View clinical trials related to Protein Metabolism.
Filter by:Several of the investigator's recent studies have shown that all dietary proteins are not equal when it comes to making proteins in human bodies. Generally, foods made from animal muscle tissue are much more efficient at making new proteins in the body that those from plant sources. This study will measure the amount of protein growth in participants after consuming either one beef patty, one vegi-burger, or two vegi-burgers. By using stable isotope infusions and collecting blood and leg muscle samples, the investigator's lab can determine the rate of muscle metabolism that happens after a participant eats a protein-containing food. The investigator wants to determine if the vegi-burger is as efficient as the beef patty at creating proteins in a participants. The investigator will measure this metabolism over a 10-hour period, with the food being eaten at the 4 hour mark. The investigator plans to perform this procedure on up to 8 participants per food option (24 total).
Dietary protein is digested in the stomach and intestines to smaller peptides and 20 individual amino acids which, when absorbed by the gut into circulation and taken up by skeletal muscle, help stimulate muscle protein synthesis (MPS). Amino acids also provide the building blocks for muscle proteins that contribute to lean mass gains and increased strength following resistance exercise. Therefore, strategies to efficiently maximize amino acid exposure without overconsumption are warranted. Oral enzyme supplementation is a candidate approach to optimize amino acid absorption from dietary protein and protein supplements. Microbial proteases, approved for dietary supplement use, can theoretically speed up the conversion of protein and peptides to amino acids. Protease supplements have been marketed to promote muscle strength by optimizing amino acid absorption, however the clinical evidence is limited. This work will support that ingestion of protease supplements with a meal can allow individuals to more efficiently increase amino acid levels from a given amount of dietary protein.
Episodes of inactivity due to hospitalisation, as short as 5 days, are associated with rapid muscle and strength loss in the elderly. The observed muscle loss with inactivity is likely due to muscle anabolic resistance and increased breakdown rates of muscle tissue. This is of great concern as the average hospital stay in the elderly is 5-6 days. Moreover, minor illnesses not requiring hospitalisation generally require short-term periods of inactive home-based recovery. The accumulation of repeated disuse events in older individuals manifests in a chronic muscle anabolic resistance (i.e. the inability of muscle to respond to anabolic stimuli such as exercise and nutrition) that may underpin the slow but devastating process of age-related muscle loss. It is our belief that strategies to promote muscle health in ageing and reduce healthcare expenditure, should focus on alleviating muscle deterioration and anabolic resistance during short-term disuse. In this regard, we propose that resistance exercise (i.e. weight lifting) performed prior to a disuse event (termed 'prehabilitation') may be sufficient to offset muscle loss in older individuals. Thus, we suggest the potent effect of resistance exercise in older muscles may prevent muscle loss during short-term disuse.
The anabolic action of 'fast' whey protein on the regulation of postprandial muscle protein synthesis has been established to be short-lived in healthy young adults. Our aim was assess the time course of anabolic signaling events and stimulation of muscle protein synthesis rates (MPS) after ingestion of a food source that represents a more typical meal-induced pattern of aminoacidemia, namely milk protein concentrate, in healthy young males.
Skeletal muscle quality is an important determinant of exercise performance and overall health. It is vital for not just movement, but also metabolizing nutrients. Protein from the diet can promote muscle protein synthesis for muscle recovery and growth. More importantly, doing so shifts net protein balance positively (e.g. protein synthesis is greater than protein breakdown) and promotes greater rates of muscle protein turnover. Leucine is an amino acid required to build muscle, but it also acts as a signaling molecule informing the muscle to start protein synthesis. Before reaching skeletal muscle, dietary protein is digested into small peptides and free amino acids. Rate of absorption from the intestine to the blood stream is significantly faster for peptides compared to amino acids. As amino acid availability in the blood is a precursor for muscle protein synthesis, our objective is to determine if the different absorption rates between free amino acid and peptides influence muscle protein synthetic and breakdown rates.
The primary aim of the trial is to determine the optimal dose of protein per meal in relation to enhancing muscle protein synthesis and thereby in perspective counteract muscle loss during weight loss. In addition, we aim to determine whether the response to protein intake is reduced in women on hypocaloric diet compared to in women on an energy-balanced diet.
The investigators will examine the effects of a given amount of a protein food source such as pork, mixed nuts, and tofu on anabolic response at the whole body and muscle levels in young, healthy adults.
A randomized interventions study using a crossover design. Ten well trained triathletes or bikeriders will be included for to undergo two trail separated by about 3 weeks. The night before the trail each subject will performe a high intense interval trainings session on an ergometer bike. during the night an infusion of aminoacid tracers will be initiated. The subject is woken at 6.30 a.m. Blood samples and a musclebiopsy will be collected prior to the morning bike ride at 8.00a.m. Immediately before the morning bike ride is started the subject will ingest a drink of 0,5g protein or a non-caloric placebo (random order). During the bike ride and the following 4,5 hours blood will be drawn with regular intervals. at time point 0, 60 and 180 min after the training session biopsies are collected.
The investigators will determine effects of different sources of protein on whole-body net protein synthesis and muscle protein synthesis in young healthy participants.
Rationale: Osteoarthritis (OA) of the knee is a common cause of pain and disability, especially in people over the age of 65. In the current health care system both conservative (e.g. intra-articular injections with corticosteroids) and surgical (total knee replacement, TKR) treatment are applied. Although frequently used, certain effects of these treatments on protein metabolism remain unclear. It is well known that maintenance of different tissues is determined by a dynamic balance between protein synthesis and breakdown rates, with temporary changes in either protein synthesis or breakdown allowing net protein accretion or loss. Though protein supplementation has shown to be an effective nutritional strategy in stimulating muscle protein synthesis, it remains unclear to what extent other musculoskeletal tissues are able to respond to dietary protein supplementation. Therefore, the current study assesses the impact of preoperative protein supplementation on protein synthesis in different musculoskeletal tissues of the knee. Objective: To investigate the effect of preoperative protein supplementation on Hoffa's fat pad, synovium, tendon, bone, muscle, ligament, menisci, and cartilage protein synthesis of the OA knee. Study design: Randomized, parallel (two groups) study design. The intervention group will be compared to the control group. Study population: 24 adults with OA of the knee undergoing TKR. Intervention: Daily 40 g of pre-sleep protein two weeks before TKR or no intervention. Main study parameters/endpoints: Primary study parameters include protein synthesis rates and enrichments of Hoffa's fat pad, synovium, tendon, bone, muscle, ligament, menisci, and cartilage. Secondary parameters include whole-body protein synthesis, breakdown, oxidation, and net balance. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The risks involved in participating in this study are minimal. There are no potential effects known for the ingestion of protein. Muscle biopsies and tissue collection will be performed during the surgical procedure.