PMID- 3034921
OWN - NLM
STAT- MEDLINE
DCOM- 19870710
LR  - 20131121
IS  - 0021-9541 (Print)
IS  - 0021-9541 (Linking)
VI  - 131
IP  - 2
DP  - 1987 May
TI  - Functional differentiation of virgin mouse mammary epithelium in explant culture 
      is dependent upon extracellular proline.
PG  - 190-9
AB  - Depletion of proline from insulin, hydrocortisone, and prolactin-containing 
      medium prior to incubating virgin mouse mammary explants prevents both DNA 
      synthesis and functional differentiation in the mammary epithelial cells; 
      however, DNA synthesis in the mammary stroma and total incorporation of 
      radioactive amino acids into total protein appears to continue without hindrance. 
      Removal of glycine instead of proline had no deleterious effect on either DNA 
      replication in the hormone-stimulated epithelium or in its functional 
      differentiation. Functional differentiation was determined by the induction of 
      casein and alpha-lactalbumin synthesis in the insulin, hydrocortisone, and 
      prolactin (IFPrl)-treated explant cultures. As a control, the induction of mouse 
      mammary tumor virus (MMTV) gene expression, a corticosteroid-regulated function, 
      was also measured. Neither the absence of proline or glycine prevented the 
      glucocorticoid stimulation of MMTV gene expression. In contrast to mammary tissue 
      from virgin mice, explants from nonpregnant primiparous mice responded fully to 
      IFPrl stimulation with respect to DNA, casein, and alpha-lactalbumin synthesis in 
      medium depleted of proline. These data suggest that the uncommitted epithelium of 
      virgin mouse mammary glands requires the presence of exogenous proline in order 
      to respond to lactogenic hormonal signals. We have demonstrated earlier that DNA 
      synthesis is a prerequisite of functional differentiation in virgin mouse mammary 
      explants (Smith and Vonderhaar, 1981, Dev. Biol., 88:167-179; Vonderhaar and 
      Smith, 1982, J. Cell Sci, 53:97-114), although cytological differentiation 
      proceeded unencumbered in explants prevented from synthesizing DNA. Here, without 
      proline, neither cytological nor functional differentiation can be induced; this 
      suggests that proline provides an essential metabolic interlock in the 
      acquisition of lactogenic hormone responsiveness in uncommitted mouse mammary 
      tissue.
FAU - Smith, G H
AU  - Smith GH
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Cell Physiol
JT  - Journal of cellular physiology
JID - 0050222
RN  - 0 (Milk Proteins)
RN  - 9DLQ4CIU6V (Proline)
RN  - AE28F7PNPL (Methionine)
SB  - IM
MH  - Animals
MH  - Cell Differentiation/drug effects
MH  - DNA Replication
MH  - Female
MH  - Gene Expression Regulation
MH  - Mammary Glands, Animal/*ultrastructure
MH  - Mammary Tumor Virus, Mouse/genetics
MH  - Methionine/metabolism
MH  - Mice
MH  - Mice, Inbred C3H
MH  - Microscopy, Electron
MH  - Milk Proteins/biosynthesis
MH  - Organ Culture Techniques
MH  - Proline/*pharmacology
EDAT- 1987/05/01 00:00
MHDA- 1987/05/01 00:01
CRDT- 1987/05/01 00:00
PHST- 1987/05/01 00:00 [pubmed]
PHST- 1987/05/01 00:01 [medline]
PHST- 1987/05/01 00:00 [entrez]
AID - 10.1002/jcp.1041310208 [doi]
PST - ppublish
SO  - J Cell Physiol. 1987 May;131(2):190-9. doi: 10.1002/jcp.1041310208.