| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Metabolism Unit, Shriners Burns Institute and Departments of Surgery and Anesthesiology, The University of Texas Medical Branch, Galveston, Texas 77550
We have measured
skin and muscle protein kinetics and amino acid (AA) transport in
anesthetized rabbits during 1) 64-h
fast, 2) AA infusion,
3) AA plus fat emulsion infusion,
and 4) AA plus hyperinsulinemia.
L-[ring-13C6]phenylalanine
was infused as the tracer, and the ear and hindlimb were used as
arteriovenous units to reflect skin and muscle protein kinetics,
respectively. Skin protein net balance was not different from zero in
all groups, indicating a maintenance of protein mass. In contrast, the
muscle net balance differed over a range from 
1.6 ± 0.6 after fasting to 0.2 ± 0.2 µmol · 100 g
1 · h1
during hyperinsulinemia. In the skin, 59-66% of intracellular free phenylalanine came from proteolysis, and phenylalanine
availability from proteolysis was positively correlated to the protein
synthesis rate. In conclusion, normal skin maintains its constant
protein mass by efficient reutilization of AAs from proteolysis. In
contrast to muscle, skin protein is relatively insensitive to control
by nutritional and hormonal factors. Because of the metabolic
differences, when limb models are used for muscle protein metabolism,
the potential contribution by limb skin should be considered.
stable isotopes; mass spectrometry; arteriovenous balance; rabbits
This article has been cited by other articles:
|
|
 |
|
  X.-j. Zhang, O. Irtun, D. L. Chinkes, and R. R. Wolfe Acute responses of muscle protein metabolism to reduced blood flow reflect metabolic priorities for homeostasis Am J Physiol Endocrinol Metab, March 1, 2008; 294(3): E551 - E557. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X.-J. Zhang, D. L. Chinkes, and R. R. Wolfe Measurement of protein metabolism in epidermis and dermis Am J Physiol Endocrinol Metab, June 1, 2003; 284(6): E1191 - E1201. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X.-J. Zhang, D. L. Chinkes, and R. R. Wolfe Measurement of muscle protein fractional synthesis and breakdown rates from a pulse tracer injection Am J Physiol Endocrinol Metab, October 1, 2002; 283(4): E753 - E764. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X.-J. Zhang, D. L. Chinkes, O. Irtun, and R. R. Wolfe Anabolic action of insulin on skin wound protein is augmented by exogenous amino acids Am J Physiol Endocrinol Metab, June 1, 2002; 282(6): E1308 - E1315. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X.-J. Zhang, O. Irtun, Y. Zheng, and R. R. Wolfe Methysergide reduces nonnutritive blood flow in normal and scalded skin Am J Physiol Endocrinol Metab, March 1, 2000; 278(3): E452 - E461. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X.-J. Zhang, D. L. Chinkes, S. E. Wolf, and R. R. Wolfe Insulin but not growth hormone stimulates protein anabolism in skin wound and muscle Am J Physiol Endocrinol Metab, April 1, 1999; 276(4): E712 - E720. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
