Influence of milk cytokines on mammary production of nitric
oxide
S-A. TURNER, D.D.S. MACKENZIE AND C.G. PROSSER
Dairy Biotechnology, AgResearch, Ruakura Research Centre,
Private Bag 3123, Hamilton, New Zealand
E-Mail:
NZSAP 2002 Abstract No. 2
Proceedings of the New Zealand Society of Animal Production 62:
3-6
Cytokines such as interferon-gamma (IFN-y) can stimulate
the production of nitric oxide (NO) from mammary epithelial cells, which
in turn may play a role in intramammary defence of the mammary gland. In
this study, comparisons were made with the production of IFN-y
stimulated NO from Comma-D cells (murine mammary epithelial cell line)
and explants of mammary tissue collected from both pregnant (day 12-14
of gestation) and lactating (day 12-14 postpartum) rats. Response to
IFN-y was measured as the production of nitrate and nitrite (NOx)
in the culture medium. Comma-D cells and explants of mammary tissue from
pregnant and lactating rats responded to treatment with 250 U/ml
IFN-y with an increase in NOx of 5231, 300 and 373% respectively.
The response to IFN-y was lower (P<0.001) in explants than in
Comma-D cells. Inclusion of nitric oxide synthase (NOS) inhibitors
aminoguanidine (100 µM) and Nw-nitro-L-arginine
(1 mM) in the culture medium reduced NOx production by the Comma-D cells
to 31 and 19% of stimulated activity respectively. This suggests that
Comma-D cells are a good model for investigating effects of cytokines on
mammary epithelial cell production of NO, and may also provide a useful
means of screening other milk bioactives for their potential role in
intramammary defence.
Keywords: NZSAPAB;
Comma-D; mammary explants; nitric oxide; milk; cytokines.
Last Updated 30/07/2002
