to evaluate the efficacy of nutritional supplements to increase NOx levels in a sample of potential users (e.g., resistance trained athletes). Therefore, in the present study, our purpose was to determine the impact of oral GPLC on plasma NOx at rest and in response to a period of reactive hyperemia in resistance trained men. Using a double blind, randomized, crossover design, we hypothesized that plasma NOx would be higher with GPLC treatment compared to placebo, at rest and in response to the ischemia-reperfusion protocol.
Methods
Subjects

Fifteen healthy, resistance trained men participated in this investigation. Subjects completed a medical history, diet and supplementation history, and physical activity questionnaire to determine eligibility. No subject was a smoker or used anti-inflammatory drugs or antioxidant supplements before (for a minimum of six months) or during the study period. Subjects were young (24 ± 4 yrs; mean ± SD), and of average height (177 ± 5 cm), weight (83 ± 4 kg), and body fat percentage (14 ± 5 %). Subjects were considered to be well-trained and performed resistance exercise for 5 ± 2 hrs per week for 8 ± 5 yrs. They were instructed not to deviate from their current training regimen during the course of the study with the exception of refraining from exercise for the 48 hours prior to each testing day. All experimental procedures were performed in accordance with the Helsinki Declaration. The University of Memphis Human Subjects Committee approved all experimental procedures. All subjects provided both verbal and written consent prior to participating in this study.
Conditions

Subjects were randomly assigned in double-blind manner using a cross-over design to GPLC and a placebo. Each intake period consisted of four weeks, with a two-week washout period between condition assignments. Subjects were instructed to ingest a total of six capsules per day of GPLC or placebo (at two separate times – morning and evening). Based on recent evidence indicating that carnitine uptake is enhanced with carbohydrate feeding [22,23], subjects were instructed to take capsules along with a carbohydrate rich meal. GPLC is a USP grade nutritional supplement as of March 2006, consisting of a molecular bonded form of propionyl-L-carnitine (PLC) and the amino acid glycine (GlycoCarn™, Sigma-tau HealthScience S.p.A, Rome, Italy). In the total 4.5 g/d dosage of GPLC, the actual PLC content was equal to 3 g and the glycine content was equal to 1044 mg (the remainder of the capsule consisted primarily of cellulose). The short term (8–9 week) safety of GPLC supplementation at the dosage provided (4.5 g/d) was established in our initial work [18], where we noted no adverse changes in subjects' complete blood count or blood chemistry panel data. Capsules were manufactured by Jarrow Formulas (Los Angeles, CA), were identical in appearance, and were provided to subjects in unlabeled bottles every two weeks. Compliance to intake was determined based on capsule counts upon bottle return.
Results

Of the 16 subjects who started the study, only data from 15 subjects were included in the analysis. One subject failed to return to the lab for the second testing session; therefore, data for this subject were excluded. Compliance to GPLC and placebo intake was ≥ 97% for both conditions based on capsule counting upon return of bottles. Subjects indicated their compliance to our recommendation of maintenance of their specific exercise regimen during the course of the study period. The mean daily intake of kilocalories (2750 ± 195 vs. 2801 ± 217; p = 0.86), protein grams (155 ± 14 vs. 157 ± 15; p = 0.91), carbohydrate grams (330 ± 23 vs. 340 ± 34; p = 0.76), and fat grams (87 ± 9 vs. 81 ± 7; p = 0.60) during the week prior to GPLC and placebo conditions, respectively, did not differ. Analyses of diet records indicated that no subject regularly consumed nitrate- (e.g., spinach, cabbage, beets, radishes) or nitrite-rich foods during the diet reporting periods; therefore, we do not believe that dietary intake influenced the plasma NOx values.

A condition main effect (p = 0.0008) was noted for NOx, with higher values in subjects when using GPLC (45.6 ± 2.8 μmol·L-1) compared to placebo (34.9 ± 1.2 μmol·L-1). No time main effect was noted for NOx (p = 0.7099), although values increased approximately 12% from rest to a peak at 10 minutes post protocol. The interaction effect for NOx was not significant (p = 0.8809), although paired time contrasts revealed higher values for GPLC compared to placebo at 3 (p = 0.033) and 10 (p = 0.036) minutes post protocol. The interaction data for NOx are presented in Figure 1. An analysis by subject (collapsed across time) indicated that 11 of the 15 subjects experienced an increase in NOx with GPLC treatment.
Conclusion

In summary, our findings indicate that short-term oral GPLC supplementation can increase NOx in resistance trained men. However, there exist both "responders" and "non-responders" to treatment. Findings from this study may have health implications for those with ischemic conditions such as peripheral vascular disease and ischemic heart disease, as increased NOx may allow for enhanced blood flow, in particular during times of physical stress. Moreover, these findings may relate specifically to athletes who seek enhanced blood flow during periods of strenuous exercise, as such a change may be associated with improved physical performance during training and optimal post exercise recovery. Future study is needed to determine what, if any, physiologic benefit is associated with the observed increase in plasma NOx with GPLC supplementation.