Reexamination of protein requirements in adult male humans by end-product measurements of leucine and lysine metabolism

Article Abstract:

The flux and oxidation of leucine and lysine during fed and postabsorptive periods in adult male humans were determined by end-product measurements of amino acid metabolism. The results showed that leucine flux and oxidation were sensitive to meal feeding and protein intake. Similar responses to varying protein intakes were not observed with lysine. In addition, the oxidation of leucine during the postabsorptive state did not reflect the true protein intake levels. These results demonstrate that amino acid requirements should not be estimated during the postabsorptive state. A new protein requirement for adult males was estimated at 0.6-0.8 grams per kilo per day.

Health aspects, Measurement, Nutrition, Leucine, Lysine, Nutritional requirements, Amino acid metabolism

---

Metabolic responses induced by isoproterenol in ractopamine-fed pigs

Article Abstract:

The metabolic effects of isoproterenol on ractopamine-fed pigs was studied by measuring fat tissue and metabolites after intravenous administration of the drug. This resulted to enhanced production of metabolites. Blood glucose levels increased secondary to decreased tissue uptake and glycogenolysis in the muscle. Consequently, the plasma level of lactate and nonesterified fatty acids were also elevated due to lipolysis although lipogenesis in adipose tissues is decreased. The physical effects are seen as a diminished fat cell mass, increased muscle mass and the metabolic shift to the utilization of fatty acids for energy.

Research, Lipid metabolism, Adipose tissues, Adipose tissue, Isoproterenol, Sympathomimetic agents

---

Porcine skeletal muscle myofibrillar protein synthesis is stimulated by ractopamine

Article Abstract:

The effect of ractopamine on protein synthesis in muscle was evaluated in barrows given a diet containing 130 or 170 grams of protein per kilogram body weight. Results indicated that ractopamine enhanced synthesis of myofibrilar protein. Protein synthesis and breakdown in biceps femoris were likewise stimulated by ractopamine. Consequently, there was an increase in the protein composition of the longissimus dorsi and the biceps femoris.

Protein synthesis, Adrenergic beta agonists, Adrenergic beta-agonists

Similar abstracts:

• Abstracts: The determination of nutritional requirements: mathematical modeling of nutrient-response curves. Introduction to modeling
• Abstracts: Porcine colostrum and milk stimulate visceral organ and skeletal muscle protein synthesis in neonatal piglets

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.