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Dexamethasone and colostrum feeding affect hepatic gluconeogenic enzymes differently in neonatal calves.
Journal article

Dexamethasone and colostrum feeding affect hepatic gluconeogenic enzymes differently in neonatal calves.

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  • 2003-12-18
Published in:
  • Journal of animal science. - 2003
Adrenocorticotropic Hormone
Animal Nutritional Physiological Phenomena
Animals
Animals, Newborn
Blood Glucose
Blood Urea Nitrogen
Cattle
Colostrum
Dexamethasone
Diet
Food, Formulated
Gene Expression Regulation, Enzymologic
Glucagon
Glucocorticoids
Hydrocortisone
Insulin
Liver
Liver Glycogen
Male
Phosphoenolpyruvate Carboxylase
Pyruvate Carboxylase
RNA, Messenger
English Plasma glucose concentrations in neonates are influenced by colostrum feeding and by glucocorticoids. We have tested whether a high-glucocorticoid status after birth, as well as colostrum feeding, influences glucose metabolism in association with changes of hepatic expression and activities of gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK; EC 4.1.1.32) and pyruvate carboxylase (PC; EC 6.4.1.1) in neonatal calves. Calves (n = 14 per group) were fed either colostrum or a milk-based formula with nutrient and energy contents similar to colostrum. Half the calves in each feeding group were treated with dexamethasone (DEXA; 30 microg/[kg BW x d]). Pre- and postprandial blood samples were taken on d 1, 2, 4, and 5 and liver samples were collected on d 5 of life. Dexamethasone treatment increased (P < or = 0.05) plasma concentrations of glucose, insulin, and glucagon more in colostrum-fed than in formula-fed calves but increased (P < or = 0.05) urea concentrations and decreased (P < or = 0.05) concentrations of NEFA, ACTH, and cortisol independent of colostrum vs. formula feeding. Colostrum feeding increased (P < 0.05) plasma glucose, but decreased (P < 0.05) plasma urea concentrations. Glucagon-to-insulin ratios in DEXA-treated and colostrum-fed calves were decreased (P < 0.05). Dexamethasone treatment decreased hepatic mRNA levels and activities of PC (P < 0.001 and P < 0.10) and activities of PEPCK (P < 0.001) but increased (P < 0.001) the glycogen content. Colostrum feeding increased (P < 0.05) mitochondrial PEPCK mRNA levels and PEPCK activities in calves not treated with DEXA but decreased (P < 0.1) amounts of PC mRNA. In conclusion, increased plasma glucose concentrations after DEXA treatment were not associated with a stimulation of hepatic gluconeogenic enzyme activities; however, colostrum feeding probably raised plasma glucose concentrations because of increased hepatic gluconeogenic activities.
Language
  • English
Open access status
closed
Identifiers
Persistent URL
https://sonar.ch/global/documents/983
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