PMID- 26074231
OWN - NLM
STAT- MEDLINE
DCOM- 20160301
LR  - 20181202
IS  - 1525-3198 (Electronic)
IS  - 0022-0302 (Linking)
VI  - 98
IP  - 8
DP  - 2015 Aug
TI  - The effects of milking frequency on insulin-like growth factor I signaling within 
      the mammary gland of dairy cows.
PG  - 5422-8
LID - S0022-0302(15)00411-7 [pii]
LID - 10.3168/jds.2015-9425 [doi]
AB  - In dairy cows, short-term changes in milking frequency (MF) in early lactation 
      have been shown to produce both an immediate and a long-term effect on milk 
      yield. The effect of MF on milk yield is controlled locally within mammary glands 
      and could be a function of changes in either number or activity of secretory 
      mammary epithelial cells (MEC). Insulin-like growth factor I (IGF-I) signaling is 
      one candidate factor that could mediate these effects, as it can be controlled 
      locally within mammary glands. Both MEC number and activity can be affected by 
      IGF-I signaling by activating the phosphoinositide 3-kinase (PI3K)/Akt and 
      extracellular-signal-regulated kinase (ERK)1/2 pathways. To investigate the 
      relationship between MF and IGF-I signaling, udder halves of 17 dairy cows were 
      milked either 4 times a day (4x) or once a day (1x) for 14 d in early lactation. 
      On d 14, between 3 and 5 h following milking, mammary biopsies were obtained from 
      10 cows from both udder halves, and changes in the expression of genes associated 
      with IGF-I signaling and the activation of the PI3K/Akt and ERK1/2 pathways were 
      measured. The mRNA abundance of IGF type I receptor, IGF binding protein 
      (IGFBP)-3, and IGFBP-5 were lower following 4x milking relative to 1x milking. 
      However, the mRNA abundance of IGF-I was not affected by MF. Both IGFBP3 and 
      IGFBP5 are thought to inhibit IGF-I; therefore, decreases in their mRNA abundance 
      may serve to stimulate the IGF-I signal in the 4x-milked mammary gland. The 
      activation of PI3K/Akt pathway was lower in response to 4x milking relative to 
      1x, and the activation of the ERK1/2 was unaffected by MF, suggesting that they 
      do not mediate the effects of MF.
CI  - Copyright (c) 2015 American Dairy Science Association. Published by Elsevier Inc. 
      All rights reserved.
FAU - Murney, R
AU  - Murney R
AD  - AgResearch Ltd., Ruakura Research Centre, PB 3123, Hamilton 3240, New Zealand; 
      Institute of Agriculture and Environment, College of Sciences, Massey University, 
      PB 11222, Palmerston North 4442, New Zealand. Electronic address: 
      regan.murney@agresearch.co.nz.
FAU - Stelwagen, K
AU  - Stelwagen K
AD  - SciLactis Ltd., Waikato Innovation Park, Hamilton 3240, New Zealand.
FAU - Wheeler, T T
AU  - Wheeler TT
AD  - AgResearch Ltd., Ruakura Research Centre, PB 3123, Hamilton 3240, New Zealand.
FAU - Margerison, J K
AU  - Margerison JK
AD  - Institute of Agriculture and Environment, College of Sciences, Massey University, 
      PB 11222, Palmerston North 4442, New Zealand.
FAU - Singh, K
AU  - Singh K
AD  - AgResearch Ltd., Ruakura Research Centre, PB 3123, Hamilton 3240, New Zealand.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Dairy Sci
JT  - Journal of dairy science
JID - 2985126R
RN  - 0 (Insulin-Like Growth Factor Binding Protein 3)
RN  - 0 (RNA, Messenger)
RN  - 67763-96-6 (Insulin-Like Growth Factor I)
RN  - EC 2.7.1.- (Phosphatidylinositol 3-Kinases)
RN  - EC 2.7.10.1 (Receptor, IGF Type 1)
RN  - EC 2.7.11.1 (Proto-Oncogene Proteins c-akt)
SB  - IM
MH  - Animals
MH  - Apoptosis
MH  - Cattle
MH  - Cell Proliferation
MH  - *Dairying
MH  - Epithelial Cells/metabolism
MH  - Female
MH  - Insulin-Like Growth Factor Binding Protein 3/metabolism
MH  - Insulin-Like Growth Factor I/genetics/*metabolism
MH  - Lactation/physiology
MH  - Mammary Glands, Animal/*metabolism
MH  - Milk
MH  - Phosphatidylinositol 3-Kinases/genetics/metabolism
MH  - Proto-Oncogene Proteins c-akt/genetics/metabolism
MH  - RNA, Messenger/genetics/metabolism
MH  - Random Allocation
MH  - Receptor, IGF Type 1/genetics/metabolism
MH  - *Signal Transduction
OTO - NOTNLM
OT  - cell signaling
OT  - mammary
OT  - milk synthesis
OT  - milking frequency
EDAT- 2015/06/16 06:00
MHDA- 2016/03/02 06:00
CRDT- 2015/06/16 06:00
PHST- 2015/02/04 00:00 [received]
PHST- 2015/04/22 00:00 [accepted]
PHST- 2015/06/16 06:00 [entrez]
PHST- 2015/06/16 06:00 [pubmed]
PHST- 2016/03/02 06:00 [medline]
AID - S0022-0302(15)00411-7 [pii]
AID - 10.3168/jds.2015-9425 [doi]
PST - ppublish
SO  - J Dairy Sci. 2015 Aug;98(8):5422-8. doi: 10.3168/jds.2015-9425.