Nitric Oxide Information

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AAKG (Arginine-alpha-ketoglutarate):

Originally Posted by WillBrink

As you know, Arginine-alpha-ketoglutarate (AAKG) has been purported to increase nitric oxide synthesis and thereby enhance blood flow, oxygen delivery, and glucose uptake to muscle leadingto greater gains in strength and muscle mass during training. For this reason, nitric oxide stimulating supplements have become a popular supplement among resistance trained athletes. While there is some theoretical rationale as to the potential ergogenic value, the effects of AAKG supplementation during training has yet to be determined.
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-> 1.
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PURPOSE:
_This study examined the effects of AAKG supplementation during training on body composition and training adaptations in experienced resistance trained men (30-50 yrs).
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METHODS:
Subjects took 4 grams of the supplements three times daily (12 g/d) for 8-weeks during standardized training. At 0, 4, and 8-weeks, subjects had DEXA body composition determined and performed 1RM bench press,
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RESULTS:

No significant differences were observed between groups in changes in body mass , fat free mass, fat mass , or percent body fat.
Changes in bench press 1RM , sprint peak power , time to peak power , and rate to fatigue were significantly greater in the AAKG group while no differences were observed in average power_ or total work .
No significant differences were observed in isokinetic leg extension peak torque, maxrepetition total work, time to peak torque, total work, work fatigue, or average power during the muscular endurance test or maximal oxygen uptake.
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CONCLUSION: Results indicate that AAKG supplementation may augment 1RM strength and sprint power in response to training but does not appear to significantly effect body composition. (Sponsor: Medical Research Institute, San Francisco, CA)
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-> 2.
PURPOSE:_
This study examined the effects of AAKG supplementation during training on markers of health status in experienced resistance trained men (30-50 yrs).
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METHODS:
Subjects took 4 grams of the supplements three times daily (12 g/d) for 8-weeks during standardized training. At 0, 4, and 8-weeks, subjects donated fasting blood samples and had resting heart rate and blood pressure determined.
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RESULTS:
No significant interactions were observed between groups in resting or maximal systolic blood pressure, diastolic blood pressure, mean arterial pressure, or rate pressure product responses.
No clinically significant side effects or adverse events were reported in weekly follow-up assessments or during the maximal stress tests.
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CONCLUSION: AAKG supplementation does not appear to significantly affect markers of catabolism or adversely affect general markers of health. (Sponsor: Medical Research Institute, San Francisco, CA)
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-> 3.
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PURPOSE:
This study examined the effects of arginine alphaketoglutarate (AAKG) supplementation during training on QOL and perceptions about training, health, and libido in experienced resistance trained men (30-50 yrs).
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METHODS:
Subjects took 4 grams of the supplements three times daily (12 g/d) for 8-weeks during standardized training. At 0, 4, and 8-weeks, subjects completed the SF-36 quality of life questionnaire and a training, health, and libido questionnaire.
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RESULTS:
No significant interactions were observed between groups in the SF-36 subscales of bodily pain , general health , mental health , physical functioning , role emotional , social functioning , vitality , or role physical. Likewise, no significant differences were foundbetween groups in positive attitude toward training , ability to recover from training sessions ,body satisfaction in terms of muscularity and muscle hardness, sexual desire/libido , erectile function/quality , quality of sleep , or feeling of energy when waking up .
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CONCLUSION:
Though non-significant results are reported, a number of interesting trends were observed in response to AAKG supplementation that deserves additional study. (Sponsor: MedicalResearch Institute, San Francisco, CA)

Originally Posted by Patrick Arnold

There are many other mechanisms by which AAKG can enhance performance. It can have positive effects on cell metabollism that have nothing to do with NO

Chances are, any putative benefits seen have nothing to do with NO actually

....AAKG BTW has benefits above and beyon arginine alone and alpha-ketoglutarate alone (at least according to the literature)

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Arginine Alpha-Ketoisocaproate (AKIC):

Relative nutritional efficacy of arginine and ornithine salts of alpha- ketoisocaproic acid in traumatized rats

M Jeevanandam, MR Ali, NJ Holaday, JK Weis and SR Petersen
Trauma Center, St Joseph's Hospital and Medical Center, Phoenix, AZ 85013.

The relative dietary efficacy of arginine alpha-ketoisocaproate (AKIC) and ornithine alpha-ketoisocaproate (OKIC) is evaluated in a rat (Sprague-Dawley) trauma (bilateral femur fracture) model. Both control and traumatized rats were starved for 2 d and then pair-fed for 2 or 4 d one of three liquid diets: diet 1 was a basic casein diet; diets 2 and 3 were the basic diet in which 10% of nitrogen was replaced by AKIC or OKIC nitrogen, respectively. Irrespective of the diet, the protein- efficiency ratio, defined as the gain in body weight per grams nitrogen consumed, was 27% less in traumatized rats than in control rats. More improvement in apparent nitrogen balance, particularly in traumatized rats, was seen with the AKIC supplement. Plasma amino acid patterns demonstrated stimulation of net protein synthesis with AKIC and not with OKIC. Dietary supplementation with AKIC may be beneficial to promote nitrogen economy in trauma victims.

Alpha-ketoisocaproate is not a true substrate for ATP production by pancreatic beta-cell mitochondria

N Lembert and LA Idahl
Department of Histology and Cell Biology, Umea University, Sweden. nicolas.lembert@histocel.umu.se

The ability of alpha-ketoisocaproate (KIC) to induce ATP production in isolated mitochondria from pancreatic beta-cells was examined with a bioluminometric method. There was no ATP production from KIC when tested alone or in combination with malate (1 mmol/l), nor did DL-beta-hydroxybutyrate induce mitochondrial ATP production, whereas palmitoyl-carnitine and pyruvate were efficient stimulators of mitochondrial ATP production in the presence of an equimolar concentration of malate. However, KIC stimulated the mitochondrial ATP production when tested in combination with glutamate (10 mmol/l). The concentration necessary to obtain half-maximal stimulation was approximately 50 micromol/l KIC, and maximal activity, comparable to that obtained with fatty acids, was reached at 1 mmol/l KIC. Higher KIC concentrations inhibited the mitochondrial ATP production, whereas a plateau was attained at 1 mmol/l KIC in the presence of glutamine. Ca2+ stimulated the maximal mitochondrial ATP production induced by KIC. Maximal stimulation was obtained with 300 nmol/l Ca2+ in the presence of 0.3 mmol/l KIC. Ca2+ reduced the concentration of KIC necessary for half-maximal stimulation to <30 micromol/l. Leucine stimulated the mitochondrial ATP production in the presence of glutamate to the same extent as KIC. Half-maximal stimulation was observed with 2 mmol/l leucine. There were no additive effects on mitochondrial ATP production when KIC and leucine were tested in combination. The results demonstrate that KIC by itself is not a mitochondrial substrate for ATP production. KIC must transaminate with glutamate or glutamine to yield alpha-ketoglutarate and leucine. Since leucine allosterically activates glutamate dehydrogenase, which also produces alpha-ketoglutarate, the insulinogenic effect of KIC may in part be due to the intramitochondrial generation of alpha-ketoglutarate. Since KIC-induced ATP production reaches a plateau already at micromolar concentrations (i.e., far below the concentrations at which KIC induces insulin release), it is proposed here that the catabolism of KIC may induce additional signals related to insulin release.

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More on eNOS:

There are several forms of Nitric Oxide Synthase (NOS) including iNOS, eNOS, and nNOS ( nNOS is similar to eNOS and produced in the brain). iNOS is an unfavorable process that produces Nitric Oxide during inflammation. This form of Nitric Oxide is very harmful and iNOS is an extremely potent oxidative free radical (destroys cells). An increase in eNOS activity is responsible for lowering of blood pressure, and "opening up the blood vessels" effectively lowering bad cholesterol, and increasing the nutrient carrying capacity of the cells. This increase in diameter of blood cells also leads to what is being called a "sustained-pump." The pump you normally feel when exercising [is] a result of eNOS activity.

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THE CLINICAL PHARMACOLOGY OF L-ARGININE:

.PDF format

http://forum.bodybuilding.com/attach...6&d=1133000694


Regulation of endothelial derived nitric oxide in health and disease

.PDF format

http://forum.bodybuilding.com/attach...1&d=1135605763


Ginseng Pharmacology: A Nitric Oxide Link?

.PDF format

http://www.sciencedirect.com/science.../sdarticle.pdf

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Topical Nitric Oxide (US Patent # 6,458,841) discussion:

http://forum.bodybuilding.com/showthread.php?t=406442

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Cnidium and Nitric Oxide:

Science / Theory:



Nitric Oxide stimulates cGMP production

cGMP = cyclic guanosine monophosphate = increased blood flow / cell volumization

PDE-5 (Phosphodiesterase-V) binds to and destroys cGMP

Cnidium Monnier, the natural form of 4-methylpiperazine increases nitric oxide release, and inhibits PDE-5

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Polyamines and Arginine / Nitric Oxide / Cell Growth:

.PDF format

http://forum.bodybuilding.com/attach...0&d=1141480352

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Topical Aloe Vera: Wound healing properties.... a Nitric Oxide link?

Activation of a mouse macrophage cell line by acemannan: the major carbohydrate fraction from Aloe vera gel.
Zhang L, Tizard IR.
Department of Veterinary Pathobiology, Texas A & M University College Station 77843, USA.

Acemannan is the name given to the major carbohydrate fraction obtained from the gel of the Aloe vera leaf. It has been claimed to have several important therapeutic properties including acceleration of wound healing, immune stimulation, anticancer and antiviral effects. However, the biological mechanisms of these activities are unclear. Because of this wide diversity of effects, it is believed that they may be exerted through pluripotent effector cells such as macrophages. The effects of acemannan on the mouse macrophage cell line, RAW 264.7 cells were therefore investigated. It was found that acemannan could stimulate macrophage cytokine production, nitric oxide release, surface molecule expression, and cell morphologic changes. The production of the cytokines IL6 and TNFalpha were dependent on the dose of acemannan provided. Nitric oxide production, cell morphologic changes and surface antigen expression were increased in response to stimulation by a mixture of acemannan and IFNgamma. These results suggest that acemannan may function, at least in part, through macrophage activation.


Acemannan, a beta(1,4)acetylated mannan, induces nitric oxide production in macrophage cell line RAW 264.7
Ramamoorthy L.; Kemp M.C.; Tizard I.R.
Dept. of Veterinary Pathobiology, Texas A and M University, College Station, TX 77843 USA
Molecular Pharmacology (USA) , 1996, 50/4 (878884)

Acemannan is a polydispersed beta(1,4)linked acetylated mannan with antiviral properties. It is an immunomodulator, and studies in our laboratory have shown that it causes activation of macrophages. Inducible NO synthase is generally expressed after transcriptional induction and is known to mediate some of the cytotoxic action of activated macrophages. Acemannan, in the presence of interferongamma, greatly increased the synthesis of NO in RAW 264.7 cells. This increase was preceded by increased expression of mRNA for the inducible form of macrophage NO synthase. Preincubation with pyrrolidine dithiocarbamate inhibited the induction, indicating the involvement of nuclear factorkappaB. These results suggest that acemannan causes the activation of macrophages by increasing the level of NO synthase at the level of transcription.


Nitric oxide production by chicken macrophages activated by Acemannan, a complex carebohydrate extracted from Aloe vera
Karaca K.; Sharma J.M.; Nordgren R.
University of Minnesota, College of Veterinary Medicine, Department of Pathobiology, St Paul, MN 55108 USA
International Journal of Immunopharmacology (United Kingdom) , 1995, 17/3 (183188)

Cultures of normal chicken spleen cells and HD11 line cells produce nitric oxide (NO) in response to Acemannan, a complex carbohydrate derived from the Aloe vera plant. Neither cell type produced detectable amounts of NO in response to similar concentrations of yeast mannan, another complex carbohydrate. Nitric oxide production was dose dependent and inhibitable by the nitric oxide synthase inhibitor N(G)methylLarginine. In addition, the production of NO was inhibited by preincubation of ACM with concanavalin A in a dose dependent manner. These results suggest that ACMinduced NO synthesis may be mediated through macrophage mannose receptors, and macrophage activation may be accouantable for some of the immunomodulatory effects of ACM in chickens.

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Nobel committee says yes to 'NO'

The 1998 Nobel Prize in Physiology and Medicine

The Nobel Foundation recently announced its winner for the 1998 Nobel Prize in Physiology and Medicine. The prestigious honor goes this year to three Americans who independently made important contributions to the discovery that the gas nitric oxide (chemical formula NO) can act as a signaling molecule. Since its discovery, it has been found to play important roles in a variety physiological systems, including the nervous system where it can act as a second messenger, and as a neurotransmitter.

There is a bit of irony in the topic of the award this year. The Nobel Prize was created by Alfred Nobel who invented a process to stabilize nitroglycerine to form dynamite. Even in his day, it was known that small amounts of nitroglycerin would relieve angina heart pain through some undetermined mechanism. And, Nobel was himself treated with this compound for his heart condition. Now, about one century later, the award is being given for work that elucidated the mechanism by which nitroglycerine can relieve angina.

The discovery of NO as a signaling molecule

The work that eventually lead to the discovery of NO as a signaling molecule began with an investigation of drugs that caused relaxation or contraction of vascular smooth muscle. Initial experiments showed that acetylcholine caused a contraction of an isolated smooth muscle preparation made from aorta, the large artery that caries blood away from the heart. This was somewhat of a paradox since cholinergic drugs that act the same way as acetylcholine cause vasodilation (relaxation of the vascular smooth muscle) when given systemically.

Later experiments gave contradictory results, and further investigation led to the finding that if the epithelium associated with the vascular smooth muscle were intact, cholinergic drugs would cause relaxation of the smooth muscle, while in preparations where the epithelial cells were removed, it would cause contraction. This led to the conclusion that the epithelial cells released some chemical that caused the smooth muscle to relax and the search was on for this new compound, then called endothelium-derived relaxing factor (EDRF).

Around the same time, work was being done to determine how certain nitrogenous compounds, like nitroglycerine could affect vascular smooth muscle. This work showed that these compounds released NO, and that it was the NO that was effecting the relaxation of smooth muscle. This led to the hypothesis that EDRF could be NO, a hypothesis that was shortly confirmed. Later work found the synthetic enzyme that makes NO (nitric oxide synthase, or NOS) and its distribution throughout many tissues, including in the peripheral and central nervous systems.

NO in the brain

As a signaling molecule, NO is very unique. It is the first gas that has ever been shown to act as a signaling molecule. Furthermore, NO is a caustic component of diesel exhaust that is highly reactive (for example, white blood cells also create NO as one of the weapons they use to kill bacteria.) But NO was soon found to be involved in may physiological process, including penile erection; the drug Viagra works by exploiting a signaling pathway that uses NO.

To add to the surprise, an isoform of NOS that makes NO was found to be widely, but selectively distributed in the brain. This led to the idea that NO was acting as a neurotransmitter in the brain. Since then, scientists have learned that NO is involved in a number of neuronal functions including long-term potentiation (a cellular basis for learning), synapse formation, drug tolerance and dependence, modulation of sensory and motor pathways, local regulation of cerebral blood flow, neuroendocrine regulation, learning, and feeding and sexual behavior. I will deal more with the mechanism of NO action in the brain in a later feature article.

The Prize Recipients

Dr. Robert F. Furchgott
Ph.D. Biochemistry, Northwestern University,
Department of Pharmacology, SUNY Health Science Center

Dr. Furchgott studied the effects of various drugs on blood vessels. He found that in some cases, the same drug caused contradictory results. Work in his lab demonstrated that the different results depended on whether the epithelial lining of the blood vessels was intact and from this concluded the epithelial cells released some chemical that caused relaxation of the blood vessels. Much of his research efforts in the 1970's and 1980's were directed toward elucidating the nature of this compound, that he called endothelium-derived relaxing factor (EDRF), and that he later concluded was NO.

Dr. Louis J. Ignarro
Ph.D. Pharmacology, University of Minnesota
Department of Molecular and Medical Pharmacology, UCLA School of Medicine

Dr. Ignarro was also on the quest for the identity of ENDF. His laboratory independently, and simultaneously with Dr. Furchgott's demonstrated that ENDF was NO. Results from both labs were presented at the same scientific conference in July, 1986.

Dr. Freid Murad
M.D./Ph.D. Pharmacology, Western Reserve University
Department of Integritive Biology, Pharmacology, and Physiology, University of Texas Medical School at Huston.

Dr. Murad investigated the way that compounds like nitroglycerine cause vasodilation. In 1977, he discovered that these compounds release NO, and that this in turn was the factor that caused relaxation of the vascular smooth muscle. In 1977, he hypothesized that endogenous factors may also work through NO, and it was his work that paved the way for the research of Drs. Furchgott and Ignarro that demonstrated that endogenously released NO from epiltheial cells can effect vasodilation.

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Dietary L-Arginine Supplementation Improves the Glomerular Filtration Rate and Renal Blood Flow After 24 Hours of Unilateral Ureteral Obstruction in Rats.

Ito K, Chen J, Vaughan ED Jr, Seshan SV, Poppas DP, Felsen D.

SUMMARY: PURPOSE Unilateral ureteral obstruction (UUO) results in a significant change in renal blood flow (RBF) and glomerular filtration rate (GFR) by 24 hours. The intake of L-arginine, a substrate of nitric oxide (NO) synthase (NOS), can augment NO production. NO can maintain renal function through its vasodilatory action. Therefore, we examined the effect of dietary arginine supplementation on renal function in UUO.

MATERIALS AND METHODS GFR and RBF were measured by inulin and para-aminohippurate clearance, respectively, in control rats and in rats 24 hours after UUO. Rats were given arginine with or without the concomitant administration of N-nitro-L-arginine methyl ester. Urinary nitrate/nitrite (NO2/NO3) was measured by the Griess reaction and urinary cyclic guanosine monophosphate was determined by enzyme-linked immunosorbent assay. The expression of renal inducible NOS was determined by immunohistochemistry.

RESULTS Urinary NO2/NO3 was significantly increased after 2 weeks of arginine, confirming increased NO production. In control rats GFR and RBF were not significantly different in untreated vs arginine treated groups. In contrast, arginine treatment significantly increased GFR in the obstructed kidney (0.06 +/- 0.01 to 0.14 +/- 0.02 ml per minute per 100 gm) and the contralateral kidney compared with control UUO. RBF was also significantly increased by arginine. The increases in renal function with arginine were blunted by a NOS inhibitor in obstructed and contralateral kidneys. Inducible NOS expression was increased in obstructed and contralateral kidneys.

CONCLUSIONS This study demonstrates that L-arginine supplementation can improve renal function in acute UUO. This finding suggests that NO system may be a future site of pharmacological intervention for UUO.

FYI