Tuesday, March 12, 2013

Muscle Mumbo Jumbo - cAMP, mTor, Alpha-2 receptor, Beta-2 Adrenoreceptor, GLUT4


According to Wikipedia, "Cyclic adenosine monophosphate (cAMP, cyclic AMP or 3'-5'-cyclic adenosine monophosphate) is a second messenger important in many biological processes. cAMP is derived from adenosine triphosphate (ATP) and used for intracellular signal transduction in many different organisms, conveying the cAMP-dependent pathway.

cAMP and its associated kinases function in several biochemical processes, including the regulation of glycogen, sugar, and lipid metabolism."

Supplement Support:  It seems there is no direct support for this but a quick search mentions caffeine, Nicotinamide adenine dinucleotide (NADH) and Peak ATP are supplements that seem to be related. If ATP is the source, then Ribose, Magnesium, Creatine and COQ10 would also be of benefit.

Simply put mTOR pathway = protein synthesis or the process of building and repairing muscle.

Wikipedia states it as “mTOR integrates the input from upstream pathways, including insulin, growth factors (such as IGF-1 and IGF-2), and amino acids.[3] mTOR also senses cellular nutrient and energy levels and redox status.[5] The mTOR pathway is dysregulated in human diseases, especially certain cancers.[4] Rapamycin is a bacterial product that can inhibit mTOR by associating with its intracellular receptor FKBP12.[6][7] The FKBP12-rapamycin complex binds directly to the FKBP12-Rapamycin Binding (FRB) domain of mTOR.[7]
mTOR is the catalytic subunit of two molecular complexes.[8]
mTOR stands for mammalian Target Of Rapamycin and was named based on the precedent that TOR was first discovered via genetic and molecular studies of rapamycin-resistant mutants of Saccharomyces cerevisiae that identified FKBP12, Tor1, and Tor2 as the targets of rapamycin and provided robust support that the FKBP12-rapamycin complex binds to and inhibits the cellular functions of Tor1 and Tor2.”

Supplements: BCAA, Leucine, HICA and HMB, Ipriflavone (maybe)

1.        Anthony J. C., Anthony T. G., Kimball S. R., Vary T. C., Jefferson L. S. Orally administered leucine stimulates protein synthesis in skeletal muscle of postabsorptive rats in association with increased eIF4F formation. J. Nutr. 2000;130:139-145

2.        Tischler M. E., Desautels M., Goldberg A. L. Does leucine, leucyl-tRNA, or some metabolite of leucine regulate protein synthesis and degradation in skeletal and cardiac muscle?. J. Biol. Chem. 1982;257:1613-1621

3.        Kimball S. R., Shantz L. M., Horetsky R. L., Jefferson L. S. Leucine regulates translation of specific mRNAs in L6 myoblasts through mTOR-mediated changes in availability fo eIF4E and phosphorylation of ribosomal protein S6. J. Biol. Chem. 1999;274:11647-1

4.        Buse M. G., Weigand D. A. Studies concerning the specificity of the effect of leucine on the turnover of proteins in muscles of control and diabetic rats. Biochim. Biophys. Acta 1977;475:81-89

5.        Patti M. E., Brambilla E., Luzi L., Landaker E. J., Kahn C. R. Bidirectional modulation of insulin action by amino acids. J. Clin. Invest. 1998;101:1519-1529

6.        Shigemitsu K., Tsujishita Y., Miyake H., Hidayat S., Tanaka N., Hara K., Yonezawa K. Structural requirement of leucine for activation of p70 S6 kinase. FEBS Lett 1999;447:303-306

7.        Fox H. L., Pham P. T., Kimball S. R., Jefferson L. S., Lynch C. J. Amino acid effects on translational repressor 4E-BP1 are mediated primarily by L-leucine in isolated adipocytes. Am. J. Physiol. Cell Physiol. 1998b;275:C1232-C1238

8.        Furst P. New developments in glutamine delivery. J Nutr. 2001 Sep;131(9 Suppl):2562S-2568S.

9.        Klassen P, et al. The pharmacokinetic responses of humans to 20 g of alanyl-glutamine dipeptide differ with the dosing protocol but not with gastric acidity or in patients with acute Dengue fever. J Nutr. 2000 Feb;130(2):177-182

10.     Rogero MM, et al. Plasma and tissue glutamine response to acute and chronic supplementation with L-glutamine and L-alanyl-L-glutamine in rats. Nutr Res. 2004 Apr;24(4):261-270

11.     Rogero MM, et al. Effect of alanyl-glutamine supplementation on plasma and tissue glutamine concentrations in rats submitted to exhaustive exercise. Nutrition. 2006 May;22(5):564-571

12.     Shih FF. Analysis of glutamine, glutamic acid and pyroglutamic acid in protein hydrolysates by high-performance liquid chromatography. J Chromatogr. 1985 Mar 29;322(1):248-256

13.     Archibald RM. Chemical characteristics and physiological roles of glutamine. Chem Rev. 1945 Oct;37(2):161-208

14.     Stehle P, et al. Isotachophoretic analysis of synthetic dipeptide L-alanyl-L-glutamine: Evidence for stability during heat sterilization. J Chromatogr. 1984;294:507-512

15.     Khan K, et al. The stability of L-glutamine in total parenteral nutrition solutions. Clin Nutr. 1991 Aug;10(4):193-198

16.     Khan K & Elia M. Factors affecting the stability of L-glutamine in solution. Clin Nutr. 1991 Aug;10(4):186-192

Simply put, GLUT4 transports sugars into either fat storage or muscle.

Wikipedia says, "Glucose transporter type 4, also known as GLUT4, is a protein that in humans is encoded by the GLUT4 gene. GLUT4 is the insulin-regulated glucose transporter found in adipose tissues and striated muscle (skeletal and cardiac) that is responsible for insulin-regulated glucose transport into the cell. This protein is expressed primarily in muscle and fat cells, the major tissues in the body that respond to insulin. The first evidence for this distinct glucose transport protein was provided by David James in 1988.[1] The gene that encodes GLUT4 was cloned[2][3] and mapped in 1989.[4]"

[1] Based on one published clinical trial in ten healthy exercise-trained males. Nutrition and Metabolic Insights 2011:4 39–47

[2] Cheng Z, Pang T, Gu M, et al. Berberine-stimulated glucose uptake in L6 myotubes involves both AMPK and p38 MAPK. Biochim Biophys Acta. 2006 Nov;1760(11):1682-9.

Beta-2 Adrenoreceptor
According to USPLabs, "The receptor is believed to activate the same signaling pathway as anabolic hormones--without the side effects.

Wikipedia says: "This receptor is directly associated with one of its ultimate effectors, the class C L-type calcium channel CaV1.2. This receptor-channel complex is coupled to the Gs G protein, which activates adenylyl cyclase, catalysing the formation of cyclic adenosine monophosphate (cAMP) which then activates protein kinase A, and the counterbalancing phosphatase PP2A. The assembly of the signaling complex provides a mechanism that ensures specific and rapid signaling. A two-state biophysical and molecular model has been proposed to account for the pH and REDOX sensitivity of this and other GPCRs.[6]
Beta-2 Adrenergic Receptors have also been found to couple with Gi, possibly providing a mechanism by which response to ligand is highly localized within cells. In contrast, Beta-1 Adrenergic Receptors are coupled only to Gs, and stimulation of these results in a more diffuse cellular response.[7] This appears to be mediated by cAMP induced PKA phosphorylation of the receptor.[8]"
Source Citation (MLA 7th Edition)

Alpha-2 receptor 
Simply put blocking this receptor allows more fat to be burned. 
According to Wikipedia, "The α2-adrenergic receptor binds both norepinephrine released by sympathetic postganglionic fibers and epinephrine (adrenaline) released by the adrenal medulla, binding epinephrine with slightly higher affinity[citation needed]. It has several general functions in common with the α1-adrenergic receptor, but also has specific effects of its own."
Supplements: Fall into the category of antagonists. They are the stimulants Yohimbine and Rauwolscine.

1.        McCarthy CG, Farney TM, Canale RE et al. A Finished Dietary Supplement Stimulates Lipolysis and Metabolic Rate in Young Men and Women. Nutrition and Metabolic Insights 2012:5 23-31

2.        McCarthy CG, Canale RE, Alleman Jr. RJ et al. Biochemical and Anthropometric Effects of a Weight Loss Dietary Supplement in Healthy Men and Women. Nutrition and Metabolic Insights 2012:5 13-22

3.        Farney TM, McCarthy, CG, Canale RE et al. Hemodynamic and Hematologic Profile of Healthy Adults Ingesting Dietary Supplements Containing 1,3-Dimethylamylamine and Caffeine. Nutrition and Metabolic Insights 2012:5 1-12