LakeMountD
Doctor Science
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I found this QUITE interesting!!! This would mean that people using hGH probably should invest in some glutamine, especially considering how much it helps in post-exercise growth.
Growth hormone decreases muscle glutamine production and stimulates protein synthesis in hypercatabolic patients
Gianni Biolo1, Fulvio Iscra2, Alessandra Bosutti1, Gabriele Toigo1, Beniamino Ciocchi1, Onelio Geatti3, Antonino Gullo2, and Gianfranco Guarnieri1
1 Istituto di Clinica Medica, 2 Istituto di Anestesia, Rianimazione e Terapia Antalgica, and 3 Servizio di Medicina Nucleare, University of Trieste, Trieste 34149, Italy
We determined the effects of 24-h recombinant human growth hormone (rhGH) infusion into a femoral artery on leg muscle protein kinetics, amino acid transport, and glutamine metabolism in eight adult hypercatabolic trauma patients. Metabolic pathways were assessed by leg arteriovenous catheterization and muscle biopsies with the use of stable amino acid isotopes. Muscle mRNA levels of selected enzymes were determined by competitive PCR. rhGH infusion significantly accelerated the inward transport rates of phenylalanine and leucine and protein synthesis, whereas the muscle protein degradation rate and cathepsin B and UbB polyubiquitin mRNA levels were not significantly modified by rhGH. rhGH infusion decreased the rate of glutamine de novo synthesis and glutamine precursor availability, total branched-chain amino acid catabolism, and nonprotein glutamate utilization. Thus net glutamine release from muscle into circulation significantly decreased after rhGH administration (~50%), whereas glutamine synthetase mRNA levels increased after rhGH infusion, possibly to compensate for reduced glutamine precursor availability. We conclude that, after trauma, the anticatabolic action of rhGH is associated with a potentially harmful decrease in muscle glutamine production.
Growth hormone decreases muscle glutamine production and stimulates protein synthesis in hypercatabolic patients
Gianni Biolo1, Fulvio Iscra2, Alessandra Bosutti1, Gabriele Toigo1, Beniamino Ciocchi1, Onelio Geatti3, Antonino Gullo2, and Gianfranco Guarnieri1
1 Istituto di Clinica Medica, 2 Istituto di Anestesia, Rianimazione e Terapia Antalgica, and 3 Servizio di Medicina Nucleare, University of Trieste, Trieste 34149, Italy
We determined the effects of 24-h recombinant human growth hormone (rhGH) infusion into a femoral artery on leg muscle protein kinetics, amino acid transport, and glutamine metabolism in eight adult hypercatabolic trauma patients. Metabolic pathways were assessed by leg arteriovenous catheterization and muscle biopsies with the use of stable amino acid isotopes. Muscle mRNA levels of selected enzymes were determined by competitive PCR. rhGH infusion significantly accelerated the inward transport rates of phenylalanine and leucine and protein synthesis, whereas the muscle protein degradation rate and cathepsin B and UbB polyubiquitin mRNA levels were not significantly modified by rhGH. rhGH infusion decreased the rate of glutamine de novo synthesis and glutamine precursor availability, total branched-chain amino acid catabolism, and nonprotein glutamate utilization. Thus net glutamine release from muscle into circulation significantly decreased after rhGH administration (~50%), whereas glutamine synthetase mRNA levels increased after rhGH infusion, possibly to compensate for reduced glutamine precursor availability. We conclude that, after trauma, the anticatabolic action of rhGH is associated with a potentially harmful decrease in muscle glutamine production.
