title: First-pass uptake and oxidation of glucose by the splanchnic tissue in young goats fed soy protein-based milk diets with or without amino acid supplementation: glucose metabolism in goat kids after soy feeding.
abstract: The study was designed to examine whether feeding soy protein isolate as partial replacement of casein (CN) affects glucose metabolism in young goats and whether effects may be ameliorated by supplementation of those AA known to be lower concentrated in soy than in CN. Goat kids (d 20 of age) were fed comparable milk protein diets, in which 50% of the crude protein was either CN (control, CON), soy protein isolate (SPI), or soy protein isolate supplemented with AA (SPIA) for 43 d (n=8 per group). On d 62 of age, a single bolus dose of d-[(13)C6]glucose (10mg/kg of BW) was given with the morning diet, and simultaneously, a single bolus dose of d-[6,6-(2)H2]glucose (5mg/kg of BW) was injected into a jugular vein. Blood samples were collected between -30 and +420 min relative to the tracer administration to measure the (13)C and (2)H enrichments of plasma glucose and the (13)C enrichment of blood CO2. Glucose first-pass uptake by the splanchnic tissues was calculated from the rate of appearance of differentially labeled glucose tracer in plasma. Glucose oxidation was calculated from (13)C enrichment in blood CO2. In addition, plasma concentrations of triglycerides, nonesterified fatty acids, glucose, insulin, and glucagon were measured. On d 63 of age, kids were killed and jejunal mucosa and liver samples were collected to measure lactase mRNA levels and lactase and maltase activities in the jejunum and activities of pyruvate carboxylase and phosphoenolpyruvate carboxykinase (PEPCK) in the liver. Basal plasma glucose concentration tended to be higher in the CON than the SPIA group, whereas basal insulin was higher in the CON group than the SPI and SPIA groups, and glucagon was higher in the CON than the SPIA group. Plasma glucose and insulin concentrations increased during the first hour after feeding, whereas plasma glucagon increased immediately after feeding and after 1h of feeding. First-pass uptake and glucose oxidation were not affected by diet. Maltase activities in proximal and mid jejunum and lactase activities in mid jejunum were lower in the CON than in the SPIA group. Activities of PEPCK were higher in the SPIA than in the SPI group. In conclusion, feeding milk diets with soy protein isolate seems to affect glucose status in kids, but has no effect on first-pass uptake and oxidation of glucose. The highest activities of lactase and maltase were observed after supplementation with AA. Higher PEPCK activities in the liver may point at elevated gluconeogenic activities after AA supplementation in soy-fed kids.
authors: Department of Nutritional Physiology "Oskar Kellner," and. Electronic address: schoenhu@fbn-dummerstorf.de.
authors: U
authors: U
authors: Schönhusen
authors: Department of Nutritional Physiology "Oskar Kellner," and.
authors: P
authors: P
authors: Junghans
authors: Department of Nutritional Physiology "Oskar Kellner," and.
authors: A
authors: A
authors: Flöter
authors: Department of Nutritional Physiology "Oskar Kellner," and.
authors: J
authors: J
authors: Steinhoff-Wagner
authors: Department of Nutritional Physiology "Oskar Kellner," and.
authors: S
authors: S
authors: Görs
authors: Department of Reproductive Biology, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
authors: F
authors: F
authors: Schneider
authors: Department of Nutritional Physiology "Oskar Kellner," and.
authors: C C
authors: CC
authors: Metges
authors: Department of Nutritional Physiology "Oskar Kellner," and.
authors: H M
authors: HM
authors: Hammon
mesh_terms: D000596:Amino Acids / Q000008:administration & dosage*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D005943:Gluconeogenesis; D005947:Glucose / Q000008:administration & dosage / Q000378:metabolism*; D006041:Goats / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000187:drug effects / Q000201:enzymology; D043322:Lactase / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D008894:Milk Proteins / Q000008:administration & dosage; D010084:Oxidation-Reduction; D045730:Soy Foods; D041942:Soy Milk / Q000008:administration & dosage; D030262:Soybean Proteins / Q000008:administration & dosage; D000520:alpha-Glucosidases / Q000378:metabolism
chemical_list: D000596:Amino Acids; D001786:Blood Glucose; D008894:Milk Proteins; D030262:Soybean Proteins; D043322:Lactase; D000520:alpha-Glucosidases; D005947:Glucose