Negative N balance can go on for 2 3 months after a serious burn injury o

Negative n balance can go on for 2 3 months after a

This preview shows page 18 - 20 out of 70 pages.

Negative N balance can go on for 2-3 months after a serious burn injury o Feeding intravenously doesn't seem to help. AAs just get oxidized. It seems like this metabolic response to stress will continue despite seemingly adequate provision of protein and NRG. The more protein you give, the more its oxidized until this phase normally passes - Also seen in other animal models where injury the amount of N secreted. It may be a generalized response, thought to have evolutionary survival value. o When you’re injured you don't need SM so you raid those tissue s and syn proteins that are better needed for survival 29. FACTORS THAT INFLUENCE Q VALUES - Differences among various investigators in their findings of Q (seemingly under similar characteristics of the individual subjects) is attributed to various factors: a) Differences in habitual physical activity There are adult populations that are more active than others b) Dietary habits Previous protein intake in years before the 2-3 day study?
Image of page 18
SFLORES_3/10/2014 19 Have to allow for acclimation to a new dietary regimen before you achieve some kind of stead state in turnover c) Differences in health status make it difficult to compare the study population with another in which their health status may be unknown d) Large inter-subject variation in Q e) Hormonal changes especially as we age, in women and men (especially testosterone). With aging comes a in testosterone secretion and this is related to changes in Q When elderly are given T in doses high enough to blood level to that of young adult men you see an in muscle protein S but you don't see a sustained in lean body mass o If T given over 2-4 wks, in protein S, but as soon as you take that T away, they lose all gained lean body mass o T supplementation can also lead to an in cancer 30. LEU SUPPLEMENTATION - A lot of work done in humans and animals of supplying excess Leu. Why is that? Leu thought to regulate protein synthesis more than any other AA o Providing bolus amounts of Leu may protein syn under various conditions [J Nutr 140:1970 2010] gave excess Leu and looked at its effect on muscle anabolic signaling in both young men and women Subsequent articles in the elderly showed that it boosts protein synthesis for short periods of time but catabolism will also eventually catch up ( catabolic rate voids protein S, so you end up with a net rate of 0) In general: “long term Leu supplementation, esp in older humans, leads to generally no net benefit. Yes, it S but down the line it C, and eventually you end up with net of 0.” 31. PROTEIN TURNOVER IN ELDERLY - With age comes a generalized loss of body protein. Every decade, whole body Q ~4-5% after adulthood. o This could be due to 2 things: 1. Decreased protein mass of the body or 2. Q expressed per unit of protein mass of the body may be different Reason depends on how much protein fed at the time Q is measured (young or old) o The young and elderly respond differently to a protein meal in terms of measuring Q
Image of page 19
Image of page 20

You've reached the end of your free preview.

Want to read all 70 pages?

  • Spring '14
  • Knutson,MitchellD
  • NRG

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors