Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Dexamethasone inhibits small intestinal growth via increased protein catabolism in neonatal pigs

Dexamethasone inhibits small intestinal growth via increased protein catabolism in neonatal pigs Abstract Our objective was to determine how dexamethasone (Dex) affects gastrointestinal protein metabolism and growth in neonatal pigs. Two-day-old pigs were given daily subcutaneous injections of either Dex (1 mg/kg body wt, n = 7) or saline (control, n = 6) for 7 days. In vivo protein synthesis was measured after 7 days with a bolus of 3 Hphenylalanine. Tissue protein contents were measured in an initial control group of 2-day-old pigs and in control and Dex pigs after 7 days to estimate protein accretion and degradation. In control pigs, the protein accretion in the ileum was nearly sixfold greater than in the jejunum during the 7-day period. Dex nominally altered stomach growth but completely blocked the accretion of protein and DNA in the jejunum and ileum, with reduced villus height in the ileum. Dex increased the fractional protein degradation rate in the ileum (28%) and decreased the absolute protein synthesis rate in the jejunum and ileum by 17 and 21%, respectively. Dex resulted in a 40% lower total intestinal lactase activity compared with controls via reductions in both specific activity and tissue mass, especially in the ileum. Dex significantly decreased the circulating concentrations of insulin-like growth factor (IGF) I and IGF-binding protein (IGFBP)-1, -2, and -3. However, the tissue abundance of the IGF-I receptor in the stomach and ileum was greater in Dex pigs than controls. Our results suggest that Dex significantly inhibits small intestinal growth via both increased degradation and decreased synthesis of protein. Furthermore, the inhibition of intestinal growth resulted in significantly decreased lactose digestive capacity. protein synthesis glucocorticoids insulin-like growth factor I insulin-like growth factor-binding proteins lactase Footnotes Address for reprint requests: D. G. Burrin, Children’s Nutrition Research Center, 1100 Bates St., Houston, TX 77030. This work was supported in part by federal funds from the US Dept. of Agriculture (USDA)-Agricultural Research Service under Cooperative Agreement 58-6250-1-003. The contents of this publication do not necessarily reflect the views or policies of the USDA nor does mention of trade names, commercial products, or organizations imply endorsement from the US Government. Present address for T. J. Wester: Dept. of Agriculture, Univ. of Aberdeen, MacRobert Bldg., 581 King St., Aberdeen AB24 5UA, UK. The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “ advertisement ” in accordance with 18 U.S.C. §1734 solely to indicate this fact. Copyright © 1999 the American Physiological Society http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png AJP - Endocrinology and Metabolism The American Physiological Society

Dexamethasone inhibits small intestinal growth via increased protein catabolism in neonatal pigs

Loading next page...
 
/lp/the-american-physiological-society/dexamethasone-inhibits-small-intestinal-growth-via-increased-protein-oZbLWOYDAP

References

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
The American Physiological Society
Copyright
Copyright © 2011 the American Physiological Society
ISSN
0193-1849
eISSN
1522-1555
Publisher site
See Article on Publisher Site

Abstract

Abstract Our objective was to determine how dexamethasone (Dex) affects gastrointestinal protein metabolism and growth in neonatal pigs. Two-day-old pigs were given daily subcutaneous injections of either Dex (1 mg/kg body wt, n = 7) or saline (control, n = 6) for 7 days. In vivo protein synthesis was measured after 7 days with a bolus of 3 Hphenylalanine. Tissue protein contents were measured in an initial control group of 2-day-old pigs and in control and Dex pigs after 7 days to estimate protein accretion and degradation. In control pigs, the protein accretion in the ileum was nearly sixfold greater than in the jejunum during the 7-day period. Dex nominally altered stomach growth but completely blocked the accretion of protein and DNA in the jejunum and ileum, with reduced villus height in the ileum. Dex increased the fractional protein degradation rate in the ileum (28%) and decreased the absolute protein synthesis rate in the jejunum and ileum by 17 and 21%, respectively. Dex resulted in a 40% lower total intestinal lactase activity compared with controls via reductions in both specific activity and tissue mass, especially in the ileum. Dex significantly decreased the circulating concentrations of insulin-like growth factor (IGF) I and IGF-binding protein (IGFBP)-1, -2, and -3. However, the tissue abundance of the IGF-I receptor in the stomach and ileum was greater in Dex pigs than controls. Our results suggest that Dex significantly inhibits small intestinal growth via both increased degradation and decreased synthesis of protein. Furthermore, the inhibition of intestinal growth resulted in significantly decreased lactose digestive capacity. protein synthesis glucocorticoids insulin-like growth factor I insulin-like growth factor-binding proteins lactase Footnotes Address for reprint requests: D. G. Burrin, Children’s Nutrition Research Center, 1100 Bates St., Houston, TX 77030. This work was supported in part by federal funds from the US Dept. of Agriculture (USDA)-Agricultural Research Service under Cooperative Agreement 58-6250-1-003. The contents of this publication do not necessarily reflect the views or policies of the USDA nor does mention of trade names, commercial products, or organizations imply endorsement from the US Government. Present address for T. J. Wester: Dept. of Agriculture, Univ. of Aberdeen, MacRobert Bldg., 581 King St., Aberdeen AB24 5UA, UK. The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “ advertisement ” in accordance with 18 U.S.C. §1734 solely to indicate this fact. Copyright © 1999 the American Physiological Society

Journal

AJP - Endocrinology and MetabolismThe American Physiological Society

Published: Feb 1, 1999

There are no references for this article.