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Administration of Exogenous Growth Hormone Is Associated with Changes in Plasma and Intracellular Mammary Amino Acid Profiles and Abundance of the Mammary Gland Amino Acid Transporter SLC3A2 in Mid-Lactation Dairy Cows.

Sciascia QL, Pacheco D, McCoard SA - PLoS ONE (2015)

Bottom Line: Treatment with GH increased milk, protein, fat and lactose yields, with no effect on dry matter intake.Variance in the concentration of intracellular lysine, valine, glutamine, EAA and group II was significantly different between treatments.AA changes were associated with increased mRNA abundance of the mammary gland AA transporter SLC3A2.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutritional Physiology ''Oskar Kellner", Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany.

ABSTRACT
The objectives of this study were to (1) identify changes in plasma and mammary intracellular amino acid (AA) profiles in dairy cows treated with growth hormone (GH), and (2) evaluate the expression of mammary gland genes involved in the transport of AA identified in (1). Eight non-pregnant (n = 4 per group) lactating dairy cows were treated with a single subcutaneous injection of either a slow-release formulation of commercially available GH (Lactotropin 500 mg) or physiological saline solution. Six days after treatment, cows were milked and blood collected from the jugular vein for the analysis of free AA in the plasma. Cows were euthanized and mammary tissue harvested. Treatment with GH increased milk, protein, fat and lactose yields, with no effect on dry matter intake. Plasma concentrations of lysine and group I AA decreased significantly, and arginine, methionine, tyrosine and arginine-family AA tended to decrease in GH-treated cows. Concentrations of intracellular glycine, serine and glutamate increased significantly, with a trend for decreased arginine observed in the mammary gland of GH-treated cows. A trend for increased concentrations of intracellular total AA, NEAA and arginine-family AA were observed in the mammary gland of GH-treated cows. Variance in the concentration of plasma methionine, tyrosine, valine, alanine, ornithine, BCAA, EAA was significantly different between treatments. Variance in the concentration of intracellular lysine, valine, glutamine, EAA and group II was significantly different between treatments. AA changes were associated with increased mRNA abundance of the mammary gland AA transporter SLC3A2. We propose that these changes occur to support increased milk protein and fatty acid production in the mammary gland of GH-treated cows via potential mTOR pathway signaling.

No MeSH data available.


Milk, protein, fat and lactose yields of lactating dairy cows treated with growth hormone.Growth hormone (GH) treatment significantly increased milk (A), protein (B), fat (C) and lactose (D) yields from d 4 to d 6, compared to controls (n = 4 per treatment). To assess differences between treatment groups a linear model, including fixed effects of treatment and day effects and their interaction was used. Measurements collected daily over the experiment were treated as repeated measurements using cows within treatment as the subjects, as per Littell et al [22]. The figures show least squares means; Asterisks denote significant differences between treatments (*: P < 0.05); (**: P < 0.01). Error bars denote the standard error of the mean. Milk and protein yield data adapted from Hayashi et al (2009).
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pone.0134323.g001: Milk, protein, fat and lactose yields of lactating dairy cows treated with growth hormone.Growth hormone (GH) treatment significantly increased milk (A), protein (B), fat (C) and lactose (D) yields from d 4 to d 6, compared to controls (n = 4 per treatment). To assess differences between treatment groups a linear model, including fixed effects of treatment and day effects and their interaction was used. Measurements collected daily over the experiment were treated as repeated measurements using cows within treatment as the subjects, as per Littell et al [22]. The figures show least squares means; Asterisks denote significant differences between treatments (*: P < 0.05); (**: P < 0.01). Error bars denote the standard error of the mean. Milk and protein yield data adapted from Hayashi et al (2009).

Mentions: Significant differences in milk, protein, fat and lactose (Fig 1A to 1D) yields were observed between GH and control cows by d 4 of GH treatment. Six days post GH administration, when cows were euthanized and the tissue (blood, mammary) samples collected, milk, milk protein, milk fat and lactose yields were 1.42, 1.40, 1.37 and 1.41 times greater in the GH-treated animals, compared with controls. No difference was observed in dry matter intake between GH-treated and control cows (16.45 ± 0.91 vs. 14.57 ± 1; P = 0.21).


Administration of Exogenous Growth Hormone Is Associated with Changes in Plasma and Intracellular Mammary Amino Acid Profiles and Abundance of the Mammary Gland Amino Acid Transporter SLC3A2 in Mid-Lactation Dairy Cows.

Sciascia QL, Pacheco D, McCoard SA - PLoS ONE (2015)

Milk, protein, fat and lactose yields of lactating dairy cows treated with growth hormone.Growth hormone (GH) treatment significantly increased milk (A), protein (B), fat (C) and lactose (D) yields from d 4 to d 6, compared to controls (n = 4 per treatment). To assess differences between treatment groups a linear model, including fixed effects of treatment and day effects and their interaction was used. Measurements collected daily over the experiment were treated as repeated measurements using cows within treatment as the subjects, as per Littell et al [22]. The figures show least squares means; Asterisks denote significant differences between treatments (*: P < 0.05); (**: P < 0.01). Error bars denote the standard error of the mean. Milk and protein yield data adapted from Hayashi et al (2009).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4520662&req=5

pone.0134323.g001: Milk, protein, fat and lactose yields of lactating dairy cows treated with growth hormone.Growth hormone (GH) treatment significantly increased milk (A), protein (B), fat (C) and lactose (D) yields from d 4 to d 6, compared to controls (n = 4 per treatment). To assess differences between treatment groups a linear model, including fixed effects of treatment and day effects and their interaction was used. Measurements collected daily over the experiment were treated as repeated measurements using cows within treatment as the subjects, as per Littell et al [22]. The figures show least squares means; Asterisks denote significant differences between treatments (*: P < 0.05); (**: P < 0.01). Error bars denote the standard error of the mean. Milk and protein yield data adapted from Hayashi et al (2009).
Mentions: Significant differences in milk, protein, fat and lactose (Fig 1A to 1D) yields were observed between GH and control cows by d 4 of GH treatment. Six days post GH administration, when cows were euthanized and the tissue (blood, mammary) samples collected, milk, milk protein, milk fat and lactose yields were 1.42, 1.40, 1.37 and 1.41 times greater in the GH-treated animals, compared with controls. No difference was observed in dry matter intake between GH-treated and control cows (16.45 ± 0.91 vs. 14.57 ± 1; P = 0.21).

Bottom Line: Treatment with GH increased milk, protein, fat and lactose yields, with no effect on dry matter intake.Variance in the concentration of intracellular lysine, valine, glutamine, EAA and group II was significantly different between treatments.AA changes were associated with increased mRNA abundance of the mammary gland AA transporter SLC3A2.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutritional Physiology ''Oskar Kellner", Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany.

ABSTRACT
The objectives of this study were to (1) identify changes in plasma and mammary intracellular amino acid (AA) profiles in dairy cows treated with growth hormone (GH), and (2) evaluate the expression of mammary gland genes involved in the transport of AA identified in (1). Eight non-pregnant (n = 4 per group) lactating dairy cows were treated with a single subcutaneous injection of either a slow-release formulation of commercially available GH (Lactotropin 500 mg) or physiological saline solution. Six days after treatment, cows were milked and blood collected from the jugular vein for the analysis of free AA in the plasma. Cows were euthanized and mammary tissue harvested. Treatment with GH increased milk, protein, fat and lactose yields, with no effect on dry matter intake. Plasma concentrations of lysine and group I AA decreased significantly, and arginine, methionine, tyrosine and arginine-family AA tended to decrease in GH-treated cows. Concentrations of intracellular glycine, serine and glutamate increased significantly, with a trend for decreased arginine observed in the mammary gland of GH-treated cows. A trend for increased concentrations of intracellular total AA, NEAA and arginine-family AA were observed in the mammary gland of GH-treated cows. Variance in the concentration of plasma methionine, tyrosine, valine, alanine, ornithine, BCAA, EAA was significantly different between treatments. Variance in the concentration of intracellular lysine, valine, glutamine, EAA and group II was significantly different between treatments. AA changes were associated with increased mRNA abundance of the mammary gland AA transporter SLC3A2. We propose that these changes occur to support increased milk protein and fatty acid production in the mammary gland of GH-treated cows via potential mTOR pathway signaling.

No MeSH data available.